Get a garden thermometer to start the season right
Q. Someone mentioned I should measure my soil temperature before planting my vegetable garden. Why would I do that?
A. Ever tried putting your toes in Lake Michigan in the early part of May? Oohhhh baby, it's COLD!!
Well don't do the same to your tender spring transplants and seeds. Why put those tender roots and seeds into cold, wet, chilling soil? Plant your seeds and transplants in the right soil temperature.
Planting in too cool soil can cause seeds and plants to rot or not grow at all. Soil temperatures are extremely important for seeds to germinate and getting roots to grow on transplants. You want your seeds and plants to be comfortable so they will take off running, or rather germinating, within their recommended number of days. This is another step in having a successful garden this season.
Do you have one of the most important garden tools in your tool bucket, a soil thermometer? Measuring the temperature of the soil is a much more accurate measure of when to plant than the temperature of the air or the "average frost-free date" calculation (May 15 in the Chicago area).
Now don't just run out there with the thermometer you just used! You do, however, need a metal thermometer you can purchase at a garden supply store, hardware or auto shop. Go dial or digital; just go get one! Now get out there with your new garden "toy."
Check the time. The best time of day to measure soil is between 10 and 11 a.m. The lowest soil temps register right after dawn and the warmest temp is mid afternoon (3 p.m.). Therefore, late morning is the best time. Insert your thermometer 2 to 4 inches into the soil. Record a couple of days' readings for a consistent number.
Oh, you said you had a job and are not home at 10 a.m. Simply take the soil temp before you leave for work and again when you get home. Add the morning and early evening temperatures together and divide by two, and do this for at least four days to get a consistent reading.
The earliest plants - spinach, onions, potatoes and lettuce - can be planted at 35 degrees. Forty degree soil will work the best for turnips, peas, radishes, Swiss chard, carrots, cauliflower, cabbage, and beets. Fifty degrees is the time to plant tomatoes and corn. AND if you wait until 60 degrees, you can get your beans, pumpkin, squash, eggplant, peppers and cucumbers safely nestled into the ground.
Don't be intimidated by your neighbor bragging: "I put my garden in on May 1."… RESIST and do the right thing. Get that soil thermometer out, measure temps and do the best thing for your seeds and transplants. Plant when the temps are right!
- Bev Krams
• Provided by Master Gardeners through the Master Gardener Answer Desk, Friendship Park Conservatory, Des Plaines, and University of Illinois Extension, North Cook Branch Office, Arlington Heights. Call (847) 298-3502 on Wednesdays or email northcookmg@gmail.com. Visit web.extension.illinois.edu/mg.