From the Ground Up: May is a magical month for gardeners

But don't be tempted to plant before the frost date

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Gardeners have many questions right now. When do I plant? What can I plant and when are we going to have warmer temperatures?

Here, Linn County Master Gardener Judy Stevens attempts to answer these questions and others.

Q: What can I plant in May?

A: May is the magical month when all gardeners have visions of creating Monet’s gardens, but sometimes Iowa’s weather doesn’t cooperate. The garden centers are full of the latest and greatest plants available and we ponder whether we should try plants suitable for zone 6 when we know that our garden has not always supported plants suitable for zone 5. Beware of temptations and follow these planting guidelines.

Q: When can I plant impatiens, coleus, and begonias?

A: Iowa State Extension suggests the last frost date is about May 10, but the old Czech and German tale states that the three frozen kings will come on the 11th, 12th, and 13th of May, so be safe and do not plant any of the tender annuals until May 15. It’s also a good idea to have towels or sheets available to cover the tender annuals should our fickle weather decide to bring us a late frost.

Q: Can any annuals be planted before the last frost date?

A: Pansy’s and snap dragons are excellent choices for early planting, but may need to be replanted or inter-planted with heat loving annuals, since both, especially the pansy’s do not do well in the extreme heat of July and August.

Q: When can I plant tomatoes, eggplant, snap beans, melons, squash and pumpkins?

A: These vegetables are considered hot weather vegetables and should not be planted until well after the frost date since they prefer soil temperatures of 55 degrees or more.

Q: Can any vegetable be planted before the last frost?

A: Some vegetables are considered cool weather veggies and actually prefer cooler temperatures. Lettuce, cabbage, kale, peas, spinach and radishes are cool weather lovers which can be planted in early spring or again in August to take advantage of the cool fall weather.

Q: What about root crops like beets and carrots?

A: Beets and carrot seeds can be directly planted in the spring before the last frost and can even be sown every two to three weeks for beets and every three to four weeks for carrots for a continuous harvest through the summer.

Q: What about melons such as muskmelon and watermelon?

A: Seed melons in mid-May after soil temperatures warm. Check your seed packets to determine varietal differences in the length of time from planting to harvest. The last practical date to sow seeds of early maturing varieties is June 20.

Q: When can I move my houseplants outdoors?

A: When all danger of frost is over, you may put your houseplants in a shady area. The outdoor sunlight can sunburn your plants in a few short hours so be careful to place them in the shade. Even in the shade you may want to cover the plant with a sheet for half of the day to protect the plant. Even cactus plants can be sunburned after they have been inside all winter.


--- Heavenly Hydrangeas, 6 to 7 p.m. Wednesday at Marion Public Library, 1095 Sixth Ave., Marion. Master Gardener Wil Carew will discuss planting, pruning and more.

--- Raised Bed/Square Foot Gardens, 6:30 to 7:30 p.m. Thursday at Ely Public Library, 1595 Dows St., Ely. Master Gardener Wil Carew will discuss the benefits of raised beds, examples of beds, construction techniques, trellis/cloche use, and protecting crops from animals.

--- Backyard Chickens, 7 p.m. Thursday at Indian Creek Nature Center, 6665 Otis Rd. SE, Cedar Rapids. Learn basic information to raise hens in urban and suburban areas. Participants will receive a certificate of completion that enables them to get a permit to legally keep chickens in Cedar Rapids. Register by 4 p.m. Wednesday at (319) 362-0664 or

--- Annual Spring Plant Sale, 9 a.m. to noon May 4 at Indian Creek Nature Center, 6665 Otis Rd. SE, Cedar Rapids. Find everything you need to create beautiful gardens — native prairie and woodland wildflowers, traditional garden flowers, hostas and more. Vendors offer vegetable and herb seedlings, yard art, willow towers and trellises. Free admission.

--- Bunny Basics, 1 p.m. Saturday at Indian Creek Nature Center, 6665 Otis Rd. SE, Cedar Rapids. Visitors may have seen Toby hopping around or hanging out in his cage at the center since February, but now he’s ready to make his first official appearance. Learn about mammal traits and discover interesting facts about rabbits, both domestic and wild. For children aged 4 to 8 accompanied by an adult. Cost is $5 to $6 for children, adults are free. Register at (319) 362-0664 or

--- Herb Day, 1 to 4 p.m. Saturday at the Robert A. Lee Community Recreation Center, 220 South Gilbert St., Iowa City. Join Iowa City herbalist Stephany Hoffelt and her students as they explain ways herbs can enhance lives. Activities will include presentations, an informal herb walk through urban gardens to explain the traditional medicinal uses of some of the herbs planted in the gardens by Backyard Abundance, information table, refreshments, and door prizes.

Have a gardening question? Send it to Michelle Kenyon Brown, community ag programs manager at Linn County Extension, at

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