The best seeds for starting indoors are crops with long growing seasons or slow sprouting habits. Think tomatoes, peppers, eggplant, broccoli, and basil. These plants need a head start to bear food before frost cuts them down.
My garden changed for good once I gave up on direct sowing tomatoes and peppers. The first year I tried, I tossed seed right into cold soil in May and got nothing. The next year I started indoor seedlings in March and had ripe fruit by August.
Vegetables to start indoors share a few key traits. They love warm soil, dislike cold roots, and take 70 to 100 days from sprout to harvest. Many short-season gardens just do not give them enough time outdoors.
Small-seeded crops like petunias and basil also do better inside. The seeds need tight moisture and warmth control. Out in the garden, a hard rain or dry spell can wipe out a whole batch in one day.
Warm-Season Vegetables
- Top picks: Tomatoes, peppers, eggplant, and tomatillos lead this group with great results from indoor starts.
- Sow window: Start these 6 to 8 weeks before your last frost so plants stand tall but not floppy at garden day.
- Why indoors: These crops need 80 to 100 days to ripen fruit, which most northern summers cannot offer outdoors.
Cool-Season Crops
- Top picks: Broccoli, cabbage, kale, lettuce, and cauliflower all transplant well from indoor cells into the spring garden.
- Sow window: Start 6 to 8 weeks before last frost so plants go out in cool weather and form heads before summer heat.
- Bonus tip: Sow a second round in mid-summer indoors for a fall crop that you set out in early September.
Herbs
- Top picks: Basil, parsley, chives, oregano, and thyme grow well from seed in a sunny windowsill or under lights.
- Sow window: Basil wants 6 weeks of indoor time. Parsley needs 10 to 12 weeks since seeds sprout slow.
- Pro move: Pinch tops at 4 inches tall to push bushy growth instead of leggy single stems.
Flowers
- Top picks: Marigolds, petunias, snapdragons, zinnias, and impatiens transplant well after an indoor start.
- Sow window: Most flowers want 6 to 10 weeks indoors. Petunias and snapdragons sit on the longer end.
- Light needs: Flower seedlings need bright light or they stretch fast. A shop light over the tray works fine.
If this is your first try, pick just 2 or 3 crops to start. I tell new growers to begin with tomatoes, basil, and marigolds. All three sprout fast, grow strong, and pay you back with food or color by midsummer.
Order fresh seed from a known supplier each year. Old seed loses vigor and gives weak sprouts that often die before transplant. A fresh packet of tomato seed costs about 3 dollars and gives you 30 to 50 plants.
Keep your list short the first season. You can scale up next year once you know what your space and time can handle. A small batch of strong indoor seedlings beats a tray full of weak ones any day.
Read the full article: Starting Seeds Indoors: 10 Steps for Success
