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Seed Planting & Spacing Information

By Jack S. Waverly ; Updated September 21, 2017
Proper seed planting and spacing ensures success.

The most important part of growing plants is the beginning--the seed. Many things must be achieved to ensure proper seed germination and plant growth. This begins with proper seed and site selection, followed by preparation of the seed and soil and finished with the planting of the seeds or transplanting seedlings. The initial germination and growth process is the most difficult portion of growing plants. Once this occurs successfully, many problems are eliminated.

Selecting Seeds

High-quality seeds are important to help ensure success of the garden. Seeds from large general retailers often are poorly handled or stored. A good option for quality seeds is to purchase from catalogs or online from reputable seed dealers. Selecting packets with planting information helps eliminate mistakes after purchasing; information should include the plant size, color, foliage or fruit, growth habit, spacing requirements and time line from seed to adult plant. Another option is to use seeds saved from the previous year's growth. This method is reliable only for heirloom seeds and not recommended for hybrids. Only keep seeds for one year to ensure they will germinate, according to North Carolina State University. The University also recommends keeping any seeds in air-tight packages or containers stored in low humidity and at a temperature of 40 degrees Fahrenheit.

Selecting a Site

Site selection is equally important for successful gardens. The amount of sunlight isn't the only consideration for a garden spot; soil composition, pH level and drainage all play a part in the location choice. Annuals usually require a pH range of 6.0 to 7.4, while perennials grow in the range of 6.5 to 7.0 pH. Depending on the plant, sandy or clay soil may suffice, although loamy soil is best. Working in a few inches of compost, fertilizer or mulch helps create suitable soil; this process is called ammending the soil. Breaking up the soil to a depth of 6 to 12 inches will help create adequate drainage so the roots don't drown or rot. This also keeps dangerous bacteria and fungus from finding their way to the roots.

Preparing to Plant

Preparation to grow seeds should be started either in the autumn or winter of the previous year. Preparation begins by choosing the medium used to germinate seeds. The growing medium should be a fine, uniform consistency. The medium needs to be sterile, meaning it is free of insects, nematodes, weed and weed seeds, bacteria and fungus. Commercial potting soil with fine pine bark or peat moss added is suitable. Garden soil is to be avoided because of its heaviness and poor drainage and it is not sterile. Cell packs or starter boxes are used to hold individual seeds during the germination process. Using cell packs or starter boxes keeps the roots from damage when transplanting the seedlings to their permanent locations. Starter boxes and cell packs can be purchased or created out of items like milk cartons or paper cups. Drainage holes need to be included in starter containers to ensure good drainage.


Planting seeds is a two-step process. Early indoor planting will lengthen the growing season and create a more viable climate for germination. North Carolina State University suggests starting seeds no sooner than four to six weeks ahead of expected transplanting dates. The seedlings will have their first true leaves within three weeks after seeding, after which they can be moved out of the starter boxes. Some seedlings may require transplanting to interim containers (such as plastic cups or larger planters) and being placed near windows with direct sunlight. Be aware that some plants don't transplant well.


When moving seedlings to permanent locations or starting seeds directly in the ground, spacing is important. Spacing relates to both the distance between seeds or plants and the distance between rows or hills of plants. Seed packets will have this information printed on them. The reason for adequate spacing is to allow the root systems room to grow. Grape vines require a 5-foot space between plants and 9 feet between rows, while sweet corn can grow 1 foot apart with rows spaced 3 feet apart. Small vegetables such as beans can grow within inches of each other with rows 2 feet apart. Overseeding occurs when smaller seeds cannot be spaced individually but are better scattered along the row. Thinning is the process used after these seeds sprout to remove excess plants and ensure successful growth of the remaining plants.


Watering is an essential element of successful seed germination and seedling growth. The soil used must be damp when seeds are sown. The surface of the soil must remain moist until the seedlings sprout; this often requires daily watering of the soil. Seedlings will need moist soil but not as much as seeds. Most seedlings can be watered biweekly unless the soil becomes dry faster. As plants grow, the amount of water will remain constant, but the number of waterings will decrease, meaning less frequent but longer waterings.