It happens every spring. The weather hands you a lovely warm and sunny spell, the sap rises up in the gardener in you and you start thinking about planting those tomatoes early, even though your average last frost date is still 3 or 4 weeks away. You peer at the long term forecast and wonder if you should gamble.
Garden centers and nurseries, especially the big box ones, love this season. They can sell you plants now and pretty much guarantee they’ll double their sales when you have to come back and buy another. Here, we call it “blackberry winter” — the near surety that after it gets warm, nature is still going to throw you a late cold spell, usually about the time the blackberries are blooming.
It was 78F here last week; it’s going to snow Friday. Spring is fickle. And the blackberries aren’t blooming yet.
Even if warm weather arrives early and even if you protect seedlings from dying, planting too soon rarely pays off. The weather may be warm, but has the soil warmed up yet? A soil thermometer is one tool every gardener should have. While you can’t ignore the calendar, the soil temperature trumps all. If the soil is too cold, your seeds won’t germinate and your transplants will be stunted, sometimes permanently.
So if you have the itch and you know it’s early, hold off. The sole exception is if it’s something you are succession planting and you have lots of backup plants, where an early crop is a bonus and dead or stunted plants are no loss. Otherwise, be patient. Summer is truly coming, it’s just not here yet.