When Is It Safe To Plant Summer Annuals?

When Is It Safe To Plant Summer Annuals?

“When is it safe to plant summer annuals? Should I wait until after Mother’s Day to plant my marigolds, petunias, and other annuals?  I live in Central Ohio.” Question from Diane of Newark, Ohio

Answer: Always plant warm-season annuals, like petunias and marigolds, after the threat of frost has passed. To do this, you need to know your last frost date. The Old Farmer’s Almanac provides this data. Every gardener should know both their first and last frost dates for the growing season. Here is the data that is yielded when I search using your Zipcode:


Nearest Climate Station Altitude Last Spring Frost First Fall Frost Growing Season
NEWARK WATER WKS, OH 836′ May 4 Oct 6 154 days


To be safe, I always plant at least a week after my last frost date–especially if the weather has been temperamental. When planting your flowers, be sure to feed them with a fertilizer formulated for flowering plants, such as Proven Winners® Continuous Release Plant Food, and amend the soil with Black Gold Garden Compost Blend or Canadian Sphagnum Peat Moss to improve its structure and fertility

Happy gardening,

Jessie Keith

Black Gold Horticulturist


Plants are the lens Jessie views the world through because they’re all-sustaining. (“They feed, clothe, house and heal us. They produce the air we breathe and even make us smell pretty.”) She’s a garden writer and photographer with degrees in both horticulture and plant biology from Purdue and Michigan State Universities. Her degrees were bolstered by internships at Longwood Gardens and the American Horticultural Society. She has since worked for many horticultural institutions and companies and now manages communications for Sun Gro Horticulture, the parent company of Black Gold. Her joy is sharing all things green and lovely with her two daughters.

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