Don't let damp, chilly spring weather stymie your urge to grow. Set up your own seedling nursery indoors. It's fun, fulfilling, and saves you money. Here's how to get started.
Choose a potting mix specifically formulated for seed growth, such as Miracle-Gro® Seed Starting Potting Mix. A good seed starting mix will hold moisture, drain well, and have a fine texture that allows young leaves to emerge easily.
Look for small trays or shallow containers 2-3 inches deep. You will also need plastic wrap, plastic dome lids, or a glass covering to help retain humidity and warmth. The clam-shell containers that grocery stores use for berries and cherry tomatoes work fine. Your seedlings won't be in these containers long so they don't need to hold much soil mix.
Lettuce, beet, and spinach seeds germinate easily at room temperature. Warm-season plants, such as tomatoes and peppers, require a boost of heat to encourage sprouting. A sunny windowsill or the top of the refrigerator are good places to start seeds. Small propagation mats that keep soil in the 68-70 degree range are available at most major garden centers.
Fresh seeds are vital for good germination. Look for the "packed for" date on the seed pack. You'll also see the seeds' germination requirements - soil temperature, whether the seeds need dark or light to germinate, and how many weeks before the last frost to plant indoors.
Don't get too far ahead of Mother Nature. It's always better to set out stocky, healthy seedlings in the garden rather than plants weakened from growing indoors too long. Start seeds of cool-season plants like lettuce, beets, kale, and spinach indoors 3-4 weeks before planting outside. Grow heat-loving plants like peppers and tomatoes indoors 4-6 weeks before the last frost date in your area.
Moisten your potting mix to the consistency of a wrung-out sponge. Fill the container with mix and tamp it down lightly, but don't compact. Sow seeds on the soil's surface, taking care to space them from 1/8 to 1/4 inch apart - more space for larger seeds. Cover the seeds with a thin layer of potting mix and press lightly. Seeds must be in contact with the soil to germinate, but, again, don't compact. Next, soak the seed tray in a shallow container of warm water until the soil mix is thoroughly moistened but not saturated. Then remove it from the water and allow it to drain thoroughly. Cover the seed tray and place it in a warm area to germinate.
Check your seed container daily for signs of germination. As soon as the first seedlings break through the soil, move the plants to a place with at least 6 hours of bright light and good ventilation, and remove the tray covers.
Too much water encourages fungal growth, yet too little water dries out delicate roots, making your seedlings wither. Test to see if your container is ready for water by lifting it. If it feels light, it's time to water. If it's still heavy, wait another day or two. Generally, you want your soil to be moist, but not saturated. Use a spray bottle to water or set the container in a shallow tray of water to soak for a few minutes.
The first 2 leaves that emerge from the seed are called seed leaves, or cotyledons. The third leaf to emerge is the plant's first true leaf. When your plants have 2-4 of these true leaves, it's time to transplant them from the seed tray into small pots of their own, or, depending on timing, into the garden. Read our articles on container gardening and how to start a garden to take it from there.