How to Transplant Starts

You started a whole gaggle of seeds indoors, happily sprouting under the warm glow of electric grow lights, and now it’s time to move your babies into the garden. But what can you do to insure that these sensitive, fragile little guys are successful out in the big, bad world? It can be a little stressful thinking about what could go wrong but there are a few simple things to remember and easy steps to follow to give your veggies the best chance at living a long and “fruitful” life.

If you started vegetable plants indoors from seeds, here is advice on transplanting your seedlings safely and effectively.

1. Check your local planting calendar to insure proper timing to expected last frost. If planting in indoor planters, this won’t matter as much.
2. Prepare your plants for their new environment. Be sure the plants harden off; that is, gradually get used to unsheltered life outdoors. You can do this by leaving them outdoors for short periods in the week or two prior to transplant. 7 to 10 days before transplanting, set the seedlings outdoors in dappled shade that is protected from winds for a few hours each day, gradually increasing their exposure to full sun and windy conditions. If planting indoors, this won’t matter as much either.
3. Keep the soil moist at all times during the hardening-off period. Dry air and spring breezes can result in rapid transpiration. If moving outdoors, you should withhold fertilizer and water less often during their last week indoors (careful not to dry out the soil too much. Use the finger test.) . This will ready them for the shock of transplant. This is not necessary if moving to an indoor planter.
4. If possible, transplant on overcast days or in the early morning. Set transplants into loose, well-aerated soil that will capture and retain moisture, drain well, and allow easy penetration by seedling roots. Grab a handful of your garden soil. If you can form it into a ball, the soil is too wet for planting and the roots may rot. If the soil crumbles through your fingers, it’s ready for planting.
5. Soak the soil around new seedlings immediately after transplanting. This is where overwatering is not really possible. One piece of advice we’ve been given is to fill the hole with water and let it soak through, then water the transplant again once the new plant is in place.
6. Spread mulch to reduce soil-moisture loss. The amount of mulch may depend on your area, the season and the type of mulch. Here in the hot southwest we often use 3 to 4 inches of organic mulch like wood chips or compost to protect the soil. The mulch creates insulation which helps regulate temperature and moisture in the soil. It will also improve the quantity and quality of living matter in the sub-soil environment.
7. To ensure that phosphorus—which promotes strong root development—is available in the root zone of new transplants, mix two tablespoons of a 15-30-15 starter fertilizer into a gallon of water (one tablespoon for vining crops such as melons and cucumbers), and give each seedling a cup of the solution after transplanting. Bone meal and rock phosphate amendments will also improve phosphorus levels in your soil organically, but are slow working and should be worked into the soil a season or so in advance. Other great sources of Phosphorus are banana peels, crab shells, shrimp peelings, most grains and nuts.

Anything that raises soil temperature will help plants adjust to the shock of cold ground. Try raised planting beds and plastic mulch to boost soil temperature.