The Edmond Sun

January 23, 2014

Growing vegetable transplants

Ray Ridlen
The Edmond Sun

EDMOND — February is an excellent time to start your vegetable transplants. There are numerous reasons people start their own transplants. Earliness, economy of space and lengthening of the growing season may be obtained by transplanting many vegetables instead of sowing the seed directly in the field or garden. Moreover, with some kinds of vegetables, it is almost impossible to establish good stands from seed sown directly in the field or garden.

Growing transplants requires skill and care. Factors such as light, temperature, humidity, watering and the physical condition and fertility level of the plant-growing media must be considered.

Media for growing transplants may range from a completely artificial material, such as vermiculite or perlite, to field or garden soil. In most instances topsoil from the garden is not suitable because it dries out rapidly, becomes hard and lacks good physical condition.

There are many different soil mixtures suitable for growing transplants. Some standard “soil mixes” for plant growers are available. Some standard brands are: “Jiffy Mix,” “Redi Earth” and “Pro-Mix.” These mixes contain various proportions of materials such as peat, perlite, vermiculite and sand. These artificial mixes produce excellent transplants and growth is more uniform, rapid and easily controlled than in soil mixes. In addition, sterilization by the grower is not necessary when these commercially prepared mixes are used.

Two basic systems are used for starting seedlings:

1. Seeding directly in small pots or growing containers.

2. Seeding into flats and later transplanting into growing containers.

The first method involves less handling of the small plants. Growers who seed in flats and transplant into pots may do so because of space limitations. Vine crops (cucumbers, muskmelon, watermelon, pumpkin and squash) should be directly seeded into growing containers since they often will not survive if transplanted as seedlings.

For good germination the soil must be kept moist. To help maintain proper temperature and moisture for germinating seeds, the flats or pots should be covered with plastic until the seedlings break through the soil.

As soon as seedlings emerge they should be grown at a somewhat lower temperature than that required for germination. The soil surface should be wet only as often as necessary to keep the young plants growing.

Low light, excessive nitrogen and high temperature cause excessive stem elongation. Seedlings exposed to a high light level (full sunlight or artificial lighting) will mature quicker and produce higher quality transplants.

Gradually harden plants for a week before transplanting them into the garden. Hardening prepares plants to withstand conditions such as chilling, high temperatures, drying winds and water shortages. Withholding water, nitrogen fertilizer and moderately lowering temperature are the best ways to harden transplants. Avoid over-hardening transplants since this will cause the plants to resume growth slowly after being set in the field or garden.

RAY RIDLEN is an agriculture/horticulture educator for Oklahoma County OSU Extension Center, 930 N. Portland, Oklahoma City. He may be reached by calling 713-1125.