Water Management

Watering properly requires practice. When the plants are small it is easy to over water. Do not have plant containers on a tray with water standing in it. If you use a tray, top water the plants until some water begins to run out the bottom of the container and stop. Do not water again until the plants show a need for water. Water of suitable quality for household use is satisfactory for watering plants.

When a soilless growing medium is used, do not be misled into thinking the plants need water if the surface of the medium looks dry. This will normally occur before the moisture level in the root zone is low enough to result in moisture stress for the plant. A better method to determine when water is needed is to squeeze a sample from the top half inch of medium between the thumb and finger. If water squeezes out easily there is adequate water. If the medium feels slightly moist but water is very difficult to squeeze out, additional watering is needed.

If the plants are where one can observe them several times daily, a good method is to water only when slight wilting occurs. When watering, apply enough to completely soak the medium to the bottom of the container.

Do not water plants with very cold water. Water temperature should be as near room temperature as possible. Applying very cold water to plants on a bright day may result in wilting, stunting of growth, and injury to leaves.

The time needed to grow a plant to suitable size for transplanting will vary with the type of vegetable and the season.

Cucurbits should be direct seeded, 2 seeds per pot in the container they will be grown in to transplanting size. Usually 3 weeks after seeding these crops will be ready to set in the garden.

The other vegetables discussed will require 5 to 7 weeks, with perhaps as long as 8 weeks from seeding to transplanting for pepper and eggplant.

The stage of development is more important than size of transplant. Tomato, pepper, and eggplant transplants should be set in the garden at late flower bud to early bloom stage.

If fruits are present on the transplants, these should be removed. Otherwise development of the fruits will continue, resulting in a marked reduction in plant vigor and fruit production. Cucurbits should be transplanted when the first true leaf is 1 1/2 to 2 1/2 inches across.

Hardening Transplants

Some plant growers "harden off" vegetable transplants before setting them outdoors. You do this by one or more of the following: reducing growing temperature, withholding water, and increasing light intensity. Frequently this is done by placing the plants outside during favorable weather in the last 2 to 3 weeks before setting in the garden. Take the plants indoors if frost is expected. Water within a few hours after the plants start to wilt.

In no case should cucurbits be hardened. In most instances it is doubtful that hardening is needed for any properly grown vegetable transplant that is to be set in the home garden which has reasonably good protection from wind and blowing sand. It is much better to produce stocky, healthy, vigorous plants to set in the garden than to have tall, weak plants less able to withstand the rigors of growing in the garden.

Common Pests

One of the most common diseases the plant grower faces is damping off. This disease attacks germinating seeds and small seedlings, and may result in loss of an entire seed flat. The best way to combat damping off is to prevent the organisms causing it from being introduced to the plant-growing area. This may be done by using all new materials each year such as growing containers, media, etc. Also, take care in watering to Prevent excessive wetness. Do not use any non-sterilized soil or items contaminated with soil. If you use a hose to water the plants, keep the end of it off the greenhouse floor.

Plants that have been outside "hardening" and are ready for transplanting in garden.

Other bad news for transplants includes foliage diseases and soil-borne wilt diseases that may have been introduced if you use contaminated soil. These are not likely to be a problem if you give proper attention to sanitation and selection of disease-resistant vegetable varieties.

The most common insects likely to be encountered are aphids, white fly, and leaf miner. Often these are present on ornamental house plants, so one means of control is to disinfest house plants before starting the vegetable plants. Also, plants brought in from other greenhouses may be infested with insects.

Control begins with prevention to the greatest extent possible. If other plants in the area are infested with insects, either remove the plants or kill the insects with an approved material. Make sure that any plants brought in from another source are free of insects.

If an infestation occurs, determine what the insect pest is and use the proper insecticide at the correct rate for control. Observe all safety precautions with insecticides. Plants growing in the house should be taken outside for treating, weather permitting.

Insect control is also important for controlling certain diseases, especially virus diseases, which may affect tomatoes, peppers, and some cucurbits. Aphids often transmit these diseases from host plants such as weeds and some house plants to susceptible vegetable crops.