A week ago, two large flocks of redwing blackbirds ascended in the treetops at the edge of our marsh — a sure sign that winter is over ... for me, at least.
Winter may not be giving up without a fight, but those of us who work with plants know that spring has already arrived. Plants have begun responding to the increase in daylight hours. You may have noticed your houseplants have once again started putting on new growth.
It may be in the single digits when I walk outside tomorrow morning, but if the sun is out, it will be a balmy 70 degrees inside my greenhouse by 10 o’clock.
Some of my greenhouses are heated all winter; others are cold storage houses for plants that need a little protection but can tolerate temperatures dropping below freezing without being killed. Even inside an unheated greenhouse, temperatures this time of year will rise well into the 70s on a sunny day but drop back around freezing at night.
One of the things I’m doing inside my unheated greenhouse is starting seeds for one of my favorite spring plants, fragrant sweet pea.
It may seem early to be thinking about planting blooming crops, but sweet peas thrive in very cool conditions. I have successfully planted sweet pea seed straight into the garden later in the spring, but more often than not my soil still retains too much moisture in mid-march to early April when sweet peas should be planted in the ground here in my zone 6 garden. They can tolerate the cold temperatures of early spring, but they need good drainage to prevent the seeds from rotting.
My solution the past few years has been to plant the seed in 4-inch pots and store them in an unheated greenhouse. They take about two weeks to germinate, and although temperatures at night can drop down near freezing, they don’t seem to mind at all. In fact, they seem to love it!
Before I plant the seed, I soak it overnight in water to help soften the seed’s hard outer shell. Once the seed has germinated and the vines have produced a few leaves I pinch them back to encourage branching which will produce many more flowers once the vines begin to bloom.
In the cool temperatures of my “walk-in cold frame” the sweet pea seedlings produce firm, compact growth not possible on the windowsill of a warm kitchen window — a mistake many gardeners make when attempting to grow sweet peas for the first time.
I feed the young plants a few times with water-soluble fertilizer to promote strong growth, and once my garden soil is workable, sometime in April, I transplant the seedlings into beds along the fence of my vegetable garden. The fence provides support for the vigorous vines while they climb, and cutting the fragrant blooms is easily accomplished from either side of the fence. Their incredible perfume entices me to spend as much time in the vegetable garden as possible.
Planting sweet peas early gives them the 60 or so days of temperatures below 60 that they need to thrive and produce a good crop of flowers. Sweet peas hate hot weather, and once it arrives, the show is over. By the 4th of July, sweet peas have pretty much finished, unless it stays unseasonably cool.
It may still be cold outside, but I’m going to make the most of it — and in a few months, when I am picking a bouquet of fragrant sweet peas, I’ll be glad I did.