How to Start a Beautiful Cut Flower Garden
Why Grow a Cut Flower Garden?
There are plenty of reasons to grow a cut flower garden. The first being that a cut flower garden allows for the sensual experience of flowers.
If you’ve gardened before, it’s common to let the flowers bloom on the plants - whether a bulb, annual, perennial or woody shrub or tree and enjoy them in the setting of the garden. This is certainly a great way to enjoy flowers, but when you are able to cut flowers to enjoy indoors - particularly flowers that are grown specifically for their ability to be enjoyed as cut flowers in a vase - it takes your enjoyment to a whole new level.
Flowers that are beautiful when enjoyed out in the garden are so much more intense, so much more beautiful and take on new properties when cut and brought inside. By being able to view these flowers up close, in the intimacy of your home, you gain quite a different perspective - and experience them - in a very different way.
A single stem of a sweet pea, cut and brought into the home can perfume an entire room with its heavy, gorgeous scent, the way that its delicate petals curve and fold, the way the stem twists and holds each bloom aloft - this is a beauty that you cannot necessarily experience outside.
This past year, I also think that many people have learned the joy of growing a garden - and although vegetable gardening has been the obvious go-to for many people, the joys of cut flowers are another experience altogether.
The absolutely luxurious experience of gathering a bouquet of flowers to then arrange in a vase or urn, or even just a single beautiful perfect bloom cut to enjoy on your bedside stand or your bathroom is phenomenal. Every single time, I find myself feeling so lucky, so blessed, so rich to be able to cut flowers for pleasure.
Cut flowers also make for the perfect way of bringing joy or comfort to someone that may need it. This year has also been unfortunately heavier for many people - and I found that bringing cut flowers is something very special, very powerful for helping someone through those heavy emotions and to feel better.
Even more, cut flowers are generally wonderful for the environment in general. Many cut flowers such as poppies, zinnias and sunflowers are wonderful sources of pollen and nectar for a host of species, while the wide diversity of plants allow for the creation of a habitat (and subsequent attraction) for a multitude of species including (but not limited to) assassin bugs, praying mantises, spiders, frogs and toads, birds, and more wildlife. When the seed heads and seed heads of the flowers are left during the winter, they can also function as a shelter and a food source for wildlife as well.
Whatever your reason for growing a cut flower garden, I always think that growing more flowers is a good thing.
NOTE: If you are looking to grow cut flowers as a small business, whether through selling floral arrangements directly or wholesale to floral designers, you may want to read our thoughts on becoming a flower farmer (the good and the bad)
With that being said, onto the guide of How to Start a Beautiful Cut Flower Garden!
How to Start a Beautiful Cut Flower Garden
The Mission: Growing Flowers, Made Simple
Planning and Designing Your Cut Flower Garden
The Mission: Growing Flowers, Made Simple
As professional flower farmers and floral designers, we’ve grown a lot of flowers over the years. Thousands of stems, hundreds of plants, and countless bouquets and arrangements, all while tweaking and experimenting and learning how to grow flowers - lots of flowers - easily and efficiently.
We have grown on a very large scale, but we grow on a smaller scale now. Despite our smaller scale, the lessons we’ve learned as large-scale professional growers we have found apply very well to personal gardening. You also don’t have to have acres of cut flowers to be able to appreciate their beauty or to gather enough stems to make a small arrangement for you to enjoy.
The strategies, techniques, equipment and knowledge that we have learned over the years in growing beautiful cut flowers are the ones that we’ll share with you here. Whether you’re growing for selling buckets of flowers or just enjoying a few stems to cut and enjoy yourself, many principles are the same.
Planning and Designing Your Cut Flower Garden
Planning
When it comes to the cut flower garden, we like to have a good variety of flowers and materials. Both because it helps to ensure that we have all the necessary elements to create a nice bouquet or arrangement (focal flowers, secondary flowers, filler flowers, foliage and line material) as well as to always have something in bloom throughout the year.
We’ve grown flowers long enough to know what flowers work well together and when they bloom - but for the purposes of starting a cut flower garden (especially if you’ve never grown any flowers before) we’re recommending a set variety of flowers that will provide a good range of color, shape, texture, form and scent.
Take for instance our 2021 spring line-up:
Orlaya
Foxgloves
California Poppies
Clary Sage
Sweet Peas
Linaria
Ornamental Cress
This flower line up consists of a color and flower palette that will work perfectly together to ensure both striking visual beauty as well as good productivity. The flowers will work well into both retail bouquets and arrangements as well as if I want to use them in floral design or wedding work.
How did we go about choosing these flowers? There were a few traits that we looked for in each species:
Cold hardiness - (This is applicable to spring-blooming flowers) All of these varieties are pretty cold hardy, being able to withstand temperatures down to around 15 degrees or so, which means we can plant them earlier and get a bigger head-start on the season.
Easily grown from seed - Unlike some varieties of plants (hello eucalyptus and lisianthus) these are all relatively easy to start from seed, growing quickly and profusely without much error
Productivity - All of these varieties are cut and come again varieties, meaning that we’re able to get multiple harvests off the plant and ensure that we’re getting the maximum production of cut flowers per square foot of bed.
Beauty - Every single flower we grow is something that I like visually. After all, that’s half the joy of growing all this - whether it looks good in a bouquet or in a vase on its own. And while some of the flowers may have some negative traits - shorter vase life, short bloom period, fewer blooms - they are worthy enough in some respect to make them part of our lineup.
If you want to follow along with us as we grow our own cut flower garden this season, you should join our Facebook group. You’ll get to interact with other gardeners and growers and ask questions directly there!
A private group for flower lovers, gardeners and growers to learn and grow together
Preparing Your Growing Area
Once you have decided what it is you want to grow and you’ve got a plan sketched out, it’s now time to prepare your growing area.
If you’re lucky enough to have a bare patch of soil ready for you to start growing in, consider yourself blessed. If you have to do some work to get it ready, that’s also okay - just remember that you’re setting the foundations for a healthy and easily maintained growing area in the future.
It’s important first of all to remove any obstructions or obstacles in the area. Whether that’s rocks, tree roots, tree branches or other junk, get rid of it. The fewer items you have mucking up your soil and preventing you from in essence moving freely through it with a tool or a plow, the better off you’ll be and the easier it will be to grow and maintain.
It’s also important to remove as many weeds as possible. Whether that’s perennial weeds like Johnsongrass, dock and bindweed or annual weeds like quackgrass, dandelions and Palmer’s amaranth, you want your beds to be as free of weeds as possible.
This is the best time (and easiest time) to remove any weeds that are growing in your beds when you don’t have to worry about other plants (desired plants) that you might disturb in your attempt to remove the weeds. Just get in there and dig and pluck and pull everything that you can.
on Designing in Flower Rows
Most flower farmers grow their flowers in rows. This is in contrast to the usual gardening or landscaping designs that usually have either swathes, clumps or other less linear designs to their plantings.
Why rows? When grown in straight rows, growing cut flowers is much easier for a few reasons:
1) Infrastructure: It is very easy to run drip irrigation, netting, staking, floating row cover and trellising down a straight row. Not so easy when you’re dealing with any other configuration or shape!
2) Maintenance: Keeping the cut flowers weed-free or free of pests is very easy to do. The uniform spacing and formation allows for the easy identification and removal of weeds or pests.
3) Harvesting: When you’re harvesting stem after stem of flowers, you’ll want to make it as easy and efficient as possible. Harvesting in straight rows is the most efficient and easiest way to do it instead of having to hodge-podge your way through a border or garden bed.
A cutting garden can be fashioned in the same way - in long rows or grid system to allow for easy maintenance and harvesting!
These rows are 36” wide rows to be exact, and usually around anywhere from 20’ to 100’ long (depending on the size of your property and orientation of your beds).
Why these measurements? 36” is the perfect size to maximize the production of your flowers in the bed while also keeping the bed easily maintained. Most people can reach into the middle of a 36” bed very easily (a 48” bed is too wide for most people to be comfortable working in). It also allows for you to plant a lot of flowers into that bed.
Length is debatable, but generally speaking most people will create their beds based on 5’ increments to ensure that other equipment like row cover and netting will fit them nicely. It’s also easy to round up to 5’ or 10’ increments. Of course if you happen to live in an area where you go by the metric system, you may want to adjust your measurements to better fit your supplies available.
Since we’re growing intensively, I always just leave a mere 12-18” between the beds. They are more like 12” for the most part to maximize the number of beds and the ground in production, which is just wide enough for me to squeeze through in order to harvest flowers and weed.
Preparing the Soil
While there are plenty of people that get into very detailed specifics regarding soil and preparing your area, I’m not quite as fastidious when it comes to soil.
Whether it’s just good upkeep and management of the soil, an inheritance of good soil or just pure luck, everyone seems to have a unique situation regarding their own soil and planting. It’s always good to have a professional soil test taken to see where your soil may need amending and what its profile looks like.
That being said, a lot of flowers can grow in just about anything - even the crappiest, heaviest soil out there. Some of the more rugged flowers like strawflower, sunflowers, cerinthe and scabiosa actually really like poor soil that has more similarity to gravel than humus.
You’ll need to figure out if yours will need any amendments and then add them accordingly. Its best to mix the amendments into the soil and into the individual beds to ensure that the amendments are condensed into your growing area where your plants will be growing in.
I’ll also add some organic granular fertilizer into the bed to ensure that the plants have all the nutrients they need once they start growing. Our soil is particularly low in nitrogen, so I’ll usually add blood meal or feather meal to boost that.
While some people use a tiller to prep their soil, our smaller area is not too hard for me to mix in and amend by hand. Although you can use a tiller, I prefer to leave more of the soil intact to ensure that more of the soil’s structure remains. It’s also a lot less work to not till such a small area.
Landscaping Fabric and Mulches
For many flower farmers, they utilize a thick and heavy woven plastic landscaping fabric with holds burned or cut into it at set intervals. More like a plastic-y tarp or canvas, they have been present in farming and agricultural purposes for quite a while.
Most flower farmers use this for weed suppression. I mean, you’ve set up the perfect growing environment for most plants in your beds - good rich soil and regular moisture and irrigation - and weeds can very quickly overtake your plants. The fabric keeps weeds from sprouting and allows for the flowers to have the upper hand when planted directly into it.
We personally don’t use landscaping fabric or any sort of plastic mulch with our plants. We have a very unique growing situation in that our conditions are so dry and have so little moisture that the weed competition is very easily managed.
It’s also so hot and sunny here that a black plastic mulch or landscaping fabric would cause the soil and plant to heat up to the point where it would kill the plant (have you ever seen dahlia tubers cook under black plastic? It’s not pretty to see steam rising up from your recently-dead plants). Again, it’s going to be based on your situation whether or not you use landscaping fabric or plastic mulch around your plants.
Irrigation and watering
This totally depends on your circumstance, but I would recommend drip irrigation over other types of irrigation for a few reasons.
The first is that drip irrigation is super efficient as far as watering. The water goes right to where it should (the roots of your plants) and is not wasted anywhere else. Every single drop of water is delivered to the plant and nowhere else, and I like the precision by which we can deliver it. (A great tip that I learned from an experienced grower, we like to bury our drip irrigation a few inches below the surface of the soil, which makes it even more efficient and prevents weeds from growing as a result of a lack of moisture. It also helps that being buried underground prevents water from evaporating, ensuring that it is even more efficient with the watering.)
The drip irrigation also has pre-built emitters at 6” apart - which helps to be able to space out seedlings properly when planting. A 6” spacing ensures that the soil will be evenly moistened and not have a lot of dry patches that can occur with other spacing.
We use a ¼” plastic tubing - it’s very durable and will last for years (we still have drip irrigation from 6 years ago that is going strong - being buried will help to prevent damage from UV and cold temperatures). And in fact the only issue we’ve had is with the occasionally overly-zealous use of a shovel or a trowel or soil knife that accidentally cuts through a tubing - otherwise it has been absolutely perfect to work with.
The drip irrigation is very time efficient when it comes to watering too. Whereas using an overhead sprinkler or watering wand requires you to either move the sprinkler or move the watering wand around to ensure everything gets watered, the drip irrigation just needs to be turned on - and it will slowly and evenly distribute the moisture right to your plants. I like too that the slow distribution of the water ensures that there is no issue with runoff or water splashing on foliage (which can contribute to fungal disease like rust and powdery mildew).
If you still have to water using an overhead source like a sprinkler or a watering wand or hose, it still can be done. We do have friends who grow using these methods because it’s the best and most efficient way for them to water their flowers so again it is very situational as far as the right solution for you.
Fertilization and nutrition
You may remember that I’ve already recommended to use a granular organic fertilizer when prepping your beds, which is a good start. I find that this organic fertilizer is enough for planting small seedlings into and even getting to the first flush of blooms - but to keep them going I recommend using a secondary water-soluble fertilizer to keep your plants in good condition and producing.
I really like Fox Farm’s Tiger Bloom fertilizer - it’s an extra concentrated solution of all sorts of good stuff including earthworm castings and kelp that ensures your plants get the nutrition that they need to grow well and continue to produce lots of flowers for you.
While other people swear by spraying the leaves (known as foliar feeding) I haven’t found much peer-reviewed evidence regarding supporting of foliar feeding. Instead, I’ll just pour it into a watering can and drench the soil around the plants so that it soaks into the soil and down to the roots where it can be taken up by the plants.
Since this growing area is so small, I’ll just fertilize by hand on a weekly basis (it takes me about ten minutes to do the whole area). Of course if you were growing on a larger scale this would be terribly inefficient, but I find that this approach works well on a smaller scale.
If you really want to automate your fertilizing system, you can also utilize what is known as a Fertigator - a pressurized system that allows you to fertilizer while you use your drip irrigation system, delivering drops of water with the liquid fertilizer in it right down to the roots of the plants where they need it.
Netting and Staking
When you’re growing flowers, you’re going to want to have netting. Or at least a trellis of some sort to support your plants. For instance, bachelor buttons can get as tall as 4’ - and if you don’t provide them some sort of support they will flop over and make it impossible to get good straight stems for arranging with.
Some people utilize plastic netting - usually used as a support for growing peas or beans or other vines - that is instead flipped horizontally over the bed and the plants are allowed to grow through it. Although it seems very flimsy, the plastic netting will actually work wonders in keeping your plants straight and upright, keeping those stems long and straight and beautiful.
For larger, bulkier plants like amaranthus, branching sunflowers and hibiscus ‘Mahogany Splendor’ we will instead utilize a corralling system using twine wrapped on the exterior of the bed to be able to keep the plants from flopping over. It’s not always perfect - there always seems to be at least one plant that ends up toppling over despite our best efforts - but it works well for 99% of our beds.
We like to use large timbers or bamboo at the four corners of each bed that we then slide the plastic netting or twine over until it is taut. Some people also use metal T-posts that they can hammer into the ground, which is totally fine as well (I just always seem to run into them when I’m working on the flower beds, so I’ve taken to just using wood so I don’t put out my eye!)
For dahlias, we prefer to use bamboo stakes to stake them individually. Although we used to use the corralling method when we were growing hundreds of dahlias, now with a much more manageable amount of dahlias we can stake them to a single piece of bamboo growing upright.
For sweet peas and other vining plants such as love-in-a-puff vine and nasturtiums, we will erect the same trellis netting running lengthwise through the bed and plant either side of it. The plants will then vine upwards, attaching itself to the netting, allowing it to grow vertically. The netting is attached to a very sturdy wooden or bamboo stake every four feet to support the plants.
Floating row cover and low tunnels
Floating row cover (aka frost cloth, aka Garden Fabric) is a very useful thing to have as a flower farmer. It has a variety of uses including:
Providing protection against winter cold and wind (the main one)
Keeping the soil warm during the colder months to allow for earlier seed germination and earlier soil warmth
Protecting soil from collecting weed seeds
Lending protection from the sun and wind while hardening off your seedlings
Protecting seedlings during transplanting from the sun, wind, and predators
Protecting certain flowers, such as ornamental kale from insects that could destroy your crop
Keeping up the moisture in soil to allow for seeds to germinate and for transplants to establish themselves
Creating shade to allow for longer stems by causing plants to stretch towards the light
We have a lot of floating row cover that we can use for any number of applications, and it has proved invaluable. When properly taken care of (rolled up carefully and stored when not needed in particular) it will last for years.
The most important use for floating row cover for us is providing protection against cold temperatures for our spring blooming garden. Floating row cover can help to prevent the worst of cold temperatures from freezing plants that may potentially be damaged or even killed off by a drop in temperatures - specifically the spring blooms that do very well with a fall or early spring planting to give them a very long and cool establishment period that allows them to grow good root systems that then translate into excellent, productive plants with lots of big flowers.
We’ll cover our seedlings and plants with the row cover basically until around the last frost date - the row cover will allow for them to grow lushly and full underneath the fabric. It’s like growing in a little greenhouse - but without the maintenance and attention required by a greenhouse.
If it gets really cold, we’ll add additional row cover layers in order to provide greater protection. It will only provide a little bit of cold protection when it comes to lower temperatures below 25, but it will help to protect them from freezing and frost damage by keeping in the moisture.
We also use row tunnels to help our flowers get a head start in the form of wooden or metal hoops that form a very short (2-3’ tall) “tunnels” over the bed. We use floating row cover on our tunnels, but you can also use clear plastic to add additional cold protection. Just be careful using plastic - it can heat up very quickly in the tunnels, even during the middle of winter and can get up to over 100 F (you end up actually cooking your plants!) so if you use plastic for your tunnels you will have to open up a side of the tunnel to allow it to vent out the heat. It frankly takes a lot of work, and is a full time job for the flowers farmers that use them, which is why we only use floating row cover (it breathes very easily and doesn’t require us to open up the tunnels when it gets warm).
How to start seeds for your cut flower garden
Starting seeds for a cut flower garden can be immensely rewarding - even magical. Transforming small seemingly inanimate seeds that will sprout, grow and finally bloom seems to be the work of magic - an alchemical feat that seemingly defies logic sometimes.
Even more amazing is the fact that each seed will go on to produce large plants in a few months' time that will bloom and produce armloads of scented, beautiful, colorful flowers for you to enjoy. One single zinnia seed for example will go on to produce at least a dozen flowers over the growing season - highly impressive!
If you’ve never started seeds before, there’s never been a better time to learn how! I have a couple guidelines that will help you ensure you’re successful with your seeds.
Good seed starting practices
There are a few things to keep in mind when growing flowers from seed that will help you to ensure success.
Use the proper equipment and materials
Give your seeds the proper amount of moisture
Give your seeds the proper amount of light
Know the requirements of the seeds you’re starting (I’ll cover this below in great detail)
Make sure to harden off your seeds before planting them out
Each of these individual steps can lead to the loss of your baby plants along the way - which means that sometimes weeks if not months of hard work are lost! If you can follow these steps, you’ll find that your seed starting will be much more consistent, successful, and easier.
Using the proper equipment and materials
Although it’s a poor tradesperson who blames their tools, the correct tools and materials can make a world of difference when it comes to starting seeds. I’ve tried a multitude of seed starting equipment and strategies over the years, and have sorted out the ones that work well and are the easiest to take care of.
The best: cell inserts with trays and humidity domes
This is the standard seed-starting equipment for most growers due to their versatility, sturdiness and longevity, and their effectiveness.
The cell inserts are what you actually put you soil and seeds into
The tray is what you put the cell inserts into, allowing for you water them and keep them contained or corralled
The humidity dome goes on top of the tray, allowing for you to keep up the levels of humidity and allow for the seedlings to grow and gain in size
Here’s how we use them
Fill your cell inserts with potting mix, ensuring that you tamp down the surface of the soil to remove any air pockets
Place the filled cell insert into the tray
Add enough water to fill the tray ¼-⅓ up the sides of the tray and let the potting mix in the cell inserts wick the water upwards
Place a humidity dome on top of the tray to keep up the humidity and encourage germination
When your seedlings have grown to the point where you want to start hardening them off, you can either vent open the humidity dome or crack open the humidity domes an inch or two for a few days
Equipment that didn’t make the cut
Soil blocks are famously popular among flower farmers. I really like them in concept - there’s a lot to like about them especially with the amount of seedlings you can start in a very small area - but I think they are better relegated to the vegetable farming world than they are the cut flower world.
My reason is because soil blocks tend to dry out very, very quickly and once the seedlings get to the size where you should be planting them out, they may take watering 2-3 a day just to keep them moist, and I’ve lost more seedlings than I would like to admit as a result of that.
I also don’t really enjoy the process of making soil blocks since I can fill a 72 cell tray with potting mix in around ten seconds with a motion that does not hurt my hand and doesn’t require the same finesse that soil blocking does. It also allows me to grow a wider variety of seedlings, including perennial seeds that take a longer time to develop a good root system.
That being said, it’s very popular and many flower farmers get good results with soil blocks. I wrote how to use soil blocks for flower farming and how to use them to start seeds for a cut flower garden as well below:
Soil blocking - the pros, the cons for flower growing and how to do it successfully
All of the coir and peat based stuff, including the pots and the expandable pellets are rubbish when it comes to growing good healthy seedlings - they aren’t able to be watered correctly, the roots never develop quite right and the plants really just never perform the way they should.
And lastly, newspaper pots, yogurt cups, recycled plastic containers and egg cartons are terrible - they never hold soil properly, will either fall apart or stay too wet, and you’re not going to have great success.
Potting Mix
It’s important to start your seeds in the correct type of soil. If you don’t, the roots and plant won’t develop properly, and you’ll end up with unhealthy, stunted seedlings that just never will work well for you.
To grow healthy, happy plants, start with a good soil mix.
What makes for a good soil mix? Ideally a finely sifted compost would work well, mixed with a bit of perlite or vermiculite, but you can also find commercially prepared soil mixes that work well for starting seed. We particularly like Promix HP for professional flower growing, but this Seed Starting Mix works very nicely, with a very fine and even texture as well as the addition of mycorrhizae for healthy and robust young seedlings.
You definitely don’t want to use anything that is chunky or coarse in texture - this will result in your seeds having to fight their way through the medium when growing - and you don’t want to use anything that has large pieces of bark or wood in them. If your soil or compost has a lot of big pieces in it, use a sieve to sift out the bigger pieces and leave you with a finer mixture.
If you’re interested in learning more how we start seeds for a wide variety of cut flowers as professional flower growers, you can download our FREE ebook for seed starting below:
Seed starting is one of the most important skills a flower farmer can have in ensuring the success of their farm and business, and can also be one of the more frustrating aspects of flower farming as well. In this book we demystify the art of germination and share our secrets to seed starting including our equipment, techniques, successions, growing out, hardening off and transplanting, as well as a detailed guide to germination for specific species. An excellent read for the beginning flower farmer new to seed starting!
Give your seeds the proper amount of moisture
Moisture is extremely important when it comes to seed starting.
Water is literally the magic ingredient when it comes to germinating seeds. Like the famous California wildflower blooms illustrate, seeds can lie in wait for years and years, coming alive in a flurry of growth when the rains come.
It’s important however, to ensure that you give your seeds the correct amount of moisture. Too little, and the seeds will dry out before they’ve properly germinated, trapping the baby plant inside the seed and never letting it grow out. Too much and the seeds may drown or rot.
How do you know how much moisture to give your seeds? It may depend on the type of seed - certain seeds like Icelandic poppies do well with a little bit less moisture, while certain seeds like basil do well with a bit more moisture - but generally you want the soil of your seeds to be moist, but not flooded or saturated with water.
Think the moistness of a wrung-out sponge. Or a moist brownie or cake.
The best way to do this? Water from the bottom and let the soil do the rest. When immersed in water, the moisture travels into the soil via capillary action until the entirety of the soil is evenly and completely saturated with water.
When we bottom water, we fill the cell tray with water (about halfway up the sides) and then place the cell tray inserts into the cell tray. After letting the soil saturated completely with water, we let the excess drain off afterwards.
This not only allows for the even, perfect watering of your cell tray inserts (and the soil and seedlings in them) but it also allows you to water without disturbing the seeds on top of the soil. Small seeds like foxgloves, poppies and snapdragons can get washed away or float off the surface of the soil if you water from the top, so this keeps them in place. You can even add in fertilizer and nutrients into the water later on to give your seedlings additional nutrition (we like adding fish emulsion and kelp fertilizer to young seedlings).
Give your seeds the proper amount of light
Lighting will be important when your seeds start to germinate.
Most seeds don’t need light to germinate (or at least not a lot of it) but after they start growing, they need all the light they can get.
Take for example sunflowers. They are definitely full-sun flowers, and if they do not receive enough light they will be sad, spindly, terribly weak little seedlings that won’t survive outside. And even if they do, they will be terribly deformed, floppy, unproductive plants (we’ve gotten to the point where if we let our seedlings get to this point, we just start over. It’s not worth it at this point).
So the most power light possible is important. We’re talking either full sunlight (the best) partial sunlight (if your seedlings prefer shade) or under artificial light (2-3 inches away from the bulbs).
We do not use the sunlight from windows to start seeds, since it is not powerful enough (there’s not just enough light).
Know The Requirements of the Seeds You’re Starting
Some seeds require different conditions to germinate. Let’s go over a couple of the different types of seeds.
Heat-loving seeds: These seeds do well with warm and humid germination conditions. These are the majority of seeds that are grown for a cut flower garden.
Winter-loving seeds: These seeds need cold temperatures in order to germinate - freezing temperatures actually.
Dark-loving seeds: These seeds need to be totally covered in order to germinate - and ideally kept in total darkness for the best germination.
Heat loving seeds are naturally primed to germinate when they get heat and moisture - these act as the triggers to cause these seeds to come alive. If you think about it, heat and moisture would generally signal that spring has come - heat from the longer days and the sun warming the earth, and the moisture that comes from spring rains or precipitation of some sort.
Most seeds are triggered by these conditions to germinate and start growing. These seeds will germinate very quickly and uniformly when you apply heat and moisture.
Professional flower farmers will oftentimes use what is known as a germination chamber - a heated moisture-retentive container that allows them to start dozens of flats of seeds at a time.
You may not need a germination chamber, but there is another way to start these seeds readily and quickly and that is with a heating mat. Plugged into the wall to provide a safe, steady, gentle source of heat. Combined with humidity domes over your seeds, it will provide the heat and moisture that your seeds need to start growing.
You’ll see the seeds start to germinate - sometimes in the form of tiny little silvery sprouts as the tip of the root starts to poke out from the seed, sometimes in the form of itty-bitty leaves, hardly bigger than a pinhead.
After your seeds start to germinate, it’s important to provide them with the proper growing conditions. These seeds can be divided into two groups based on growing conditions- spring blooming and summer blooming. Spring bloomers like sweet peas, poppies, nigella and foxgloves do best when they grow in bright cool conditions, while summer bloomers do best when they grow in bright warm conditions.
If you try and grow spring bloomers in warm conditions, they will get leggy and spindly and turn into very wimpy plants that have a questionable chance of surviving. If you try and grow summer bloomers in cool conditions, they will grow very, very slowly - and in some cases can even start rotting if the soil remains too cold for too long. So best to grow your seedlings when you have appropriate conditions.
For our spring bloomers, we will start them off on heat mats until they germinate and just start to sprout. Afterwards, we’ll transfer them to a sheltered outdoor area to allow them to grow in bright and cool conditions. If it gets too cold - below 20 degrees is pretty cold for us - we’ll bring the seedlings indoors at least temporarily until it gets warmer outside.
NOTE ON HARDINESS ZONES: I should mention that we usually only get to around 20 F on average, and are a Zone 7b as far as winter hardiness zones. This means that we can grow annuals that are hardy to around 15 F (which you can see in the chart below). If you live in a Zone 6a or colder, I may recommend only starting your seeds 6-8 weeks prior to your last frost date to ensure that you don’t lose your seedlings. You will want to read below about hardiness zones and varieties of flowers - it will be the most important thing you read to plan and grow your spring-blooming garden.
THE IMPORTANT POST: Hardy Annuals (Hardiness zones and the RHS hardiness ratings
For our summer bloomers, we’ll start these seeds on the last frost date in our area. This will give us time to enjoy our spring-blooming flowers before we replace them with summer bloomers, which will be happy to be growing outdoors without any risk of frost or cold conditions that may slow their growth.
Winter-loving seeds such as Queen Anne’s Lace (Daucus carota) are particularly unique because they have a requirement for cold in order to germinate. These seeds require the chill of a cold, moist winter in order to trigger their ability to germinate. All seeds have a different chilling period, but generally 90 days of cold (30-40 F) and moist conditions will allow these seeds to start germinating.
There are a couple ways of doing this. I generally will plant these seeds in a tray or cells with a fine seed-starting mix, water it well and then place it outside starting in December. This will allow for enough cold temperatures and moisture to occur, and your seeds will then start popping up once the days get longer and the temperatures start to warm.
If you live in a place that doesn’t get cold enough consistently to provide this treatment, you can also pop the same seeds into a small pot or module and then place it in your refrigerator and chill it for the same amount of time.
Once these winter-loving seeds have been in the cold for a long enough period, we will then place them onto heat mats and then grow them out the same way we would our usual spring-blooming seeds. If timed correctly, we can have our winter-loving seeds and our heat-loving (spring blooming) seeds all growing at approximately the same time
Dark-loving seeds - of which there are only a few - are unusual in that they require complete darkness to germinate. Chinese forget-me-nots (Cynoglossum amabile) annual phlox (Phlox drummondii) sweet peas (Lathyrus odorata), bupleurum (Bupleurum griffithii), violas and pansies (Viola spp.), nasturtiums (Tropaeolum) and a few others require the seeds to be buried under the surface of the soil.
I personally also like to ensure greater darkness by placing an upturned seed tray or a piece of dark plastic to go over the tray to ensure it is completely dark.
The main issue with dark-loving seeds is that it’s hard to tell when seeds pop up and start germinating. It’s important that when you start those seeds that you check on them regularly to ensure that when they start germinating you’re able to get them quickly out under some light. All of these seeds also happen to be spring-bloomers, so you’ll want to get them into cool and bright conditions as well.
You can learn a lot more about seed starting (including getting hard-to-germinate perennials to grow!) in these comprehensive posts below:
cut flower hardiness zones and seed requirements
Not sure when to start your seeds or when to plant them out? This comprehensive post will inform you just how cold hardy your flowers are
Growing on seedlings
As mentioned previously, once your seeds have germinated and are starting to sprout, it’s important to get them out to an area with as much light as possible, preferably with the addition of some shelter to prevent winds and rain and other inclement weather from messing with your seedling.
You can do this one of two ways - you can either continue to grow them indoors and under lights, or you can put the outside to grow.
When it comes to spring blooming plants, we’ll generally grow them out to a decent size under lights, and then will move them outside to continue growing. The reason for this is usually at the time of year when we’re starting out seedlings for spring blooms (December, January), the temperature and light doesn’t allow for seedlings to grow very well or quickly (colder temperatures and shorter hours of daylight that is).
Instead, we’ll grow out our seedlings from when they are teeny-tiny germinated sprouts all the way to small, young seedlings under lights to give them a good head start. After they’ve reached this point, we’ll then set them out to harden off and plant them out in the warmer temperatures of February (and then continue to grow protected under floating row covers on our low tunnels).
For summer blooming flowers, we generally will start them out also under lights indoors (to allow for a head start if the spring is cool) or we will start them directly outside in flats.
The seedlings don’t have to grow here forever - we generally want them to get a good root system, enough to fill up the entire cell before transplanting them out. This may happen relatively quickly (such as with sweet peas and bachelor buttons) or it may take a bit longer (such as with Icelandic poppies and foxgloves) - but we want their root systems to be fairly well developed prior to planting them into the ground.
HArdening off seedlings
Once you’ve gotten your seedlings grown out, it’s time to harden them off.
What is hardening off? Hardening off is the term used by gardeners and growing professionals to describe the process by which you get seedlings (or plants) acclimated to being able to deal with being outside.
When plants are grown inside, they have it pretty plush and easy. High humidity, no wind, warm temperatures and being lit by artificial lighting make for soft, tender, succulent plants.
Outside? It’s quite a different story. Plants have to deal with fluctuating humidity, wind that can dessicate or even shred tender foliage and leaves, fluctuating temperatures that can be super hot or freezing cold, intense lighting from the sun, and all matter of precipitation including snow, sleet and rain.
To prepare your baby seedlings for going out into the world, you have to toughen them up and let them adapt slowly and gradually to the conditions outside - “hardening” them to the conditions so to speak.
While the traditional wisdom has been to move them in and out of the indoor growing area (and this works well if you’re a professional grower and have large racks of plants you can wheel in and out of a greenhouse) we’ve developed a much easier way to harden seedlings off.
First of all, you’re going to want to pick a relatively mild week to harden off your seedlings. Don’t try and do it during the middle of a polar vortex or a heat wave, because your seedlings will suffer more than they have to. Instead mild weather will help to ensure that they get a soft and gradual and incremental acclimation to the temperatures and weather of the great outdoors.
Secondly, we’ll pick a sheltered area to harden them off in. Put them in a place that will be protected from wind and rain and other precipitation (you especially don’t want to have them in a place where they’ll be drowned by a sudden downpour of rain). We have a back porch that has a covered metal roof, but is otherwise open to the elements - the perfect place to harden off our plants.
Third, we’ll just put our seedlings outside with a layer of floating row cover on them - this will work to protect them from harsh temperatures, sunlight, changes in humidity and precipitation and weather - and we can move it on and off as needed.
This is our timeline for hardening off our seedlings:
Days 1-3: Seedlings outside in the sheltered area with a double layer of floating row cover completely covering them. Checking every day to ensure that all seedlings are well watered and doing well
Days 4-5: Move to a single layer of floating row cover
Days 6-7: Remove floating row cover to allow seedlings exposure to full sunlight and ambient moisture and temperatures
If you get a dip in temperatures, either cover up with floating row cover again or move indoors as needed
If you get rain, ensure that your seedlings are either kept out of the rain or moved indoors as needed
Check daily to ensure that seedlings are staying watered, especially during the summer when temperatures start to rise!
Don’t be afraid to recover with floating row cover as needed. It’s better to overcoddle your plants at this stage rather than not give them enough protection - you’ll want to protect your baby plants!
What’s happening as you gradually introduce your seedlings to harsher and harsher conditions is that they will start changing themselves on the cellular level to adapt to the conditions. Those soft, tender, succulent leaves will start building up a thick, waxy cuticle to allow them to better withstand strong winds. The tissues of the plant will start adapting to the colder temperatures, creating molecules to act as a natural antifreeze if they are exposed to freezing temperatures, and they will get tough and strong.
You’ll know that your plants are fully hardened off when they can spend a full day out in the sun without wilting or scorching, but we generally look for thick, sturdy new leaves that are usually a darker green with a more matte appearance.
Transplanting your seedlings
Once your seedlings have been hardened off, you’re ready to get your plants into the ground.
Your beds are prepped, your irrigation has been placed, the soil has been prepped - all that’s left is to get your plants in.
We’ll pick a week of mild weather to plant. In the spring, we’ll usually plant in a week where it will be above freezing for most of the period, while in the summer we’ll try and plant a week where it is not too hot and the weather is fairly nice. Of course this doesn’t always work out perfectly, but so long as it’s not completely miserable to plant out, we do just fine.
We first of all ensure that our seedlings are well watered and the root systems are thoroughly hydrated. Seedlings that aren’t properly hydrated mean that they will have a higher chance of wilting, which means they have a higher chance of having issues getting their root systems to grow into the surrounding soil (the main goal during transplanting) and you’ll have more problems with your plants overall.
We will get ready to transplant by gathering up our seedlings in their cell tray inserts and a chopstick to eject the seedlings from their cells. We’ll also bring along a soil knife or trowel to dig the holes for the transplants.
We’ll pop the seedlings out of their cell insert tray first, and then lay them out on the soil. Be careful to try and keep the root systems as intact as possible - this will help them to transplant more successfully. If we can, we’ll pop out the plug in one cohesive block - this makes for easy handling. Not all of the seedlings will have perfect root systems of course - in that case, you’ll want to gently handle the plant to try and prevent yourself from breaking or smashing the roots.
We’ll dig a hole for the seedling - deep enough to drop the seedling in and keep the first leaves of the plant just at the surface of the soil. Try and position the plant at the level of the soil for the best success.
After dropping the seedling in, we’ll go ahead and pat the soil around the seedling, firming it into the ground to ensure that the plant is firmly in the ground and no air pockets or loose soil are present. That’s all - and we’ll move onto the next seedling!
If we’re planting in cold (freezing) weather for spring blooming flowers, we’ll then cover the seedlings with floating row cover. If we’re planting in hot and sunny summer weather for summer blooming flowers, we’ll also cover with floating row cover. Similar to hardening off your seedlings previously, the floating row cover will ensure that your seedlings have some protection while they get settled in.
The row cover will be supported by the plastic hoop supports to ensure that they are kept up and off the seedlings - this will give them more protection than if they were just lying on the seedlings. We’ll keep the row cover on until the plants are doing just fine without the row cover (for spring bloomers, once the last frost date is past - for summer bloomers, after about a week or two once they’ve started growing roots and are not in danger of wilting so easily).
It’s important that right after you’ve finished transplanting your seedlings that you give them a good watering in. You’ll want to ensure that the roots of your seedlings are fully saturated with water. It will take a few weeks for your seedlings to start putting out new roots that will make their way out into the surrounding soil, so you’ll need to keep them watered in the meantime. Sometimes everyday if you need to.
If you’re using drip irrigation, it’s a simple matter of turning it on to water your seedlings deeply every day. If you’re watering by hand, you’ll want to water thoroughly to ensure that the seed becomes fully saturated and the water gets down to the roots of the seedlings.
Once your seedlings have grown in, you can cut back the watering a bit as they get established. We get to the point where we only water deeply about once a week during the spring, and twice a week during the summer.
Where to grow from here?
Head to the next chapter in this series: How to Start a Beautiful Cut Flower Garden II: Hardy Annuals and Biennials for Spring
Learn more about a special technique of growing the beautiful and much-loved cottage flower garden blooms of spring
And if you’re interested in learning more how to grow flowers as a business - even if it is a small scale business, growing for your own floral designing business or selling to customers, we have an eBook bundle that can offer all the information that you need for starting your flower farming venture
