April 21, 2020 - 3:29pm -- smith.3204@osu.edu

Sunny days no doubt bring lots of gardeners out into the sunshine.  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 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 thru April 10, 2020

Maybe you even want to check out this week’s CORN newsletter where it was reported https://agcrops.osu.edu/newsletter/corn-newsletter/2020-09/cfaes-ag-weather-system-near-surface-air-and-soil that soil temperatures warms as the air temperature continues to warm as a more typical April weather pattern begins to surface.  

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.  Happy Gardening!!!

Source:  Connie Smith, Program Assistant, Master Gardener Coordinator-Fairfield County