Start plants from seeds now

Daniel Gill, Bogren, Richard C.  |  2/14/2008 2:46:51 AM

Get It Growing News For 02/01/2008

By Dan Gill
LSU AgCenter Horticulturist

At some point, many gardeners discover there is a much greater selection of annual flowers and vegetables available in seed catalogs than can be found at local nurseries. To grow those wonderful plants, however, you must be able to grow your own transplants from seed.

Containers for sowing seeds

One part of facing that challenge is selecting the right containers for sowing seeds.

Containers should be clean and sturdy, have drainage holes and fit into the space available for growing the young plants.

Seeds may be planted thickly into plastic flats, trays, pots or other handy containers for later transplanting into small individual containers. Starting seeds this way initially saves space but involves additional labor transplanting the young seedlings into individual pots when they are large enough.

If you prefer, you can plant seeds directly into individual pots. Small clay or plastic pots, plastic cell packs, peat pots or foam or paper cups (punch holes for drainage) may be used.

Growing media

The medium used for starting seeds should be sterile, well-drained and of fine texture. Excellent commercially prepared mixes are available for growing seeds. Light, well-drained potting soils also will generally be satisfactory, especially with larger seeds. But do not use garden soil.

Planting seeds

Fill the container almost to the top with moistened medium, level it and gently firm it with your hand.

Scatter or broadcast the seeds evenly over the surface. If planting in individual pots, plant two or three seeds per pot (all but one seedling will be pinched off if they all germinate). With larger containers, sow a number of seeds fairly thickly and transplant the seedlings into individual pots later.

Lightly cover the seeds to the depth recommended on the seed package. Very fine seeds need not be covered. Label each pot promptly with the plant type, cultivar name and planting date.

Water the seeds in with a fine spray, being careful not to flood the container. Then water as needed to keep the medium evenly moist but not soggy. Never let it dry out!

Place the container in a warm location, but light is not critical at this point unless the seeds need light to germinate. Generally a temperature range from 65 degrees to 75 degrees is best. Gentle bottom heat can speed germination and can be provided by special heating cables available at nurseries or by mail order. If the weather is warm, the containers may be placed in a shady spot outside.

Watch daily for germination. The seed package should indicate the number of days required. Move to bright light as soon as germination begins. This is very important. Also, water regularly because seedlings will quickly die if allowed to dry out.

Growing the seedlings

Light is especially critical once the seeds germinate. If the seedlings begin to stretch and look leggy, they are not getting enough light.

Grow the seedlings in a sheltered location outside in spring, summer and fall when conditions are warm enough. Seedlings of sun-loving plants should receive about six hours of sun each day. Seedlings of plants that prefer shadier conditions should receive two or three hours of morning sun.

It is common to start seeds indoors this time of year when it’s chilly outside. Place the containers of seedlings in the sunniest window you have.

If you don’t have a sunny window, you also can successfully grow seedlings using a fluorescent utility light fixture suspended on chains from hooks. Position the fixture 3 inches above the seedlings and leave it on 14 hours to 16 hours a day. Raise the fixture as the seedlings grow.

Whether inside or outside, water regularly and fertilize seedlings once a week with 20-20-20 soluble fertilizer mixed half strength.

As soon as the seedlings are large enough to handle, they should be carefully separated and transplanted into individual pots – or if already growing in individual pots, thinned to one plant per pot. When transplanting, always handle the small seedlings by a leaf because their thin stems break easily.

Planting into the garden

When plants are large enough – they need not be in bloom – plant them into the garden when weather conditions are suitable.

But remember, plants grown indoors or in greenhouses need to be acclimated to the environment outside before planting. First, place them in a protected shady location and allow them to wilt slightly before watering. Then, over the next 10 days, gradually expose them to more light.

Plant transplants into well-prepared beds at the same level they were growing in the container and space them according to recommendations on the seed package.

Congratulations! You have just entered a new and wonderful phase of gardening.

Get It Growing is a weekly feature on home lawn and garden topics prepared by experts in the LSU AgCenter. For more information on such topics, contact your parish LSU AgCenter Extension office or visit our Web site at A wide range of publications and a variety of other resources are available.


Contact: Dan Gill at (225) 578-2222 or 

Editor: Rick Bogren at (225) 578-2263 or


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