Growing Snapdragons

I've written a few times about our production process growing cut flowers for florists but have never highlighted Snapdragons. It's about time :) They were our featured flower in The Flower Farmers book from bloom.imprint by Debra Prinzing & Robin Avni, so they definitely deserve their own post.

Environment:

While snapdragons can tolerate a light frost, our goal is a high quality cut flower for our florists, so we do everything possible to give them their ideal growing conditions instead of pushing them to their limits. North Texas is generally zone 8 which means, on average, we don't have very many freezes but in February we're normally hit with some pretty extreme ice-events or cold plunges. Our aim is a nice March harvest just in time for wedding season and those extreme events would really stress our almost-mature snapdragon plants. Growing them in our unheated high tunnel is a must. On rare occasion, if the temperatures fall below 20F, we'll run a propane heater in our tunnel overnight. Often our fancy butterfly-ranunculus are also on the cusp of maturity and we really need them babied right before their spring debut.

It's very possible to grow snapdragons outdoors, protected by frost cloth, but I would time them for a later bloom (April) so the plants are smaller when the February cold hits - the plant can handle cold temperatures better if it's established but smaller.

Variety:

I only grow Group 1 & 2 snapdragons. They are bred to be grown under low light conditions and short day-lengths, which is exactly what we have here in Dallas from November to February. I have grown group 3 & 4 timed to bloom in May, the difficulty is that my high tunnel heats up so fast come mid-March that they're often stressed with aphids that late in the Spring season and the quality is greatly diminished. If I grow them outside for a May harvest, I would need to transplant around February when the nasty weather rolls in. The timing just doesn't work out. Because we sell to florists, and snapdragons are easy to find from the wholesaler, a sub-par crop isn't worth the hassle. If we want to command a nice price, we have to have a high quality product. The group 1 & 2 grows slowly over the winter and, protected from the extremes of weather, often grows to 4 feet, sometimes higher, giving us a really nice long cut for our florists.

Timing:

I sow snapdragon seeds in soil blocks (or seed trays) anytime in September. Some years it's 9/1, sometimes it's 9/25, but I usually aim to have them sown by October 1st. After they've germinated under lights in my warm grow room, I take off the humidity dome and move them to my floral cooler - which is set to 60/65F. There, they grow under lights in cool conditions that they love until they're ready for transplant (or until the weather outside is ready!). They usually spend about 2 weeks in the warm room and 4-6 weeks in the cooler room until I transplant them out when the weather is reliably below 85F. This can be anywhere from mid-October to mid-November, occasionally later if the hot weather is just being stubborn. If the seedlings are looking really stressed in the tray but the weather is still hot, I'll bump them up (repot them into a bigger tray or soil block). I have found that hot weather is far more stressful for them than sitting in the tray a bit long, so I always wait to transplant until ideal conditions. Then they sit and grow strong roots and slowly node-by-node grow until the warmth of March when they literally shoot up and begin to bloom.

Using the netting to space snapdragons - two per square - roughly 3" apart.

Pinching/Spacing/Netting:

I don't pinch my snapdragons. Pinching would delay the blooms and I want them blooming in time for wedding season and before the heat hits. Because of this, I space them roughly 3" apart and get a nice tall, thick stem for cutting. This also requires netting for support. My clay soil makes it tough to pound in a stake, so instead I use fiberglass rods and pound them in using a rubber mallet. I wait and net my snapdragons when they're about 2 feet tall - the calcium sprays and lack of weather pressure means they usually grow pretty straight for a while. When the heavy bloom arrives, this is when they'll need the support structure to keep from toppling over. Once the netting is up, as they grow each foot, I simply yank the netting higher (a bit unceremoniously, lol). That way, I don't have to mess with two layers of netting, which would be expensive and time consuming. This also means the netting is high enough where I won't be in danger of cutting it when I harvest low on the stem.

Fertility:

We have clay soil and over the summer it can get pretty compact. I also use a broadfork to loosen it and spread an inch or two of compost before transplanting. I've found that snapdragons aren't as fussy about compact soil like some plants. When January arrives, we usually have a bit of warmth where they put on a lot of growth quickly and it's important to give them calcium during this period to strengthen the cell walls. If you see stems splitting down the center, it's a sign of a calcium deficiency due to fast/sudden growth. At the beginning of March, I give them another dose of calcium and some compost tea. I avoid giving them nitrogen because I want to encourage blooms, not more stem growth. It can be hard to find calcium without nitrogen, so I make my own following Bare Mtn Farms process for soaking charred bones in vinegar.

Harvest:

Usually, the plant starts budding up at the end of February and I start getting my first nice cuts around March 15th. Then I cut for roughly 4-5 weeks straight until the heat really sets in. I don't usually mess with the secondary flushes (except for friends and family) because the quality can't compete with the wholesaler but if it's a particularly cool April and the secondary cut is quality, it'll be a bonus crop. I don't count on it though. The harvest has to be worth the cost of water to irrigate and the labor spent harvesting to warrant the effort. Usually, the plants are pulled by the end of April and a cover crop gets sown. My friend, Amber, lives outside of the urban heat bubble and her snapdragons last until Mother's Day with very high quality. I am jealous, but my environment just doesn't cooperate :) The flowers are geotropic, which means they curve with the earth's gravitational pull, so when we harvest, we bunch with a rubber band high up on the stems and a second one at the end of the stems to keep them straight then set them in the tallest possible bucket we have (a 5 gallon one). The bucket in the picture is not what we use, haha, that's for aesthetic purposes. A bucket with straight sides is best.

*I am a strong believer that most flower flowers harvest their snapdragons too early. The conventional wisdom is to cut them when the bottom 2-3 flowers are open. This is necessary if you have to store the flower for several weeks. However, our blooms go straight to the florist which usually uses them within the week - and usually in a wedding. In that time frame, the snapdragon would never open to its full, fluffy potential if we cut them tight. We realized that by harvesting when there's at least 4-5 blooms open and roughly 4 at the top still to open, we can command a much higher price with the florists, because they're getting a much more robust bloom. If necessary, we strip off a few of the lower flowers that are getting old, but the snapdragon will still keep at least a week and then bloom for another week and look far more amazing than the half-closed version we used to sell. Our florists LOVE them this way.

Snapdragons are one of our most reliable crops when it comes to growth and profit. With affordable seed that are easy to germinate, we can basically plant and forget about them except for a few weeks of fussing in February. We never have difficulty selling them at a good price and this earns them a spot on our tiny urban farm every single season.

Happy growing!

sarah jo