Once your seedlings have emerged from the soil you must remove the plastic covering and gradually move them into direct light over a period of days. The seedlings will need to be watered more often now that they are out of their “greenhouse” so check your containers daily. Remember to water your plants by putting them in a basin of warm water so that the water enters the soil from the bottom and the top is not drenched. Once the 2nd set of leaves, the “true leaves”, emerge you should fertilize you plants by adding ¼ the recommended dose (read the plant food directions) all-purpose soluble plant food to the water once a week. When the seedlings are 3” tall you can water and feed them from above. If you notice that the seedlings fall over and have a brown nick at the soil line but the leaves are still OK, you probably have damping off, a fungus disease that can appear when the top of the soil is too wet. Remove the diseased seedlings and let the top of the soil dry out. Sand put on the surface of the soil dries out quickly and helps to prevent damping off. A small fan to increase ventilation will also help. A fungicide spray will probably solve the problem. Rotate the containers a quarter turn every 4 days so that the seedlings get light from all sides.
When 4 true leaves have formed you are ready to thin and transplant the seedlings. By this time they are probably spindly and crowding each other. Your goal is to have all your seedlings about 1” apart so fill enough new containers with good garden soil or potting mix to accomplish this.
Equipment (see Ten Steps for Starting Seeds, Karensgardentips.com for a more detailed description and explanation)
1. Containers as for germinating seeds.
2. Potting soil
3. Dibbler or pencil
4. Tongue depressor or spoon
5. Labels and permanent marker
6. Plant food (like Miracle Grow, 10:10:10)
Ten Steps for Successful Seedlings: thinning and transplanting
1. Water the containers with seedlings thoroughly from the bottom with warm water.
2. Moisten the soil in the new containers.
3. Use a dibbler or pencil to make 1” deep holes 1” apart in the soil of the new containers.
4. Using a tongue depressor or handle of a spoon, carefully remove a seedling from its original container and place it in the prepared hole, slightly deeper than it was before. Fill in the soil around it gently. Handle the seedlings by the leaves or roots NEVER by the stems.
5. Label the seedlings.
6. Water the seedlings thoroughly using ½ the recommended dose (read the plant food directions) all-purpose soluble plant food from the bottom.
7. Over a period of a few days gradually move the containers to bright light.
8. Watch the soil moisture daily and do not let the soil dry out.
9. Fertilize weekly with ½ the recommended dose of all purpose soluble plant food.
10. Rotate the containers a quarter turn ever 4 days so the plants will get light evenly on all sides.
Once the weather gets warm you will want to move the plants into the garden but first you must harden them off. They have been growing in a comfortable environment where they do not experience wind, rain, full sun, or greatly fluctuating temperatures and they are not fully equipped to tolerate these conditions yet. By slowly introducing them to the outdoor environment they will develop the necessary tissue to survive and do well. On the first day put the containers of plants in a shaded and protected area but bring them in at night. Three to four days later put the container of plants in an area where they will receive about a half day of sun (3-4 hours), bringing them in night. . Three or four days later put them in their permanent place. Check the soil moisture every day and water the plants before the soil dries out.