How to Grow the Best Vegetables From Seed

There’s nothing more satisfying than nurturing a crop right from its beginnings as a humble seed. Contained in those little miracles is everything a plant needs to get started. But what happens after it has sprouted? That’s where you come in.

Planting and tending your seeds is an easy activity involving several steps. From feeding and watering to fending off pests and diseases, we can help you nurture your plants until they reach just the right size for transplanting.

Why grow vegetable plants from seed?

Growing plants from seed is something anyone can do with the right care and attention. But why do it in the first place? Isn’t buying starter plants easier?

In some ways, yes. But there are many good reasons why you might consider starting your own vegetables from seed this year.

• Growing from seed saves money. With the cost of starter plants rising, seeds cost pennies a plant when all is said and done.
• More plant varieties are available from seed. Want to grow something other than Early Girl tomatoes and standard issue lettuce? Nurseries don’t have the shelf space to stock more than a few varieties of each plant during garden season, but seed companies do! They have dozens of varieties just waiting to be samples. Plus, you can find seeds just right for your area.
• You’ll produce less waste. It’s a hard-to-admit truth that buying seedlings and plants generates a lot of plastic. It’s still preferable to buying crops from far away but starting your own plants from seed can help cut down on some of this waste.

No matter what your reasons, growing your garden from seed brings satisfaction and knowledge. So let’s get started.

Related: Where to Buy Organic Seeds
 

How do you grow from seed?

There are two main ways to grow vegetables from seed: 1) starting your seeds indoors in trays or 2) sowing them directly outside into the ground.

Seed trays

Growing in seed trays lets you get a jump on the season, since you can plant many weeks earlier in the warmth of indoors. Later, you can transfer your healthy plants outside when the temperature rises.

Indoor seeding is perfect for plants that require a slightly longer growing time than your local climate provides. It’s also good if little seedlings need protection from pests that might not bother a bigger, stronger plant.

Once planted in trays, your seeds will sprout and grow quickly. Be sure not to leave them indoors too long, or they may outgrow their pots and weaken. To remedy this, check the planting dates on your seed packages. Hardening off your seedlings involves moving them outdoors for a short time each day until they’re accustomed to the cooler temperatures. The easiest way to help seedlings adapt before planting outdoors is to place them in a cold frame or a sunny spot during the daylight hours, returning them inside for nighttime. Repeat this process until the weather warms enough to keep them outside over night.

Plants that look pale and leggy indoors may need more light. You can provide this with a simple grow light bulb. See more information about tools and supplies below.

Direct sowing

If you prefer to sow your seeds directly outdoors, you can go ahead and prepare your soil. You’ll still need to check the planting dates on each of your seed packages to avoid planting too early. You also have a few choices about how you sow your seeds.

• Broadcast seeding: Scatter seeds evenly across a prepared bed for dense coverage, covering lightly with soil. This method helps your vegetables outcompete weeds early in their growing cycle. Depending on the crop, you may need to thin once your seedlings have taken hold, but thinnings often go well in salads.
• Row seeding: The classic gardening approach, sowing seeds in rows, allows space for mulching and laying drip irrigation. Row seeding also works well if you like to hoe between rows for weed control.
• Square foot gardening: Rather than planting one variety of vegetable in a bed or row, consider switching things up! Square foot gardening sees multiple varieties planted intensively in a space of twelve inches square. You can use a seeding square to help.

We find a combination of starting plants indoors and direct sowing to be the perfect method for most climates.
 

What should (or shouldn't) you grow from seed?

Believe it or not, there are some plants that are tricky to start from seed and some that are so easy, they’ll grow no matter how much you neglect them. Here are some general rules of thumb to help you know the difference.

• Most leguminous plants (peas, beans and lentils) grow vigorously when directly sown. While you can start these plants in seedling trays, they’ll outgrow them quickly, keeping you on your toes.
• Sow root crops directly into garden beds. Transplanting a taproot from a seedling tray is not easy, nor is it necessary. Sow these crops directly in rows or broadcast seed for better coverage.
• Opt for vegetables over fruits. In general, growing fruits like strawberries, blueberries, and raspberries from seed is challenging and more time consuming than finding divisions or plants. Adding years to your harvest timeline isn’t usually necessary where these other options are available.
• Grow annual herbs from seed and perennial herbs from cuttings, plants or divisions. The easiest herbs to grow from seed include basil, fennel, cilantro, parsley, chervil and dill. Other herbs, such as rosemary, oregano, thyme, winter savory, and other perennials are more easily propagated from cuttings or divisions.
• Start brassica seeds indoors in cold climates. Help cabbage, cauliflower and broccoli reach maturity by starting these seeds indoors six to nine weeks before your last frost date. For kale, start indoors four to six weeks before your last frost date or sow directly in midsummer. Arugula is best sown indoors two to four weeks early or sown directly into garden beds.
• Start heat-loving crops indoors. Cucumbers, eggplants, tomatoes and peppers are all great candidates for starting in seed trays or plugs well before the weather warms. Pot up to larger pots as soon as their roots reach the bottom of the tray, then transplant out when nighttime temperatures no longer dip below 50 F for tomatoes and eggplant, and 55-60 F for cucumbers and peppers.

What supplies do you need for seed-starting?

The tools and supplies you’ll need depend on where you start your seeds. See below for items specific to your seed-starting location.

Indoor seed starting supplies

• Seedling trays: Usually made from plastic, seedling trays can be used repeatedly for up to a decade when cared for. Wooden trays are also an option.
• Soil plugs or blocks: Soil plugs come dehydrated in packages. When you add water they expand into a mini ‘pot’. Unfortunately, many have a plastic coating around their base, which takes a long time to disintegrate in the garden (if ever). Create your own soil plugs using a soil blocker and the appropriate soil mix.
• Seed starting mix: Young plants will perform best when they have the right mix of nutrients and moisture. Choose a seed starting mix that provides these elements, such as our DIY New Year’s starter mix, or buy a ready made product. Just be sure the package indicates “for starting seeds” or it may lack nutrients.
• Grow lights: Grow lights are usually only necessary in areas of low light. While seedlings grown in a south facing window may look leggy and weak until they get into the garden, they usually perk up within a few days once transplanted outdoors. Add a light where your seedlings get less than 10 hours of sunlight per day.

Outdoor seed starting supplies

• Finished compost: Adding finished compost to a garden is one of the best ways to condition your soil. In addition to adding nutrients, compost will improve soil structure and increase your soil’s water-retaining capacity.
• Organic all-purpose fertilizer: Most garden soil needs a dose of organic fertilizer at least once a year, to help replenish lost nutrients and give plants what they need to thrive. Mixing fertilizer into the bed or row before sowing helps distribute nutrients more evenly than top dressing.
• Soil test kit: Testing your soil every few years can help you better understand what nutrients your garden has in abundance and what nutrients might be deficient.
• Moisture meter: Keeping soil evenly moist as seeds are germinating is one key way to ensure success. A moisture meter can help you gauge how much water is at root level once your seedlings are established.

Problems growing from seed

Despite the best intentions, problems can arise when growing plants from seed. Here are some of the most common issues and their solutions.

Why won’t my seeds sprout?

One of the most common causes for seeds that don’t germinate is not enough consistent moisture in the soil. Keeping seeds moist during the critical germination period is easy with drip irrigation. For tiny seeds that take longer to germinate, consider using a corn starch gel during planting. The gel encases the seed, providing much needed humidity and moisture.

Another reason your seeds may not germinate is that they are too old. Most seed companies list average seed life on the package. Check to make sure you’re not using seeds that have passed their viability date. Take care not to bury your seeds too deeply, as this can also prevent seeds from reaching daylight.

Why are my seedlings falling over?

Seedlings can grow and fall over for a few reasons. If they don’t have enough light, they can get leggy and weak, causing them to buckle and droop. Move them to a brighter area or add a grow light for even better results.

If you notice a thinning stem near the soil, like something has pinched off your plant at its base, it’s likely to be damping off. Damping off is caused by soil fungi, and once it strikes, it’s hard to treat. The best way to prevent damping off in seedlings is to use sterile potting mix and sterilized (if re-used) seedling trays and pots. Water plants from the bottom and avoid cool, wet environments (70 to 75 F is best).
 

Why did my seeds come up and then disappear?

Seedlings that germinate and then vanish have become the victims of nearby pests. Often looking closely will reveal clues. Is there a trail of slime? Slugs are the culprit. Check in and around your seedling trays (including underneath, where slugs like to hide) and remove any you find. If the problem persists or you can’t find a cause, cover your seedlings with insect mesh or floating row cover.

I’ve transplanted my seedlings outdoors, but they’re not growing.

Patience is a virtue, and that rings true in this case. When moved from the warm indoors to the cold soil outside, transplanted seedlings can often go through a transition period. While your kale may look shocked–even yellowing at the edges for a few weeks–it will usually come around as long as the weather continues to warm and it receives enough water. If growth doesn’t pick up when the warm days arrive, consider a soil test to see what nutrients might be lacking in your garden.

Why are the tips of my seedlings turning purple?

If purple leaves accompany the stalled growth above, your soil likely has a phosphorus deficiency. Perform a soil test to be sure, but adding bone or fish meal should give your plants what they need in the short term. Adding rock phosphate will help boost phosphorous levels for the long term, up to five years. If the problem persists, it’s worth testing your soil’s pH, since phosphorus is less available in soils with a high pH.