Here are some general guidelines on setting your transplants into the garden.
- Harden off plants. Be sure to harden off indoor- or greenhouse-grown transplants before planting in the garden. This should be done over the course of a week or two. On the first day, place plants outdoors in a sheltered spot for an hour or two. Choose a location in light shade and protected from strong winds. The next day, increase the amount of time and exposure slightly, and continue to increase every day until you are leaving the plants out in full sun and overnight.
- Transplant on a cloudy day. Avoid transplanting during a heat wave; intense sun can harm newly planted transplants. If you must plant on a sunny day, wait until evening.
- Don’t crowd plants. Remember that those small transplants will get much larger over the course of the summer! Overcrowded plants are more susceptible to disease problems, and will be less productive than properly spaced plants.
- Prepare the garden soil. Loosen soil to a depth of at least 12 inches, and mix in some organic matter such as compost or aged manure.
- Work quickly. The less time the transplants’ rootballs are left exposed, the better. Have everything you need at hand before you remove the plants from their pots.
- Wait until the proper planting time. Cool-season crops like broccoli and cabbage can be set out a week or two before the average last frost date. Tomatoes, peppers, and eggplant, on the other hand, are heat-loving plants, so wait until after your average last frost date to move transplants into the garden, and be prepared to cover plants with fabric or plastic if a cold snap threatens.
Following is a step by step guide to transplanting tomatoes. These guidelines can be used for any plant, with one exception: All plants other than tomatoes should be set in the ground at the same depth that they were growing in the container. Begin by soaking the rootball in a dilute fertilizer solution. Set the pots in a waterproof tray, and pour in a half-strength, lukewarm solution of fertilizer (preferably fish emulsion- or seaweed-based) to a depth of about one inch. The moisture will help keep the rootball intact, and the fertilizer will get the plants off to a good start. Let the plants soak for at least half an hour, while you assemble your materials and prepare the planting area. Next, dig the planting holes. It’s a good idea to use a yardstick or measuring tape to be sure you’re spacing plants properly. Avoid the temptation to squeeze in a few extra plants. Pour some water into the planting holes to moisten the soil. Remove a plant from its container by placing one hand over the soil surface, so that the plant is positioned between your thumb and fingers. Turn the pot upside down, and rap gently on the bottom of the container. Hopefully, the root ball will slide right out. If it doesnt, try squeezing the container, rapping harder on the bottom, or, as a last resort, cutting away the container. If the plant is growing in a peat pot, there’s no need to remove the pot. However, it’s a good idea to tear away the top rim of the peat pot down to the soil line. If the peat pot is exposed to air, it can wick moisture away from the root ball. Set the plant in the hole, and add soil around the rootball, gently firming the soil as you go to eliminate air pockets. Once the hole is filled, create a shallow well around the plant, so that water will gather there instead of immediately running off. Protect new transplants against cutworms. These common pests chew young stems right at ground level. One easy method is to loosely wrap a strip of newspaper around the stems. The paper should span from one to two inches above the soil surface to an inch or two below—this is the cutworm’s territory. A collar made from several thicknesses of newspaper will last long enough for the stems to grow large enough to discourage cutworms. Don’t wrap collars too tightly, and don’t use plastic. Water the plants gently but thoroughly. You’ll need to check the plants frequently, and water as necessary to keep soil moist down to the depth of the rootball.
Tomatoes are one of the few plants that can—and should—be planted deeper than their original soil line. Unlike most plants, tomatoes will develop roots along their buried stems. These additional roots will help anchor the large plants and will allow the plant to take in the nutrients and water it needs to product a good crop. If you have a stocky, compact plant, bury the stem up to the first leaf. If your plants are tall and leggy, pinch off the bottom few leaves, then set the plant sideways into a trench, carefully bending the top of the plant upward.
Credit: National Gardening Association