Recently in the Skillin's Garden Log we have discussed the ABC’s of Seed Starting. We reviewed how to start seeds indoors and when to start seeds indoors. (If you need a copy of that article, just let me know!). It may be time to transplant your seedlings when they show their first true leaves! This brings us to sections E, F, and G of the ABC’s of Seed Starting.
Equal parts of peat moss and vermiculite makes a good growing medium for your seedlings to be transplanted into now that they have their first true leaves. Unless you sowed your seeds directly into an individual peat pot (which I actually recommend in many cases), you will want to transplant your seedlings from their starting trays to give them more room and a better chance to grow. For containers, consider using plastic 6-packs, 3” or 4” peat pots, or peat flats, spacing seedlings one to two inches apart. You may also wish to add equal parts soil and sand to your mix as this makes the transition to the soil outdoors that much easier. Moisten your mix with warm water to make handling manageable. Fill each container within a quarter inch of the top and tamp down. Gently tap the seedlings as a group out of the container they were started in. Carefully separate the seedling, attempting to keep as much of the original medium around the roots as possible. Using a label or a pencil, make a hole for each seedling in your mix. Generally you will want to place the seedling at the same soil level it was previously. (Bushy type plants like lettuce or petunias need to be planted at the same soil line so their growing point is not buried, where upright plants such as tomatoes can be planted to the base of the first leaves and roots will develop along the stem that is buried.) Pinch the soil in around the base of the transplanted seedling. Set in a pan of warm water for bottom watering, as this will be the least likely way to disturb the new transplants.
Fungus disease known as damping-off can be the worst enemy of new seedlings. A seedling will appear perfectly healthy then you discover it has toppled over- a black line of rot cutting through its stem. Over crowding, being too warm and damp, and still air can all lead to this infectious loss. Prevention is the best weapon against damping-off. If you do use a mix with soil or sand, be sure to pasteurize it first. Make sure your seedlings get enough air circulation. Don’t keep them covered with plastic and don’t over water.
Growing your seedlings on, place them in a very sunny window using a sheer curtain in between to prevent scorching, or place under artificial light, adjusting the height as they grow. Fertilize once a week with a quarter strength solution of a liquid organic fertilizer. Continue to water and grow on until ready to set out.