Remember the thrill of planting a seed as a kid and checking it every morning until it sprouted? Starting a garden from seed brings that same feeling back, and it's easier than it looks. In this guide, you'll learn what seeds actually need to germinate, how to start them indoors, and how to get your seedlings into the garden without losing them along the way.
What does a seed need to sprout?
Every seed is a tiny plant waiting for the right conditions. Most need just three things to wake up:
- Moisture: Seeds absorb water to start growing. Soil should feel like a wrung-out sponge, damp but never soggy.
- Warmth: Most vegetable seeds germinate best between about 65 and 85°F. Cool-season crops like lettuce and spinach sprout in cooler soil, while peppers and tomatoes want it warm.
- Air: Waterlogged soil smothers seeds. A light, fluffy seed-starting mix gives them the oxygen they need.
Light matters once seedlings are up. A few seeds, like lettuce, also germinate better with some light, which is why they're sown so shallowly. Always check the packet for planting depth.
Which seeds should you start indoors?
Not everything needs a head start. Here's a quick way to sort them:
- Start indoors: Slow growers and heat lovers like tomatoes, peppers, eggplant, onions and many herbs. These usually go in 6 to 10 weeks before your last spring frost.
- Sow directly outside: Crops that grow fast or dislike transplanting, like beans, peas, carrots, radishes, corn and squash.
Here in Minnesota, zone 5a, our last frost usually lands in mid-to-late May, so peppers and onions get started in March and tomatoes in early April.
How to start seeds indoors
- Use clean containers. Seed trays, cell packs or recycled yogurt cups with drainage holes all work.
- Fill with seed-starting mix. It's lighter and finer than garden soil or potting mix, so tiny roots push through easily.
- Plant at the right depth. A good rule is about two to three times the seed's width. Tiny seeds just get pressed onto the surface.
- Keep them warm and moist. Cover trays with a clear lid or plastic wrap until seedlings appear, then remove it.
- Give them strong light. A sunny window often isn't enough in early spring. A simple shop light hung 2 to 4 inches above the seedlings for 14 to 16 hours a day keeps them sturdy.
Caring for young seedlings
- Water: Water from the bottom when the surface feels dry. Overwatering is the most common way seedlings are lost.
- Air: A small fan on low strengthens stems and helps prevent damping off, a fungus that topples seedlings at the soil line.
- Feed: Once seedlings have their first true leaves, feed them with a half-strength liquid fertilizer every week or two.
- Pot up: If roots fill their cells before it's time to plant out, move them into bigger pots.
Moving seedlings into the garden
Seedlings raised indoors need time to adjust to sun, wind and cooler nights. This is called hardening off. About a week before planting, set them outside in a sheltered spot for an hour or two, then gradually lengthen their time outdoors each day. Plant them out on a cloudy day or in the evening, and water well.
Good first crops for beginners
- Large Leaf Italian Basil (about 60 to 75 days): sprouts quickly indoors and grows into big, fragrant plants. Lots of gardeners like to tuck it in near their tomatoes.
- Large Red Cherry Tomato (about 70 to 80 days from transplant): vigorous and productive. A great confidence builder for your first tomato.
- Black Seeded Simpson Lettuce (about 45 days): sow it right in the garden in early spring and you'll be picking salad in about a month.
Your first seeds are waiting
Starting from seed is part science and part patience, and every season teaches you something new. Grab a few packets, set up a light and enjoy watching that first green loop push through the soil. Our seeds are non-GMO and USA grown, and I pack each packet myself here in Minnesota.
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