Every day the the sun shines brings lots of gardeners to their gardens. The calendar tells us we could be planting early spring crops in the garden but what does the soil thermometer tell us. If you have never thought about the use of the soil thermometer you should! Have you ever had crops that you planted in your garden that just “set” there and did not take off? Perhaps you planted them in wet soils and perhaps you planted them when the soils were just too cold.
Soil temperature plays an important role in seed germination. Adequate soil temperatures for germination range widely for different crops. For example, spinach needs a soil temperature of at least 38 degrees to germinate while lettuces, onions and peas like a 42-43-degree soil temperature. Potatoes do best at 45 degrees, even though legend suggests St. Patrick’s Day is the perfect day for planting our potatoes. And those tomatoes, cucumbers and pumpkins prefer soil temperatures in the 58-60 degree soil temperature range.
So how can you learn about the soil temperature in your garden? You could purchase a soil thermometer. Many garden centers, on-line catalogs and even e-bay has them for sale. Or you could take a minute and check out the CFAES Weather System https://www.oardc.ohio-state.edu/weather1/ . If you scroll down the left column of the page you will see precipitation and soil temperature total, click on the link and for most of us Columbus will be the site you will use. You will then see the charts populate with precipitation and soil temperature data..
Maybe you even want to check out the OSU https://agcrops.osu.edu/newsletter/corn-newsletter/2020-09/cfaes-ag-weather-system-near-surface-air-and-soil. In this week’s CORN newsletter it was reported that soil temperatures have reached into the 50s south of I-70 and mainly 40-50's to the north. Soil temperatures will rise a bit more this week but will slow by late week into mid April as cooler weather moves in.
These handy tools are just one click away. Start your growing season off right. Check soil temperatures before opening your first packet of seeds to plant in your garden.
Source: Connie Smith, Master Gardener Coordinator-Fairfield County