How to Grow Vegetables Directly From Seeds in Your Garden
Growing garden edibles directly from seeds has many benefits. You're not limited to the varieties your local garden center carries — you can choose from hundreds of modern or heirloom types. Plus, you get to watch tiny sprouts of garden edibles appear as seeds begin to grow.
Depending on where you live, some seeds can't be sown outdoors and still produce a harvest before frost comes in fall. For example, northern U.S. summers are too short for tropical veggies, such as tomatoes and bell peppers, to grow from seed unless they're started indoors several weeks ahead of planting time. But many other seeds can be planted directly into spring gardens, no matter where you live. With the right tools, growing delicious vegetables from seeds doesn't get simpler.
Gardening & Healthy Living
Most vegetables do best in soil rich with organic matter. Adding materials such as compost or earthworm castings can help provide your garden with the organic materials it needs. Layer 3 to 4 inches of compost on top of your garden, and then incorporate it down into the soil several inches. Mix it in well, smooth it out, and you're set for simple seeds. You may want to also take soil samples and have your soil tested. You'll get a report that recommends more in-depth ways to improve your garden and its soil. Your local county extension agent can help with testing information and kits.
Spinach seeds germinate quickly, even in cool spring soil.
When possible, prepare your garden in fall, in case spring brings lots of rain and soggy soil. Working soil when it's wet actually changes its structure and makes it less hospitable to seeds and plants. By preparing your garden early, you're ready to plant as soon as soil dries out in spring. To know if it's dry enough, grab a handful of soil and squeeze it. If it crumbles away when you open your hand, start planting. If it forms a clump, it needs more time.
When you buy from an established seed company, the packaging includes all the information you need to start seeds right: how deep to plant, how to space your seeds and rows, how soon seeds will germinate (stop being dormant and start to grow), and how long you'll have to wait for harvest.
Seed packet information is important because every type of seed is different. For example, some seeds need light to germinate, so they're planted close to the surface. Others need darkness, so they're planted deeper. Seed packets will also include an expiration date. Seeds do expire, so don't expect old seeds to produce.
Seed packets contain lots of helpful information, in addition to seeds.
Seed packets also tell when to plant your seeds outdoors. This may be the most important piece of information of all. Different seeds germinate at different soil temperatures, which differ from air temperatures. If the soil is too cold — or too hot — germination won't occur.
Some packets list minimum soil temperatures or the optimal temperature range for planting. Others indicate when to plant in terms of how many weeks before or after your area's typical last spring frost date. You can buy an inexpensive soil thermometer at most garden or hardware stores. Basic models look like a meat thermometer for your oven, but with a different temperature scale. If you're unsure about typical frost dates in your area, your extension agent can help with that, too.
The following garden vegetables, listed from earliest planting dates to latest, all do best when seeded directly into your spring garden.1,2 Many of these seeds also yield second crops when planted in late summer, once soil temperatures cool down.
- Lettuce. Their leaves are tender, but lettuces are tough. Sow seeds as soon as soil thaws and is dry enough to work, usually once soil temperatures hit 35 degrees Fahrenheit (F). Harvest baby leaf lettuce at any size.
- Spinach. Like lettuce, spinach prefers cool weather. Plant seeds as soon as soil can be worked. Harvest baby spinach any time you choose.
- Peas. Plant peas once soil warms above 40 F. This is usually about five weeks before your area's last expected frost. Eat snow peas as soon as peas start to form in pods. Let snap peas grow to full size.
- Carrots. Plant carrot seeds when soil warms to 40 F or higher. When you see their shoulders, it's harvest time. Carrot roots don't like to be disturbed, so be extra careful when you weed.
- Radishes. Radishes grow fast and taste best when young and tender. Plant seeds once soil reaches 40 F, and get ready for lots of radishes. Like carrots, these root crops don't like to be disturbed.
- Beets. Seed beets once soil warms to 40 to 50 F, about four weeks before your last frost. Beet leaves are flavorful and add reddish color to salads. You can harvest up to one-third of the greens without hurting your crop.2
- Sweet corn. Sweet corn germinates in soil at 50 F, but it does much better if soil warms a bit more. As a guide, watch for blooming forsythia shrubs or germinating crabgrass in your lawn. Both happen when soil reaches 55 F.
- Beans. Plant beans around your last expected frost date, when soil temperatures warm to 60 F or more. Harvest green beans with the pods still thin and tender. Let dried bean types grow until mature.
- Cucumbers. Sow cucumber seeds after your last frost date, with soil at 60 F or warmer. Harvest baby cukes for bite-size snacks or pickles. Let others grow larger, but enjoy them while they're still young and tender.
- Squash. Summer and winter squash, including zucchini, won't stand any cold. Plant only when soil and air both warm up, at least two weeks after your last frost date. Soil temperatures must be at least 60 F, but 70 to 95 F is even better.
Before planting your seeds, mix Pennington UltraGreen All Purpose Plant Food 10-10-10 into the prepared soil. Specially formulated with the right balance of essential nutrients, this plant food provides a healthy, strong foundation - leaving you with tasty vegetables.
As soon as your seeds are in the ground, mark your rows to help you remember what seeds are planted where. Water seeds gently; you don't want to wash them away before they take root. Keep your seed packets tucked nearby in a garden shed drawer or a garden journal. You'll want to refer to them for reminders and growing tips as seeds sprout and grow.
By growing garden vegetables directly from seed, you and your family can enjoy all the benefits of homegrown edibles plus the added fun and ease of starting seeds from scratch outdoors. The GardenTech® family of brands wants you to discover all the joys and rewards of gardening, and the GardenTech blog is here to help.
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1. Harrington, J.F., “Soil Temperature Conditions for Vegetable Seed Germination," University of California-Davis.
2. Steil, Aaron, “Vegetable Harvest Guide," Iowa State University Extension and Outreach, July 2004.