SunflowerMay is transplant month: the time to set out small vegetable and flower plants with the hopes that by the end of summer, you’ll have a bountiful crop of tomatoes and marigolds.

Transplants make it easy for the gardener to obtain plants that might be difficult to raise. For example, petunia seeds are so small that a light breeze can blow them out of your hand. Getting them to germinate is difficult indoors, let alone direct seeding them outdoors.

In fact, any direct seeded plant will do better than most transplants. It just may be impossible to direct seed many plants.

Of course, transplants also provide the uniformity that gardeners need. A row of marigolds will be the same height and color when you buy them; that means they’ll also look similar in the yard.

Not everything is grown by transplant. You can’t find sunflower transplants on the market. Who really would want, or need, to plant one that way? While you can find cucumber, watermelon, cantaloupe, squash and pumpkin transplants, it really is better to plant those seeds directly in the ground.

There are five recognized characteristics that transplants should have:

  • Typical green color. Now, this doesn’t mean dark green. Not all plants have dark green leaves. Petunias, for example, have lime-green foliage. Marigolds have a forest-green color. A dark green color may indicate too much fertilizer.
  • A short, compact plant. “Stocky” is the term that comes to mind. Plants should not be tall and leggy. Bigger definitely isn’t better when dealing with transplants. A stocky plant indicates correct growing conditions, usually on the cool and sunny side. Stocky plants adapt to the garden quicker and are less likely to be damaged by winds.
  • No insects or diseases present. Check the plants carefully. Look under the leaves, on the stems, and in the soil for insects. Inspect the leaves for disease spots. There’s no need to introduce problems into your garden.
  • Roots should be plentiful and white. Avoid plants, if possible, with lots of roots coming out of the bottom of the pot. There’s seldom any way to remove the plant without cutting off these roots. Lift the plant carefully out of the pot. You should see lots of white roots. There should be some resistance to your careful tugging on the plant. If the plant comes quickly out of the pot, chances are the soil has dried repeatedly, causing some root injury. Make sure to look for insects or diseases on the roots.
  • No flowers, flower buds or fruits. This is the tough one. Who would buy a flower without knowing what color the flowers will be? Sure, you can almost trust the signs, but who’s to say that little Tommy or Mary didn’t pick up a plant, and then put it back some place different. I wouldn’t buy any flower without seeing what color the blooms are, especially if you want a solid bed of white geraniums. A couple red or pink ones would spoil the effect.

Flowers, flower buds and fruits forming on the vegetable plants take the primary energy from the plant. The goal with transplanting is to encourage root and shoot growth. If the plant is blooming and producing something edible, roots will suffer.

Vegetable transplants shouldn’t have any fruit on them. You won’t be able to tell colors or size by a small vegetable.

For all other transplants, it’s a good idea to remove the flowers and flower buds when transplanting. There’s no doubt that this is hard to do, but it is necessary for the plants to produce good flowers and vegetables throughout the summer.

University of Illinois Extension Educator David Robson wrote the yard and garden column for more than 30 years until his retirement in 2017.