March 29 – April 4
Soil Temperature Controls Planting
We don’t plant our vegetables against a date. We put our plants out only when the soil temperature is right for each species of vegetable. If we put out a tomato when the soil temp is ten degrees too cold, that tomato will never produce well no matter what we do to try to keep it happy for the rest of the season. We can’t cheat on soil temperature. If we do we cause stress in our vegetables that is never completely eased during the whole season.
We all need a digital soil thermometer. Google “digital soil thermometer” and you’ll find a dozen to choose from. Mine cost $22 and it’s worked well now for five years. In early spring I carry my soil thermometer every time I go out in the garden. No seeds and no seedlings should go into the soil before the soil temp is 40 degrees or higher. You measure down about two inches.
When the soil hits 40 then you can plant seeds for peas, spinach, Swiss chard, beets, and leaf lettuce. You must wait maybe three or four weeks until the soil temp hits 60 before putting out any cold weather seedlings like cabbage, broccoli, kohlrabi and cauliflower. Wait a few more weeks to plant seed for green beans and cucumbers when the temp is 65, not any earlier.
The big mistake is made when putting the warm weather seedlings into the garden. Tomatoes, sweet peppers, and summer squash should definitely not go out into the soil until it hits 70 degrees. If you really like tomatoes, you wait until it hits 75 degrees; that five degrees makes a difference. I predict our soil temps do not hit 70 much before the second week in June.
On March 24th of week 13 our soil temperature was 39°F while the air temperature was 45°.
Predicted last frost around May 15th or Week 20; seven more weeks.
Nature’s schedule this week
The miniature crocus should start blooming. Unfortunately the poison ivy starts leafing out. The mourning cloak butterflies come out of hibernation on days that are warm. Those cute salamanders return to the ponds to mate and lay eggs. The bluebirds will be returning so it is time to put out a bluebird nesting box. For you birdwatchers the eastern towhee returns.