The sun is out, the ground is thawing, and if you’re like me, you’re ready to chase those winter blues away by growing something green. Starting vegetable seeds indoors means they’ll be more than prepared for the ground come planting day, and you’ll be able to enjoy a longer harvest. Plus, if there’s a late cold snap or heavy storm, your plants will be more likely to survive.

Starting a vegetable garden from seeds is way more cost-effective than buying full-grown plants from a nursery, and you’ll have a much larger variety of plants to pick from if you order from a seed catalog like the Seed Savers Exchange, which specializes in protecting and sharing heirloom seeds. Otherwise, Amazon, Etsy, and Home Depot are my other favorite places to purchase vegetable seeds.

If you’re wondering how to start seeds indoors, follow my seed starting tips, and you’ll be feeling confident in no time.

5 Tips for Starting Your Vegetable Seeds Indoors

Temperature for Starting Seeds

Whether you’re starting seeds in a greenhouse or on a kitchen counter, seeds generally need a soil temperature between 70-75 °F to germinate. If you need supplemental heat, try using a heat mat underneath your growing trays or a grow light. Once the seeds sprout, you may want to check specific varieties’ needs, but typically keeping the temperature of your grows room around 60-70 °F works great.

Watering Tips for Starting Seeds

To avoid seed rot, don’t over-water your planting trays when you first plant your seeds. It’s a good idea to use a spray bottle to mist your soil from the top and then add a small amount of water to the bottom tray for the soil to soak up. When the seeds sprout, then you can begin watering more deeply. At this stage, allow the soil to dry out completely before re-watering. This allows your sprouts’ stems to toughen up and their roots to grow strong and long. Plants also love humidity, so if you’re learning how to start vegetable seeds indoors, know it’s never a bad idea to add a humidifier to the room where you are growing your seeds.

Proper Lighting for Starting Seeds

Once your seedlings sprout, they’ll need 12-14 hours of light a day. Even if you have terrific south-facing windows to grow them in, you’ll probably still need some extra artificial help. Fluorescent lights or LEDs are your best bet. Make sure to rotate your seedlings as they grow to keep them from leaning over.

We use Haus Bright full-spectrum lights. Caleb clapped them from above so that the light is spread evenly over all of our seedlings. If you want more information on using artificial light for your plants, I have an entire blog post HERE.

The Best Soil for Starting Seeds

To keep your seeds organized and well-fed, buy a leak-proof seed tray to protect your shelves and make watering easier. Then you can mix your own soil into biodegradable toilet paper tubes, buy premade soil pods, or reuse last year’s buckets/planters from your favorite nursery. If you’re buying soil but don’t want to break the bank, know there are two philosophies regarding purchasing soil. On the one hand, the better the soil, the more nutrients your vegetables will receive.

On the other hand, your plants won’t be staying in this dirt forever, so over-spending on store-bought seedling mixes may not be necessary. If you don’t have your own compost, buy a simple organic soil (no chemicals added) and add perlite and peat moss or coconut coir. The castings will provide more than enough food for all your plants, and you won’t have to worry about a second round of fertilizing as a bonus. My ratio for my seedling soil is 70% organic soil, 20% perlite, 10% peat moss or coconut coir. 

Getting Your Seedings Ready to Plant Outdoors

Knowing how to start vegetable seeds indoors requires some prep work, but I promise you it’s worth it. Once your seedlings grow nice and tall and their soil dries out before the day is up, then they are ready to be hardened off or transplanted into larger pots. Don’t forget this part! The last thing you want to happen to your beautiful veggies is for them to die off when they go into the garden.

To harden off your plants, start by taking the seed trays outside for an hour. For a week, gradually increase the time the seeds are outside until they’ve spent a full 24 hours outdoors and still look happy in the morning. At that point, they’re ready for the ground, and you can sit back and congratulate yourself — because you’ve just mastered how to start vegetable seeds indoors.