Planting from seeds gives your junior gardeners a glimpse at the life cycle of a plant -- science in action. Understanding the differences between planting directly outdoors and starting seeds inside helps you decide which option is the best for your garden. With the different processes in mind, you can plan your veggies and get your seedlings growing.
Starting seeds indoors allows you to get a jump start on the normal growing season. When the weather warms up enough to plant outdoors, you already have a sturdy seedling. Some plants, such as tomatoes (Solanum lycopersicum), need that extra growing time before outdoor conditions are ideal. Without the early start, the plants won't mature before the weather cools off again in the fall. If you plant seeds directly outdoors, you have to wait until the soil warms enough for the seeds to germinate. The recommended outdoor planting time varies by plant, but the seeds that are directly sown outdoors mature later in the season due to the late start time.
Indoor sowing requires a few more supplies than you'd need if you planted the seeds directly in the garden. Small containers or a large, divided tray is often used to start seeds indoors. You have the choice between reusable plastic trays and pots made from organic materials that you plant with the seedling when you transfer it to the garden. You need the soil-less mix designed for starting seeds. All those trays and pots need a place to stay until they are ready for outdoor planting. Fluorescent lighting is another extra item that is beneficial to provide a more reliable source of light than natural light sources. When you direct-sow outdoors, you won't need extra materials beyond your basic gardening tools.
The process for planting seeds is similar, except you start the plants in pots or planting trays indoors. Starting indoors does add the extra step of transplanting the seedlings outdoors, and the plants need to be hardened off before you actually plant them in the garden. The hardening off process involves setting the plants outdoors for gradually longer times so they get used to the outdoor conditions. The seedlings then get planted into the garden. Some plants, such as carrots (Daucus carota), aren't suited to transplanting and should be directly planted outdoors.
The indoor growing environment is easier to control than outdoors since you eliminate weather variations. With a grow light, you control the amount of light the germinating seeds get. A sudden decrease in temperature or a late frost outdoors can damage seedlings that are just emerging. Indoor planting also gives you better control over watering. Once the seedlings become established, they can better withstand the fluctuating conditions outdoors.