Cool nights and cool days bring out both the colors and the fragrances of sweat pea flowers. With all my talk about global warming and impacts on how we garden, it’s obvious we should break from the traditional early April start for sweet pea seeds. Instead, sweet peas should now be started indoors in February.
I am not saying planting in April won’t still produce flowers. It will. However, your sweet peas are going to be bigger, more prolific and earlier-flowering if you start yours in the upcoming weeks instead of waiting for April 1.
There are two reasons this change makes sense. The first is because it really is getting warmer — no matter how cold it is this January. Many nights last summer remained over 55 degrees. And, no one needs to be reminded that we had some awfully warm days. Sweet peas do not do well at 90 degrees.
We know, at least for the foreseeable future, that we will still have cool weather at the start of our growing season. That means we should have these plants in bloom or ready to bloom during that period.
The second reason we should start sweet peas in February — and into early March — is simply because by doing so, we not only get flowers right from transplant, but more. The bonus is we can can pinch back starts during the extra months. This forces the single vine into a branching one and increases the number of flowers produced during the early, cool period.
You are going to need seed. If you can’t find an early rack, this may be one you want to order. My favorite source is reneesgarden.com. She has all the varieties you could want in all the available sweet pea colors. Some are not fragrant. These are beautiful flowers still, but for my money, why would anyone want to grow nonfragrant sweet peas?
Note that there are two kinds of basic sweet peas, uprights and vining. Swallowtail Seeds has 30 different varieties of the climbers. These are vines and they need support.
Roger Parsons Sweet Peas has lots of climbers and uprights. They sell more than 1,300 different sweet pea varieties. You can find a free PDF catalog on their website, rpsweetpeas.com.
I grow sweet peas for my wife, and she likes the fragrant types. Who doesn’t? So, here is a great list of varieties that fit into the good-fragrance category: gardenia.net/guide/most-fragrant-sweet-peas.
To germinate the seed, use a nail clipper or emery board and break through the outer, M&M-like shell to allow water to seep in. Drop into a shallow bowl of water and soak for 24 hours.
Or, you can simply put some seeds on a damp paper towel and put this into a zip-locking bag. Your seeds will swell and germinate. It can take 5 to 14 days depending on temperature.
Once germinated, seeds should be placed in compost or potting soil, one to an individual container, the taller the better. This will promote a good, deep root system. Used, large takeout coffee cups are ideal as long as there is drainage. Don’t forget to label so you know what you are growing.
Since sweet peas are legumes capable of fixing nitrogen, consider inoculating them with nitrogen fixing bacteria, packets of which you can buy from local nurseries. Roll the seed or sprinkle some on each before planting into soil.
Once seedlings have established themselves and put on half a dozen leaves, pinch off the tip down “one leaf.” When the tip regrows, a branch will form. This can be repeated a couple of more times to make a very bushy sweet pea vine.
These seedlings need to be grown cool. If you have a place 45 to 55 degrees where you can supply supplemental light, you will end up with some pretty and definitely early sweat pea flowers.
If you start sweet peas now, you really need supplemental light. However, all of my readers already have them, right? If you don’t, get something, anything to help until April when you won’t need them. You really should break with tradition and you need lights to do it.
Jeff’s garden calendar
Valentine’s at Alaska Botanical Garden: The whole garden will be lit up, with Valentine-themed additions plus hors d’oeuvres, drinks, cocoa, live music and desserts in the greenhouse. Plus there will be a bonfire with s’mores. 6-8 p.m. Friday, Feb. 14. $35 ($25 for members), $12 for children (includes craft), free for 6 and under. alaskabg.org
Local dahlias: Rob Wells, of Hatcher Pass Dahlias, will have tubers and plants available for the 2020 growing season at The Alaska Botanical Garden’s Spring Garden Conference on Feb. 22 and Wednesdays and Saturdays in March at the Midtown Mall Market. Check Facebook for details.