From the ground up: What to look for when buying new seedlings

Transplants shorten the time between planting and harvest

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Plant sales have begun. Garden centers are stocked full of new young plants.

Some vegetables are planted in the garden using small plants (transplants) rather than seeds. This is standard practice with warm-season vegetables like tomatoes, peppers and eggplant and is becoming the practice with cucumbers, squash, cantaloupes and watermelons because transplants shorten the time by several weeks between planting and harvest.

Richard Jauron, horticulturalist from Iowa State Extension and Outreach, answers questions about how to select healthy plants and how and when to plant them in the garden.


Q: What should I look for when purchasing flower and vegetable seedlings?

A: Select short, stocky plants with dark green foliage. Avoid tall, spindly plants. Small to medium-sized transplants become established in the garden more quickly than large ones. Short, stocky vegetable transplants are often more productive than large plants with flowers or fruits. When selecting annual flower and vegetable plants, large transplants are usually not the best choice.

Q: Can I plant flower and vegetable seedlings in the garden immediately after purchase?

A: Annual flower and vegetable plants started indoors or purchased from greenhouses should not be planted directly into the garden. The intense sun and strong winds may damage or kill the tender transplants. Plants should be “hardened” (acclimated to outdoor growing conditions) before transplanting them into the garden. Initially place the plants in a shady, protected location. Then gradually expose the plants to longer periods of direct sun. Closely watch the plants during this period. If possible, check on them at least once or twice a day. Thoroughly water the transplants when the soil surface becomes dry to the touch. Move the plants indoors if strong winds, a severe storm or an overnight frost threatens them. Transplants should be ready to plant after six or seven days of hardening.

Q: What is the proper way to plant flower and vegetable seedlings?

A: Carefully remove plants from plastic cell packs by gently squeezing the bottom on each compartment. Plants in plastic pots can be removed by tipping them on their sides and tapping the bottom of the pots.

If possible, plant annual flowers and vegetables in the garden in the evening or on a cloudy day. Planting at these times lessens transplant stress and allows the plants to recover somewhat before being exposed to the strong, midday sun. Place plants in the ground at the same depth or slightly deeper (no more than 1/2 inch deeper) than they were in their containers. (Tall, leggy tomato plants can be planted much deeper than previously grown as roots will develop all along the buried stems.) Many annuals, such as petunia, snapdragon, salvia and periwinkle, should be pinched back to encourage branching. Others, such as impatiens, are self-branching and don’t require pinching. It’s also advisable to remove flowers on blooming annuals. Blossom removal aids plant establishment. Vegetable transplants should not be pinched.

After planting, water each plant with a dilute fertilizer solution, which can be prepared by adding a small amount of a water soluble fertilizer (such as Miracle-Gro) to 1 gallon of water.

Q: When can I plant vegetable seedlings outdoors?

A: A new extension publication details when to plant vegetables in their gardens called “Planting & Harvesting Times for Garden Vegetables.”

Download a free version online at Planting times listed in the publication are for gardeners in central Iowa. Southern Iowans should plant one week earlier, and northern Iowans should wait a week to begin planting. The publication also lists the last practical date to plant many vegetables.


--- Hummingbirds and Butterflies, 6 to 7 p.m. Wednesday, Marion Public Library, 1095 Sixth Ave., Marion. Master Gardener Jean Murray will discuss butterfly and hummingbird feeding and habitat.

--- Beyond Veggies, 6 to 7 p.m. Wednesday, Earth Source Gardens located at North Scott Boulevard and Rochester Avenue in Iowa City. Jason Grimm of Grimm Family Farm and Scott Koepke of New Pioneer’s Soilmates will present designs they’ve used to grow specialty crops, including grains and beans.

--- Meet Me at the Market, 5 to 6:30 p.m. Thursdays from May through October, NewBo City Market, 1100 Third St. SE. Register at Walk, run or bike.

--- Project Green Garden Fair, 9 to 11:30 a.m. Saturday at Carver Hawkeye Arena, 1 Elliot Dr., Iowa City. Free admission.

--- Benton County Garden Extravaganza, 8 to 11 a.m. May 11, First Lutheran Church, 1523 Sunset Dr., Belle Plaine, $20, Plant and garden art sale from 8 to 9 a.m.; Fairy/Miniature Gardens presentation with Master Gardener Becki Lynch at 9 a.m.; Maximizing Your Garden Enjoyment with Master Gardener Jamie Beyer at 10 a.m.; Gourd Birdhouse Workshop with Master Gardener Tammi Cook at 11 a.m.

--- Raised Bed Gardening Workshop, 9 a.m. to noon Saturday, Prairiewoods, 120 E. Boyson Rd., Hiawatha. Presented by Master Gardener Phil Pfister. This hands-on class will include classroom time as well as time in the Prairiewoods garden preparing a raised bed. $15. Register by Wednesday at

Questions on gardening, land use or local foods? Contact Michelle Kenyon Brown, community ag programs manager at Linn County Extension,

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