Starting seeds indoors is a wonderful way to get a head start on your garden each year. It’s also a great way to save money. You probably know that starting your own plants from seeds will reduce how much money you spend in the garden each year. For example, consider a pack of lettuce seeds. One pack of lettuce seeds will contain anywhere from 25-50 seeds. You can usually buy a pack of lettuce seeds for around half the price of a six-pack of started lettuce plants. You’ll get more bang for your buck with seeds.
There are two basic options for growing from seed: starting indoors and direct sowing. What is the difference?
Starting seeds indoors is as simple as it sounds. You’ll create an indoor growing space where you provide soil, lighting, water, fertilizer, and warmth that your seeds need to germinate, complete kits for indoor growing here. Many garden seeds need warm temperatures to germinate and begin growing. Once the weather warms, you will transplant the started plants into the garden bed where they will mature and start to produce or flower.
Direct sowing involves planting seeds directly into the garden soil where they will germinate and continue to grow. Plants that are direct-sown will not be transplanted later. They spend their entire lives in the same place.
Now that you’ve decided you want to start your own seeds, how do you know which ones should be started indoors and which ones should be planted outdoors (direct sown)? There are a couple of critical considerations to guide your decision: the type of plant and your climate.
While starting plants indoors can seem intimidating if you haven’t done it before, you will find that it isn’t complicated. When you provide the right amount of water, fertilizer, and light, it’s easy to grow healthy, vigorous seedlings indoors.
Which plants should be started inside? This depends on where you live. Some climates have a long enough warm season that they can direct sow more plants outdoors. If you live in a colder climate (often considered to be USDA Hardiness Zones 6 and lower), you might find that you start most of your plants indoors so that they have enough germination and growing time to produce during your shorter growing season. Refer to Park Seeds’ “days to maturity” (included in product descriptions online and on your seed packets) and count back from your area’s expected last frost.
Generally, summer crops with smaller seeds can be started indoors. Although any seed can be started inside, you’ll want to direct sow the ones that can be sown outdoors to reserve space for the ones that need a little extra time.
Plants like herbs, flowers, tomatoes, peppers, eggplants, cucumbers, melons, Brussels sprouts, and cruciferous vegetables can be started indoors. These plants either have a longer growing cycle or have slower growing root systems. Starting them indoors will give them an advantage when the weather warms up enough to plant outdoors.
INDOOR LETTUCE AND HERB GARDEN
Lettuce and leafy greens can be grown entirely indoors. These plants don’t take up much space and can be grown quickly and easily inside. Some types of lettuce can be harvested in as little as 4-6 weeks, making it simple to grow a continuous supply of lettuce inside. Leafy herbs like parsley, cilantro, oregano, and thyme don’t take up much space either. These herbs are perfect for growing indoors in small spaces, even your kitchen counter. Herbs and lettuce seeds can be directly sown into small pots or growing systems and grown indoors indefinitely.
As another general rule, seeds that are longer than they are wide can be sown outdoors. Squash, melons, beans, peas, and okra can be sown outdoors once the threat of frost has passed. Simply sow them into the soil at a depth that is twice as deep as the seed is wide.
Many flowers can be directly sown into the ground also. Flowers with large seeds like marigolds and nasturtiums take off wonderfully when planted directly into the soil.
Although you can technically direct sow any seed, not all of them are well-suited for direct sowing. Some plants take longer to get started and to start producing. These seeds should be started indoors to lengthen the growing period and harvest for those plants. The best plants for sowing outdoors are ones that develop roots quickly, become established, and grow rapidly.
Most root crops should also be direct sown outdoors. Root crops develop strong root systems so quickly that you may not be able to well under the soil line to transplant them successfully. To avoid shocking root crops, direct sow them outdoors once the weather is warm enough. Potatoes, sweet potatoes, onions, garlic, beets, radishes, carrots, and other root vegetables should be planted outdoors. Start these plants from seeds or sets to get the best results.
WHAT IF MY GROWING SEASON IS SHORT?
This is a question that comes up frequently in colder climates. You can start any vegetable, flower, or herb indoors with the proper care. Plants that have a long growing period can be started and nurtured indoors. Once the weather warms up, you can transplant them outdoors.
Keep in mind that if you start seeds indoors and you plan on caring for them indoors for more than 6 weeks, you’ll want to be prepared to transplant them into larger containers. This will help you avoid root-bound plants that become injured when you transplant them.
Larger containers will extend the amount of time that you can grow these plants indoors, too, since you’ll give their roots more room to expand. The bonus is that you’ll have more mature plants when it’s time to transplant outdoors. This extended time frame should allow you to harvest and enjoy these plants earlier and before the next season of cold weather sets in.
Making use of cold frames, row covers, and greenhouses can further extend a short growing season, but they aren’t a necessity to be able to grow. Keeping cold weather protection on hand will give you the confidence to plant outdoors. If there’s a threat of a cold snap, use them to protect your plants. In a pinch, an old bedsheet can save plants from a hard frost.
Post by Shelby DeVore, founder of Farminence and host of the Backyard Vegetable Gardener’s Summit. Shelby is a passionate gardener with over 20 years of experience gardening and growing food at home. Shelby recently relocated to north Texas with her husband and three children where she’s excited to explore a new gardening zone and build a new farm.