Starting tomato seeds
Starting your tomato plants inside from seed can give you a head start on the growing season and a limitless variety of tomatoes to choose from. Here's how to get started:
When to plant tomato seeds
In general, you should plant your tomato seeds six or seven weeks before the frost-free date in your area. Once you have more experience with tomatoes you can plant your seeds even earlier, especially if you plan to protect the plants with row covers or other methods to keep them warm once they are planted outside.
What kind of soil to use
Any commerically available seed starting mixture will work for starting tomatoes from seed. If you want to make your own you can use the following recipe:
- 4 parts peat or coir (Coir is a sustainable peat substitute made from coconut husks. Peat is mined from marshland, destroying natural habitats. When you have the option, use coir.)
- 2 parts perlite
- 2 parts vermiculite
Sowing your tomato seeds
Almost any kind of container will do as long as it has some drainage holes in the bottom. Fill the container with your soil mixture and pack it down well, leaving about half an inch between the top of the soil and the rim of the container. Then water the mixture ensuring that it is really saturated with moisture.
Scatter the tomato seeds evenly over the top of the soil surface allowing at least an inch between the seeds. Cover the seeds with a thin layer of potting soil.
Feeding
Seeds do not require any fertilizers until they produce their first set of “true leaves”. This will be the second set of leaves you will see. The first leaves that appear are called “seed leaves”. Start feeding your tomato seedlings after the first “true leaves” appear twice a week with a balanced, water-soluble fertilizer at half the strength indicated on the label.
Transplant the seedlings into separate containers
About three weeks after planting your seeds you can move each seedling into its own pot where the roots will have more room to grow over the next few weeks until it is planted out into the garden. Water them well before you start the process of moving them to individual pots. Use a bread knife, a nail file or a popsicle stick to gently lift each seedling free and replant in the new container at the same depth as it was before. Hold seedlings by their first leaves rather than the stems. At this tender stage, the stems can be easily bruised or broken. Press the soil snugly around the seedling to remove any air pockets and water well. Label each container with the name of the plant if you are growing different varieties.
At this stage the plants need lots of light, the more the better. Place them by a bright window or supplement the amount of light with artificial light. If you do not have special plant lights you can use a mix of incandescent lights and flourescent, or you can use flourescent lights alone. Making or buying a seed starting stand is a good idea so you can get the lights within a few inches of the tops of the plant. Give the seedlings up to 16 hours of light and 8 hours of darkness each day. Inexpensive timers can be found in most hardware stores that can be connected to your lights to automatically deliver the amount of light you want. If you are growing your seedlings beside a window without additional lights remember to keep rotating the plants in a quarter turn every day or they will keep growing toward the light and get lopsided.
Water the tomato plants only after the soil is very dry or if they start to wilt a little. If you can, water from the bottom by submerging each container in a larger container filled with water for a few minutes.
As the days get warmer and the first frost free day in your area approaches it will be time to get ready to move your new tomato plants into the garden.
Finally, after several weeks of caring for your seedlings, you should have healthy, stocky plants. Your tomato plants do need to be toughened up a bit to deal with the outside environment. About 2 weeks before it's time to plant in the garden, decrease the plants' water, stop fertilizing and, if possible, reduce the temperature. Then spend another week hardening the plants to the outside conditions. Start with a few hours exposure to shade each day, increasing to full sun over the course of a week.