Technically speaking, we are in a blizzard here in Minnesota as I write this. (There’s not that much snow, but the winds are wicked fierce, which is why I plan to stay off the roads the rest of the day.) But despite the snow (and snow and more snow) this March, gardeners cannot help but turn their thoughts to spring — and planting, especially those luscious early season treats such as lettuce, peas, radishes and spinach.
The lettuces grown by staff are almost ready for the cold frame out behind the MSHS office, but it’s too cold to put them there. With the weather being so erratic the past few years, it’s hard to figure out when is the best time to plant spring vegetables. One method that I’ve been more interested in recently is phenology — or the use of nature signs to decide when to undertake garden chores.
My interest grew from observing a fellow gardener, who always seemed to have the best-looking, most productive peas in the neighborhood. I’ve never had much luck with peas. Either I plant them too early and they rot in the cold soil and never germinate or I plant them too late and they germinate but by the time they are ready to flower and fruit, it’s too hot. My friend waits for the first high-pitched sounds of the spring peepers in the wetland near her house, then she plants her peas.
Gardeners who study phenology rely on signs such as bud break, bird migration and spring wildflower appearances to decide when to plant. For instance, phenology says that the best time to plant lettuce, beets, spinach and other cool-weather crops is when lilacs first leaf out. When the first dandelion blooms, plant potatoes. Wait for the lilacs to be in full bloom before you plant seeds for beans, cucumbers and squash. When irises bloom, it’s safe to plant warm season crops, such as eggplant, melons or tomatoes.
While not exact, phenology gives gardeners a way to moderate the vageries of climate here. (Just for reference, it was 80 degrees F on St. Patrick’s Day in 2012; and barely hit 25 this year.) As gardeners, we need to be observers of our environments — it’s how we see what are plants need and when they are ready for harvest.
Do you use nature signs to manage your garden? Which signs do you use?
—Mary Lahr Schier