Let’s talk about starting seeds.
Part 1 of 4
The greenhouse where all the seeding takes place has been warmed up and we are seeding peppers and tomatoes. These first few tomatoes will be the ones blossoming and have fruit set on the vines by mid to late May. In the seeding house we have a piece of equipment that I call a humidor. I’m not sure if that is the correct term, but essentially it is a thermostatically controlled heated closet with clear plastic sides, a lot of wire rack shelves and a water pan at the bottom. I will explain our process and then offer some ideas to adapt it for home use. Sow good seed! Remember seeds are living things! Buy from a reputable company. There are low priced seeds on the market, but the problems that can result more than wipe out the savings.
Use a soil designed for starting seeds. Potting soil can be used if it is NOT enhanced with fertilizer. A fine textured soil is best, so if you are using regular potting soil, you may want to sift out some of the larger particles. Fertilizer in the soil can cause salts to form that can burn tender roots. Keep the soil warm. This is the number 1 stumbling block. Most flower seeds need an actual soil temperature of 75*F to achieve proper germination. That means day and night. I have a humidor, but an electric warming pad can help the home gardener maintain temperature. These are available at most large garden centers. There are some annuals that require a lower temperature of 65*F and they are pansies, phlox, and snapdragons. Some require a higher temperature of 80, 85 or even 90*F. Peppers and tomatoes need a temperature of 80-85*F.
Moisten (not dripping wet!) the soil and plant the seeds. Leave very fine seed like petunias and alyssum uncovered. They will nestle into the soil. Some seeds need a period of darkness (usually 3 days) to germinate. These include verbena, dusty miller, pansy, phlox, and portulaca (moss rose). Sowing depth for most seeds in about ¼ -3/8 inch. Remember to label your seed plantings. Tips for labeling. Use plastic picnic knives and label with a marker, or use popsicle sticks with waxy pencil. These can be transferred to the garden when transplanting.
Keep the soil moist until sprouting occurs. Again, I have a humidor that maintains a high level of humidity so the soil does not dry out. For the home gardener, cover the soil with plastic wrap or purchase trays with plastic domed covers. My mother always used plastic wrap with toothpicks to keep the wrap elevated just off the soil surface. Remove the plastic covers when seedlings emerge. Sunlight coming through the plastic can burn the young foliage. Part 2 tomorrow.