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By Dr. Ping Yu, Robert Westerfield, Gabrielle LaTora, Whitney Ottinger,
Dr. Bethany Harris, and Rich Braman
The seed catalogs are showing up in your mailbox this time of year, and it’s easy to get excited as you think about your spring and summer garden. There’s something deeply satisfying about growing your own plants from seed. Those packets hold big potential – a single one can produce dozens of plants for far less than buying transplants at a nursery. Starting seeds indoors also gives you a jump on the growing season, getting plants established before Georgia’s summer heat and insect pressure set in. A little preparation goes a long way, and the process is simpler than you might think.
Start with a Plan
Successful seed starting begins well before planting day. First, decide what you want to grow and how you’ll grow it. Some vegetables – like tomatoes, peppers, broccoli, and lettuce – benefit from being started indoors and transplanted later. Others, including beans, corn, carrots, and squash, grow best when seeds are sown directly into garden soil (Dorn & Pennisi, UGA Extension Bulletin 1432).
Check your seed packets for planting guidance. Seed packets are one of your best resources. They contain recommended planting dates, germination rates, days to maturity, and whether a crop is best direct-seeded or transplanted. Understanding days to maturity is especially important – if you start seeds too early, seedlings may outgrow their containers before outdoor conditions are right for planting.
Time it right. Most indoor seeds are started 6–8 weeks before your area’s last expected frost date (Dorn & Pennisi). In much of Georgia, that means sowing tomato seeds indoors in late February or early March for an April transplant. UGA Extension’s Vegetable Planting Chart can help you dial in your timing based on where you live.
Choose high-quality seeds from reputable sources. As you flip through seed catalogs, select varieties well suited to your climate and, when possible, resistant to common diseases. You’ll notice some seeds labeled “open-pollinated” or “heirloom” and others marked “F1 hybrid.” Both grow well in the garden, but open-pollinated and heirloom varieties produce seeds you can save and replant – a rewarding practice once you’re comfortable starting from seed (Griffin et al., UGA Extension Circular 1242). UGA Extension’s publication Best Garden Vegetable Varieties for Georgia offers a list of varieties that have been trialed and proven to grow well in the state – a great starting point, especially for newer gardeners. Planning early also helps you order seeds before popular varieties sell out.
Know What to Start Indoors vs. Direct Sow
Not all plants respond well to transplanting. Knowing which method works best for each crop saves time and improves results.
Start indoors and transplant: Tomatoes, peppers, broccoli, cabbage, lettuce, kale, collards, and chard all develop stronger root systems when started in a controlled environment before moving to the garden (Dorn & Pennisi).
Direct sow into the garden: Large-seeded crops and root vegetables that don’t transplant well should go straight into prepared soil. This includes beans, corn, carrots, beets, squash, cucumbers, melons, okra, and radishes (Dorn & Pennisi).
Gather Your Supplies
You don’t need fancy equipment to get started, but a few key materials make a real difference.
Use a sterile, soilless seed-starting mix. Avoid garden soil – it’s too heavy, holds too much water, and often contains weed seeds or disease organisms that can kill young seedlings. A good seed-starting mix is lightweight, fine-textured, and drains well. Most commercial mixes contain peat moss, perlite, and vermiculite, which balance moisture retention and drainage (Dorn & Pennisi).
Choose clean, well-draining containers. Seed trays, cell packs, small pots, and even clean recycled containers all work as long as they have adequate drainage holes. Clear plastic containers with lids can double as miniature greenhouses during germination. If you’re reusing containers, sanitize them first with a solution of one part chlorine bleach to nine parts water, then rinse thoroughly (Dorn & Pennisi).
Have supplemental lighting ready. A sunny windowsill may help, but grow lights positioned 2–3 inches above seedlings will produce much stronger, sturdier plants. Plan for 14–16 hours of light per day. Without enough light, seedlings become tall, thin, and weak – stretching toward the nearest window instead of growing stocky and strong (Dorn & Pennisi).
Label everything. This is easy to skip but hard to recover from. Many seedlings look nearly identical during early growth stages. Proper labeling ensures each plant gets the right care and goes into the garden at the right time.
Plant Your Seeds
Fill your containers with moist seed-starting mix and plant seeds at the depth listed on the packet. Bob Westerfield, UGA Extension consumer horticulturist, recommends a good rule of thumb: plant seeds twice as deep as their size. Very small seeds – like lettuce – should be gently pressed onto the soil surface and barely covered, since they need light to germinate (Westerfield; Dorn & Pennisi).
Water gently. Use a spray bottle or small watering can to keep the growing media consistently moist without washing seeds away or compacting the soil. Overwatering causes seeds to rot; underwatering causes embryos to dry out before they can sprout. Steady, even moisture is the goal (Dorn & Pennisi).
Boost humidity during germination. Covering trays loosely with plastic wrap or a clear dome helps retain moisture around germinating seeds. Remove covers as soon as seedlings emerge to allow air circulation and prevent disease (Dorn & Pennisi).
Provide warmth. Most common vegetable and flower seeds germinate best in soil temperatures between 65–75°F. A seedling heat mat placed under your trays can maintain steady temperatures, especially in a drafty house. Once seeds sprout, gradually lower the temperature to around 65°F and move seedlings under bright light (Dorn & Pennisi).
Care for Your Seedlings
Once your seeds are up, the next few weeks are critical. Seedlings have small, developing root systems and can dry out quickly – check them daily, especially if they’re on a heat mat or under lights.
Thin early. Gardeners tend to plant more seeds than needed as insurance, which means crowding is almost inevitable. Once seedlings are up, thin them to the spacing recommended on the seed packet. Snip extra seedlings at the soil line with scissors rather than pulling them – tugging disturbs the roots of the plants you’re keeping (Dorn & Pennisi).
Fertilize lightly. After the first set of true leaves appears – these are the second set of leaves you’ll see, since the first pair are seed leaves (cotyledons) – begin feeding with a liquid fertilizer at half the recommended label strength. Repeat every two weeks. Avoid fertilizing plants that look wilted or moisture-stressed, as the fertilizer can cause further damage (Dorn & Pennisi).
Keep lights close. As seedlings grow, raise your grow lights to maintain that 2–3 inch gap above the foliage. Consistent, close light is what keeps seedlings compact and sturdy rather than leggy and fragile (Dorn & Pennisi).
Prepare for the Big Move
Before seedlings go outdoors permanently, they need time to toughen up through a process called hardening off.
Harden off gradually over 7–14 days. Start by placing seedlings in a shady, sheltered outdoor spot for just a few hours, gradually increasing their exposure to direct sunlight, wind, and temperature swings. Bring them back inside each evening at first. This slow transition prevents transplant shock and sunburn (Dorn & Pennisi).
Transplant on a mild day. Once the danger of frost has passed and your plants are hardened off, choose a cloudy day or plant in the early morning or late evening to reduce stress. Water well immediately after transplanting and continue watering consistently for the first several weeks as roots get established.
Prepare your planting site. Most vegetables need at least 6–8 hours of full sun and well-draining soil. A soil test through your local UGA Extension office can identify any amendments needed to improve plant health before your seedlings go in the ground.
A tip for tomatoes and peppers: These crops benefit from deeper planting. Bury tomato stems up to the first set of leaves – or even lay them sideways with the top leaves above soil level – to encourage strong root development along the buried stem (Cabrera, UGA Extension).
Ready, Set, Grow
With a plan, a few basic supplies, and some patience, starting seeds is one of the most rewarding things you can do in the garden. It’s a cost-effective approach that gives you access to a wider range of varieties – including heirlooms and unique cultivars you won’t find at the local garden center. It also lets you extend your growing season by getting plants going indoors well before outdoor conditions are ideal. And once you’ve grown a crop you love – especially an open-pollinated or heirloom variety – you can save seeds from your best plants to grow again next year. We’ll have more on seed saving later this season.
Beyond the practical advantages, there’s real satisfaction in watching a tiny seed become a plant that feeds your family.
If you’re new to seed starting, pick two or three vegetables you enjoy eating and give it a try this season. If you have questions or need guidance, reach out to your local UGA Extension office.
Resources
UGA Extension Bulletin 1432, Starting Plants from Seed for the Home Gardener by Sheri Dorn and Bodie Pennisi:
https://extension.uga.edu/publications/detail.html?number=B1432
Starting Your Spring Vegetable Garden from Seed by Emily Cabrera, UGA Cooperative Extension:
https://fieldreport.caes.uga.edu/features/vegetable-garden-seed-starting
Best Garden Vegetable Varieties for Georgia, UGA Extension:
https://extension.uga.edu/publications/detail.html?number=C1326
Vegetable Planting Chart, from Vegetable Gardening in Georgia (UGA Extension Circular 963):
https://secure.caes.uga.edu/extension/publications/files/html/C963/C963VegeChart.pdf
UGA Extension Circular 1242, Seed Saving in Georgia Gardens by Becky Griffin, Ashley Hoppers, Rosann Kent, Clark MacAllister, and Jacob Williams:
https://extension.uga.edu/publications/detail.html?number=C1242
Dr. Ping Yu, Assistant Professor & Ornamental Extension Specialist, Department of Horticulture
Robert Westerfield, Consumer Horticulturist, UGA Extension, Department of Horticulture
Gabrielle LaTora, Agriculture & Natural Resources Agent, UGA Extension Fulton County
Whitney Ottinger, SARE Sustainable Agriculture Educator, Center for Urban Agriculture
Dr. Bethany Harris, Director, Center for Urban Agriculture
Rich Braman, Systems Administrator & Developer, Center for Urban Agriculture
Department of Horticulture / UGA Cooperative Extension / Center for Urban Agriculture / Southern SARE
