How to Start Your Indoor Garden

Save money and get a head start on your garden by starting plants and veggies from seed in your home. A garden expert shares her secrets for successful seedlings. 

It's still chilly outside, and some of us continue to face the threat of winter storms. But spring is almost here, and now is the perfect time to plant seeds and start growing your garden indoors. You'll get a jump on the outdoor season and be the first person in town with fresh veggies and blooming flowers when summer finally comes.

Choose Your Plants and Buy the Seeds

Home and garden centers sell plenty of seeds. But Melinda Myers, a Milwaukee–based gardener and author of more than 20 horticulture books, says you'll get a wider selection of plants with online or mail orders.

"Some lesser known or less popular plants, or newer varieties, aren't available yet in stores, so you have to start with seeds," she says. And with seeds, you can get what you want. So Myers encourages gardeners to take advantage of online or mail order by buying something unique, rather than buying easy-to-find radishes or roses that every home center carries.

Seeds are less expensive than plants, so you'll save money, but the package may contain more seeds than you need. In that case, Myers says, save some for next year. Or, plant them all and swap seedlings with friends when it's time to transplant them outdoors.

Make, Buy, or Reuse Containers

When you grow seeds indoors, any number of items can make good containers. Empty yogurt cups are the perfect size—about 2 inches square by 2 to 3 inches deep. Myers also likes to loosely wrap newspaper around a 2½-inch-thick dowel, press the lower ends of the paper together to create a bottom, then remove the rod and fill the newspaper cup with potting mix. This makes transplanting easy because the entire paper container is biodegradable, so it can be placed in the garden. "It's a way to recycle and reuse," she explains. Just be sure to use a container that lets excess water drain out. If roots sit in excess water, they rot. So cut holes in containers if they don't already have them.

Reusing containers that you bought flowers in last year also works great, but clean them first to kill any bacteria or disease that can harm seedlings. Mix one part bleach with nine parts water, and dip the container into the solution. Then dunk or rinse the container with water. "This disinfects for diseases, so you're starting with something clean," Myers says.

Myers also likes CowPots, which, as the name suggests, are containers made from composted cow manure. Like newspaper containers, they can go in the outdoor garden when it's time to transplant.

Dedicate an Indoor Garden Location

Pick a convenient spot in the house for the garden. When the seeds are first planted, heat is more important than light. Myers says you can start the seeds in a warm location that doesn't have to be lit. But once the seedlings break through the soil, they need light.

You can start seeds in a basement corner or even in front of a large window that lets in lots of sun for warmth. If the window is drafty, though, pick another spot—seeds and bulbs do best in warm soil. When the seedlings are visible, you can move them to a bright location under artificial lights. Or, better yet, a spot that receives sunlight as well as artificial light.

Prep the Soil and Plant the Seeds—When the Time is Right

Preparing the perfect soil is much easier for indoor gardens than their outdoor counterparts because you're dealing with a lot less space. Use a seed-starting or sterile potting mix right out of the bag.

Most seed packages tell you what time of the year to plant them based on your region or the average last spring frost. If you're not sure, ask a local gardener. It is possible to start too soon—if plants grow too large indoors, they get stressed when they're transplanted. But if you start too late, the seedlings don't mature enough indoors.

Likewise, once your plants are growing, don't transplant them outside too early. "We're all anxious to get started, but if you move outside too early and get a frost or the soil is too cold, all of that work you did is lost because the soil isn't warm enough," Myers says.

Water Wisely

The trickiest part of indoor gardening is giving the plants the right amount of water, without over-watering. "It's almost impossible to water correctly, so drainage holes in your containers are critical," Myers says, adding that she sometimes uses a mist bottle to water newly planted seeds. "You want enough water to moisten the soil without washing out the seed."

Check the soil moisture daily. "You want the soil about the consistency of a sponge that's been wrung out," she says. Sticking your finger into the soil is a quick way to tell if it's getting enough water. It should be moist all the way through so that roots will go downward. Covering the container with damp newspaper or plastic holds in warmth and moisture, but remove the cover once the plants break through the soil.

Light It Up

Even plants that receive natural sunlight benefit from cool and warm fluorescent lights. "You have the best results if you supplement your natural sunlight with light from a bulb," Myers says. "This gives you a full spectrum of light." She recommends full-spectrum CFLs and LEDs for more energy-efficient artificial lighting.

Place artificial lights 6 inches over the plants. "Either lower the containers as the plants grow, or raise the lights," Myers says. "That's why gardeners often have their lights on chains."

Hardcore gardeners place aluminum foil or whiteboard on the surfaces around containers to reflect light, Myers says. "This lets you maximize the light by reflecting it back toward the seedlings."