How to Reverse Leaf Curl in Seedlings

Harden off seedlings that were purchased from a greenhouse or started indoors. Transplant shock can cause leaf roll. Set the seedlings outdoors in a partially shaded area for about two hours to start out. Increase the time and sun exposure gradually. After about a week, they will be hardened off and you can plant them outdoors.

Do a soil test before adding any fertilizers to the planting area. Overfertilization can cause leaf curl. If you have added too much fertilizer, you can water deeply for a week to try to flush the fertilizer from the top layer of soil, or you can dig up the seedling and plant it in a fertilizer-free location.

Plant away from lawns and do not use mulch from cut grass that may contain herbicide residue. Plants such as tomatoes are sensitive to herbicides including 2,4-D, and a small amount of exposure to drifting herbicide can cause leaf curl. Remove any contaminated mulches. Transplant the seedlings in a new location if the soil in the current location contains herbicides.

Shade new seedlings to keep the temperature of the plants below 95 degrees Fahrenheit. Too much sun or heat can cause leaves to curl to help the plant reduce water loss.

Maintain adequate moisture levels. Most seedlings need at least 1 inch of water per week. If they are planted in moist soil and go through a dry period, the leaves will curl to retain moisture. Keep the moisture level constant by watering during dry weather.

Protect seedlings from the wind. Wind can reduce moisture levels around the plants. When the wind stops and the moisture level is restored, the leaves will uncurl.