When to Start Garden Plants Indoors

When to start garden plants indoors

Last Updated on March 11, 2024 by Kimberly Crawford

There is little information on when to start garden seeds indoors for the best results in outdoor gardening plants.

True gardeners are thinking and planning the spring garden in the dead of winter, while snow is covering the ground. January is the time to start planning, selecting, and maybe even planting some seeds for the upcoming springtime garden, depending on the zone.

Here are some simple suggestions for growing vegetable transplants from seed, so the plants will be ready when time comes to put them in the outdoor garden. A general rule is to start seeds indoors six weeks prior to the last frost-free date in an individual zone. Frost dates for zones can be located at the Farmers Almanac web site.

The Early Spring Garden

Early Spring Garden

  • Leaf Vegetables – lettuce, spinach, Swiss chard
  • Root Vegetables – Carrots, radishes, turnips, beets
  • Cole crops – broccoli, cauliflower, cabbage
  • Allium – onions, shallots, chives, garlic

All of these seeds can be planted directly into the spring garden soil; however, there is a huge advantage to planting seeds inside prior to the last freeze date. The seedlings will be ready to plant directly into the soil at gardening time with a head start on produce.

Using the “One Step” Process

Fill new or sterilized pots with a mixture of 50 percent peat moss and 50 percent vermiculite. Sit the containers in a tub or sink with water until the mix is fully saturated. After planting two garden seeds in each pot, keep the pots at 70-75 degree temperature for quick germination. A heating pad beneath the pots will add warmth.

Commercial grow lights set on a timer for 18 hours of light and six hours of darkness is preferable. Keep a thermometer available to regularly check temperature as the lights may need to be lowered or raised, depending on the intensity of the heat as the plants begin to grow.

After about six weeks, the seedlings will be large enough to go outdoors to the newly cultivated garden. When handling seedlings, never grasp the seedling by the stem and pull it from the pot. This will injure the delicate tissue of the stem and lead to disease and die-back.

What and When to Plant Outside

Asparagus plants

Very Hardy – Four to six weeks before the frost-free date

  • Asparagus, broccoli, cabbage, cauliflower, lettuce, onions, peas, radishes, spinach, turnips

Hardy – Two to four weeks before frost-free date

  • Beets, carrots, chard, mustard, potatoes

Not Cold Hardy – Plant on frost-free date or soon after

  • Beans, corn, tomato

Needs Hot Weather – At least a week after frost-free date

  • Cucumbers, eggplant, melons, okra, peppers, squash, sweet potato

Where to Plant

  • Seed directly in the garden all beans, beets, carrots, corn, cucumbers, melons, okra, peas, radish, squash, turnips.
  • Transplant to garden from indoors all broccoli, Brussels sprouts, cabbage, cauliflower, celery, eggplant, pepper, tomato.
  • Start indoors or outdoors all Chinese cabbage, leeks, collards, corn, cucumbers, kale, kohlrabi, melons, mustard, squash, Swiss chard.

After about four months of preparation, the bounty of the harvest will be a testament to hard work and careful watchfulness. Healthy and delicious meals prepared with home grown vegetables are beyond measure.

When to Start Garden Plants Indoors