Some seeds shouldn't be started indoors no matter how eager you are to get growing. Certain plants grow taproots that push straight down into the soil. Moving them kills or stunts that main root. Other seeds sprout and grow so fast that indoor starting wastes your time. These crops do best when you plant them right where they'll stay.
I tried starting carrots indoors my second year of gardening. The seedlings looked healthy in their little cells. But when I dug them up at harvest, every single root had forked or twisted. Meanwhile the carrots I direct sowed in the same bed grew long and straight. The direct sow only seeds lesson cost me a whole season of carrots before I learned it.
Root vegetables develop taproots that need to grow straight down without hitting any barriers. A seed tray cell forces the root to curl or fork before the plant ever reaches the garden. That damage stays with the plant for life. Carrots, parsnips, radishes, beets, and turnips all grow taproots. These seeds that hate transplanting must go straight into their final spot.
Large seeds like beans, peas, corn, and squash sprout within days of planting. They grow so fast that starting them indoors gives you almost no head start. By the time you harden them off and transplant, direct sown seeds have caught up. You add work without gaining time. Plus these plants put out extensive root systems that fill a small pot in days.
Cucurbits like squash, cucumbers, and melons sit on the fence. You can start them indoors if you're careful. But they grow fast and resent root disturbance. I've had better luck planting them outside once soil warms up. They catch up to indoor starts within two weeks and avoid the transplant shock. Most vegetables to plant outdoors in this group do fine with a late May or June sowing.
Prepare your outdoor beds before planting direct sow crops. Work the soil until it's fine and loose. Rake out rocks and clumps that could block tender roots. Water the bed a day before sowing. This gives seeds moist soil to sprout in without the risk of washing them out with heavy watering right after planting.
If you want an early start with these crops, use row covers instead of indoor starting. Plastic or fabric row covers warm the soil and protect young plants from cold snaps. You can plant direct sow seeds a week or two earlier under cover. The plants grow in place from day one and skip the transplant stress that sets back indoor starts.
Read the full article: How to Germinate Seeds: 7 Foolproof Steps
