Peat pots are the simplest solution. Just add water to expand the pellets, then sow seed. Learn more about peat pots. You can also buy biodegradeable peat cell packs, pictured, with detachable cells that are planted in the ground when seedlings mature. Other options: Reuse plastic nursery containers or cell packs, as well as cups, yogurt containers, or milk jugs (be sure to add drainage holes if they’re missing).
This is more than just a fancy name for dirt. It’s a special mix that provides the ideal medium for seeds to set root. You can buy a prepackaged seed-starting mix or make your own with equal parts peat moss, vermiculite, and perlite. Don’t use topsoil—it’s too heavy for seed starting in containers.
Use fresh seeds, which have the best rate of germination. Older seeds have a lower germination rate, so spread them more thickly to compensate. Check the seed packet to see when and how to plant. Some seeds, such as peas, should be soaked first. Others need to be covered lightly with soil mix. Start most seed varieties six to eight weeks before transplanting outdoors.
Planting Seeds Indoors
If reusing old cell packs, scrub them with soap and water, rinse, dry, then spray with a 10-percent bleach solution to kill pathogens. Fill the cell pack with premoistened seed-starting mix and tamp gently to remove air pockets.
Sow seeds following packet directions. Large seeds, such as beans and peas, can be placed by hand while medium-size seeds are easily handled with tweezers. For tiny seeds, such as lettuce or basil, use a folded piece of paper and a toothpick to distribute seed more evenly. Press in larger seeds, lightly cover smaller seeds with seed-starting mix. Do not cover too deeply.
Keep the soil damp, not wet. Use a spray bottle so you don’t wash the seeds out of the soil. Seeds need warmth to germinate. Place on top of a refrigerator to capture ambient warmth from the appliance. Or cover the seed tray with a clear plastic lid to produce a greenhouse effect. Germination takes anywhere from 2–10 days, depending on species.
Once seedlings germinate, place them near a light source, such as a south-facing window (rotate trays every few days so seedlings grow upright rather than toward the window). For optimum photosynthesis, place seedlings 8–10 inches beneath grow lights. Keep the lights on 14–16 hours a day, using a timer if necessary.
Thin seedlings when they are 2–3 inches tall and have developed a set of true leaves in addition to the tender growth that originally emerged from the seed. Select the strongest seedling in each cell and carefully clip off competing stems.
Feed weekly with a liquid soluble plant food diluted to quarter strength. Wait to transplant seedlings into the garden until danger of frost has passed. Ease the transition from indoor to outdoor conditions by “hardening off” seedlings. Set trays in the shade for a few days, then move them where they’ll gradually get a little more sunlight each day. They should be acclimated to the stronger light within a week.
Sowing Seeds Outdoors
Some plants are best seeded directly in the garden—often those with large seeds, such as peas, beans, squash, and corn. But small-seed carrots and radishes also do better when started outdoors. Here are some helpful tips.
- Choose a spot that drains well and gets plenty of sunlight.
- Prepare the soil by raking the area clear of leaves and other debris. Dig down to about 12 inches to loosen the soil. Add fertilizer, if needed.
- Make planting rows with a garden trowel or hoe. If planting seeds in groups rather than rows, use a pointed object such as a pencil to make indentations in the soil.
- Sow according to recommendations on the seed packet. Large seeds can be planted individually. Some seeds are quite small and can be mixed with a bit of sand and sprinkled over the area.
- Attach the empty packet to a stick at the end of the row to identify what is planted and serve as a handy reference.
- Keep the garden watered. Most plants do well with about an inch of water a week. Irrigate in the morning so foliage can dry before nightfall. Or use a soaker hose or drip irrigation system to direct moisture where it’s needed.
See how rewarding it can be to start your own plants from seeds.