It’s officially spring and, with warmer weather on the way, some Cincinnati gardeners may be itching to get outside and plant.
But, not so fast. According to the Old Farmer’s Almanac, most seeds shouldn’t be planted or transplanted outdoors in Greater Cincinnati until late April, or after the threat of the last frost has passed.
So, when was the last frost? And how important is Ohio’s plant hardiness zone? For a more detailed look at when to plant what, we answered some of the most-searched springtime gardening questions in Ohio.
Find the answers below, and happy planting.
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When was the last frost in Ohio?
On average, the last spring frost in Greater Cincinnati was on April 23, according to the Almanac. In Columbus, it’s April 27 and in Cleveland it’s April 14.
Enter your location on the Almanac’s frost date guide at almanac.com to find the last frost in your area.
What plant hardiness zone is Ohio?
Most of Ohio falls under plant hardiness zone 6a, according to the United States Department of Agriculture. Some areas are listed as zones 6b and 5b.
Plant hardiness zones can help determine whether a plant will thrive in your climate. Check your zone against the zone listed in a plant’s care card. Zones are based on the average annual minimum temperature in winter, as recorded by the National Oceanic and Atmospheric Administration.
Use the USDA’s interactive map at planthardiness.ars.usda.gov to find your area’s plant hardiness zone.
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When to plant tomatoes, other crops in Ohio
Tomatoes should be planted after the last frost, according to The Ohio State University’s College of Food, Agricultural and Environmental Sciences. In Central Ohio, the ideal planting time is around May 20. In Southern Ohio, it’s one to two weeks earlier, and in Northern Ohio, it’s one week later.
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For when to plant other crops, check the Almanac’s 2023 planting calendar at almanac.com.
When to plant hydrangeas in Ohio
Hydrangeas should be planted in late spring, well after the last frost, or in early fall, at least six weeks prior to the first frost, according to HGTV. The first fall frost in Cincinnati is Oct. 20.
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When to fertilize lawn in Ohio
Lawn fertilizers should be applied as needed three times per year: late spring, late summer and late fall, according to Ohio State University associate professor Mike Hogan. Spring is also the best time to tackle crabgrass and other lawn weeds.
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For reseeding empty lawn patches, OSU Extension recommends waiting until fall.