How to Grow Snapdragons (Chantilly, Potomac and Rocket)
Snapdragons aren’t necessarily one of the flowers that I first fell in love with as a grower. They were kind of “meh.” I thought of them as mostly bedraggled bedding plants that never really looked great at any point, although I was fascinated by the small snapdragon that managed to struggle and overwinter three years in a row.
In addition, snapdragons were endemic in all of the very standard Teleflora designs, especially in the “Hospital Dolly Yellow” as Sarah Raven describes it. Boring, standard, and overused, there was nothing that I loved about snapdragons.
That was, until I saw some photos of snapdragons in farmers fields. We don’t have too many of those vertical spires available to us - digitalis, veronicas, verbascums, eremerus are the only ones aside from snapdragons I can think of. A row of snapdragons standing upright at attention is something to behold.
In addition, I was seeing more of the unusual varieties - the open faced Chantilly, the ruffly azalea-flowering Madame Butterflies, the short explosion of petals with the Twinny series, the soft bicolored appleblossom coloration.
What I didn’t know however, was just how productive snapdragons are. When we grew them last year, I was very excited to cut them at first. And then I cut them again. And cut them again all the way into November. I’m also pretty sure that if we hadn’t moved, we would have a whole row of overwintered snapdragons ready to go this spring as well.
As a grower, it’s very important to have crops that are pretty and unique and top sellers. But it’s also important to have crops that will be reliably productive for when you need to fill bouquets or just need flowers available. Snapdragons are one of those flowers.
Having a row of snapdragons is easily one of the best investments that a flower grower can make! They are also relatively easy to grow once you have a couple key concepts down.
1. Pick your snapdragons variety
Snapdragons are one of those weird flowers that are incredibly predictable. Like terrier dogs bred for vermin extermination or draft horses bred for plowing a field or Polish chickens bred for their fluffy feathers, snapdragons have been bred to flower in four different groups in the season based off of light intensity, temperature, and day length. They were selected for controlled greenhouse production, but do very well in the field with a little planning.
Group 1 - Chantilly, Legend, Maryland
Group 2 - Animation, Costa, Overture, Maryland,
Group 3 - Potomac, Opus, Madame Butterfly
Group 4 - Opus, Rocket, Madame Butterfly
There are what are known as Group 1 and Group 2 - these bloom best in the spring, when temperatures are cooler and days are shorter and light is softer, while Group 3 and Group 4 bloom best during the hotter, longer days of summer with high light.
Here in New Mexico, we usually only get a short burst of useable blooms from Groups 1 and 2, mainly the Chantilly. After around mid-June, the flowers get teeny-tiny and stop producing the way they do in the spring. If we don’t need the space, we would cut back the stems and let them come back for a nice fall bloom, but usually we’ll be done with them after late spring.
On the other hand, we will plant Madame Butterfly, Opus, Potomac and Rocket for cutting all summer long - these are the ones that will pump out blooms, sometimes up ten stems to a plant at a time. Their consistency and excellent performance in the heat means we can rely on them when flowers from others are slow (such as during a succession or before/after their season ends)
As far as colors, we stick to bronze (an orange/peachy/salmony coloration) dark red, white and the bicolor appleblossom (white with pink)
2. Buy the correct seed
Good snapdragon seed is rather expensive - that is, the ones meant for cutting are expensive relative to bedding or ornamental ones. Which, to be fair, are well worth the money. You can buy excellent snapdragon seed from Johnny’s, which have some of the highest germination. I have good experience buying seed from Geo, but you can also try Ivy Garth, Ball America, Harris, Floret and The Gardener’s Workshop.
3. Scheduling: Plan well ahead!
Snapdragons take a long time to grow. We wanted white snapdragons for a May wedding last year, and everything was going fine until I realized we weren’t going to have snapdragons until July.
Most of the snapdragons are 120 days to maturity, although Group 1 like Chantilly are a mere 100 days. 100 days may not seem like much at first, but that’s over three months - ¼ of the year, with 120 days being ⅓ of the year. If you want to have snapdragons, make sure to start them early (i.e. start ‘em now!)
Snapdragons have very small black seed - they’re almost as bad as poppies to be honest! I use a moistened toothpick to transfer them to their designated spot (a little trick I learned from Lisa Mason Ziegler!). We grow them in the mini soil-blocks, so transfer the seeds onto the top of the soil block, usually in the depression.
Snapdragons like a relatively warm space (70 F) and a little bit of light (indirect light from a window or direct light from a shop light). The seeds will start to pop up here in about 7 days, after which you will want to get under light ASAP before they start getting leggy.
You can grow snapdragons warm or cool - they’ll develop a bit quicker when warm, but you also run the risk of potentially drying them out faster, so proceed with caution. I haven’t had issues with damping off or pathology when grown in standard clean conditions, but it is important to keep humidity high (using a dome in my case) to ensure that the seedlings pop off their seed capsule (it can get stuck if the humidity is too low).
6. Growing them out
No major issues here for growing them out - I make sure to give them a good feeding of fish emulsion via bottom watering of the mini soil blocks. At this point it’s mostly just waiting for them to get a couple sets of true leaves on them.
7. Planting out
Snaps can be planted out pretty tiny - the mini block should be more than enough root structure to get them transplanted. Generally, we’ll go out to the row and use either a butter knife or a finger to make a depression into the soil, then transplant the little snapdragon. We water in well, give a spray of kelp and fish emulsion, and let them take off.
Snapdragons can be planted out in relatively cold weather - they enjoy a good long cool establishment to build up their root structure prior to putting on more top growth, and will give you bigger, taller, better blooms. Fall planted is best, but late winter/early spring will still give you good blooms.
The transplants may look tiny now, but don’t worry - they will get plenty big and bushy by the time summer hits.
Your snapdragons will get bigger and bushier, and then will start growing vertically when they form a flower stalk. For a really nice big central flower, you can wait until it forms OR you can pinch initially to get multiple smaller but still very nice side blooms.
Regardless, when you harvest snapdragons make sure to cut down as low as you can go, all the way to the base. If you cut halfway through the stem, you’re going to just end up having a weirdly-forked stem with multiple little heads on top. Instead, cutting down at the base of the plant will encourage it to send out nice long side branches. It sounds counterintuitive, I know, but believe me that it will work!
Cut when ⅓ to ½ of the lower flowers have opened, but the top flowers are still in bud. After cutting you can go back in and give a good feed of fish emulsion and kelp to encourage regrowth.
We don’t treat our snapdragons with any special postharvest procedure - just lots of cool water and let them rest in a cool dark area. Make sure to keep them standing upright, as they are geotrophic and will curve upwards if laid at an angle in a bucket.
9. Overwintering/Fall planting
If you live in a strange environment like ours, with little winter moisture, warm temperatures, and what amounts to basically sand for substrate, you can overwinter your snapdragons for bloom next year. While it’s not guaranteed, they can act as perennials in the warmer areas of the country.
Alternatively, snapdragons also do very well when fall planted. You might even get a few blooms off them before they settle in for the winter, given that they are so hardy. I especially recommend you try Chantilly and other Group 1 snaps for fall planting to take advantage of the full cool growing season.
I hope you give snapdragons a try! Whether as a home gardener or a grower, they are a wonderful bloom to have for pretty much the entire summer and such a great addition to designs and bouquets.