The planting dates for most garden vegetables are at least six weeks away, but gardeners who want to grow their own plants need to be starting them indoors now.
The summer garden generally consists of vegetables that can be direct seeded when the soil temperature reaches an appropriate level, such as carrots, beets, radishes, greens, beans, corn and okra, and those that must be grown from started plants, such as the cole crops, tomatoes, peppers and eggplant.
As soon as the ground dries out enough to be worked, lettuce, spinach, radishes and carrots can be seeded directly in the soil. Planted this early, the seed should be sowed in a sunny part of the garden.
Broccoli, cabbage and kohlrabi plants can be set out in the garden in early April, or even late March if your garden is sheltered from the wind. I've lost plenty of plants in March, however, with wind and late freezes being the primary culprits.
Start the plants now in a greenhouse or under lights indoors and you can put them in the ground around April 1.
In this climate, the average date of the last killing frost falls around April 20. As soon as the danger of frost has passed, we can begin to set out the warm-weather, frost-intolerant plants, such as tomatoes, peppers, eggplant and most herbs.
Start your seeds in moist soil that is intended for starting seeds. Regular potting soil may retard germination and early growth, and it's more susceptible to mold and fungus. Starting soil has been sterilized and will drain well while remaining moist. While starting soil is usually more expensive, your plants will be healthier.
However, the primary requirement for plants started indoors is adequate light. If you have a greenhouse, or a greenhouse window with southern exposure, this won't be an issue. But if you're going to use lights, you'll need to position a fluorescent fixture a couple of inches above the soil in which your seeds will germinate. You then must raise the lights as your plants grow.
Shop lights are perfect for this purpose. Outfit them with one hot and one cold (red and blue) tube for the full range of light, and use the chains on the light fixture to adjust the height of the lights. The lights can be suspended from hooks placed in the underside of a shelf, for example.
For most vegetables, started plants will thrive in the garden four to six weeks after germination, particularly if they have been transplanted a couple of times into progressively larger containers, and then hardened off.
The plants should be moved outdoors about three weeks after germination, when they have developed multiple sets of leaves, to allow them to acclimate to outdoor conditions. Until the plants are hardy enough to withstand shifts in temperature, they should be brought indoors at night and protected from chills until it's time for them to go into the ground.
For gardeners who start large numbers of plants, the hardening-off process can be an enormous undertaking. You have to move the plants twice a day and double up on the watering because plants dry out more quickly outdoors. It's a headache, but hardening off your plants can determine whether they do well in the garden.
In fact, when you buy plants in a greenhouse, be prepared to harden them off if they haven't been spending the night outdoors. When plants fail to thrive after they leave the greenhouse, this is often the reason. Not only do they endure the shock of being transplanted into the ground, but they also may be experiencing nighttime temperatures for the first time.