Vegetables

Different types of vegetables require varying degrees of soil acidity. The acidity or alkalinity of the soil is measured by pH, and must be adjusted according to which crop will occupy that area. Generally, soils in moist climates are acid and those in dry climates are alkaline. A soil with a pH lower than 7.0 is an acid soil and one with a pH higher than 7.0 is alkaline. You can buy an inexpensive pH test kit at most nurseries, and many good garden centers will gladly test a soil sample for you. Once you have determined the pH you can amend the soil as needed. The pH requirements of different garden vegetables will determine what steps must be taken next.

Only after the site has been prepared, and the soil and conditioners mixed, watered well and settled should you test the pH of the soil. The tested soil should be dry. If a soil test reveals that you need to make corrections to your soil pH, you can use materials commonly available at your local garden center. If your soil needs to be more acidic, sulfur may be used to lower the pH. For raising the pH, lime is most commonly used. The amount of either material used will depend on the amount of change you need to make. The recommendations provided on the product label will help you determine how much to use. A general rule of thumb is to add 4 lbs. of lime per 100 sq. ft. of garden for every pH point below 6.5, or 1 lb. of sulfur per 100 sq. ft. for every pH point above 7.5. Sawdust, composted oak leaves, wood chips, peat moss, cottonseed meal, and leaf mold lower the pH, while ashes of hardwoods, bone meal, crushed marble, and crushed oyster shells raise the pH. The best way to adjust pH is gradually, over several seasons. Most garden vegetables do best on soils that are slightly acid and may be injured by the application of excess lime. For this reason lime should be applied only when tests show it to be necessary. If the soil is excessively alkaline, you may find that you are better off to build a raised bed using topsoil purchased from a nursery.

From: The Garden Helper

Jamie writes~
Fertilizer: What do tomatoes like? What do potatoes like? What do eggplants like? What do cucumbers like?

A. Fertilizers are used to add plant nutrients not adequately supplied by the soil. A soil test is used to determine the amount of nutrients in the soil. The soil test report will make recommendations for the amount and type of fertilizer and/or lime you need to add to the soil for optimum plant growth.

Spread lime and other fertilizer (evenly and uniformly) over the entire garden area. Soil type dictates the frequency of fertilizer application. Sandy soils require more frequent applications of nitrogen and other nutrients than clay-type soils. Other factors affecting frequency of application include the plants being grown, the frequency and amount of irrigation, the type of fertilizer applied and its release rate. Root crops require less nitrogen fertilization than leafy crops. Corn is a heavy nitrogen-feeder, while most trees and shrubs perform nicely with one good application every year.

Clemson Extension has two very fine articles on the huge subject of fertilizing, which types, grades, at what rates, applications for different vegetables. Go to:

http://hgic.clemson.edu/factsheets/HGIC1654.htm
http://hgic.clemson.edu/factsheets/hgic1254.htm

Julles writes~ Some of the tomato and squash flowers fall off after they've bloomed. I always thought that the flower itself would hang on there and it would turn into the fruit. But if it falls off, will the fruit develop somewhere else? Doesn't it develop from the flower, and the seed-producing stuff inside the flower? So wouldn't the flower need to remain attached to the stem long after it finished blooming?

A. The flowers need to stay on the vine through pollination by bees, flies or other insects. Then, once that has been accomplished, the center ovule starts to turn green and enlarge. Then, the flower can drop off as it is no longer necessary for the growth of the fruit. It was there to supply the pollen [male] and to attract insects to the inside to spread the pollen onto the sticky stigma part of the female which leads down to the ovary.

Blossom drop is the loss of flowers. This is usually preceded by the yellowing of the pedicel. Flowers may either fall off or, as with jointless varieties, whither and die. Tomato plants lose their blossoms for several different reasons usually related to some kind of stress. The stress may be either nutritional, environmental or some combination of the two. However, anything which would interfere with the pollination-fertilization process may result in flower loss.

There are several possible causes:

Nutritional causes:

Nitrogen plays a key role in blossom drop. Too much or too little nitrogen will result in the loss of flowers. Many gardeners over-fertilize. Unless one has sandy soils or they are trying to produce record breaking fruit, there is no need to fertilize every week.

Environmental causes:

Temperature - Excessive temperatures (low or high) will produce blossom drop by interfering with the pollination or fertilization process. Generally, day temperatures above 90F or night temperatures greater than 70-75F will interfere with fruit set resulting in the loss of flowers. Research has indicated that higher night temperatures have more of an influence.

High Humidity - can effect either the release of pollen from the anthers or the adherence of the pollen grains to the stigma.

Other potential sources of blossom drop:
Excessive wind
Stress related to insect damage - (usually thrips or aphids)
Stress related to foliar disease
Lack of adequate light
Extended light exposures - (24 hour exposure to a light source)
Excessive pruning

Solutions:
To prevent blossom drop from occurring always ensure proper nutrition and follow good cultural practices which reduce potential stresses such as foliar diseases or insect problems. Generally a well balanced fertilizer mixed into the soil before planting and a follow-up application just after fruit set is all the nitrogen needed under most conditions. You can get around the heat issue by choosing heat tolerant cultivars or, as in some cases, overhead watering can help (note - overhead watering may not always be a good idea as it can encourage many foliar diseases).

Assistance from: http://www.kcinter.net/~tomato

Q. When should I dig up my sweet potatoes or yams?

A. You can begin harvesting your sweet potatoes as soon as the leaves start to yellow, but keep in mind that the longer they are left in the ground, the more vitamins they will have.  After a frost or two, the vines will turn brown. The tubers should be harvested as soon as possible to prevent rot.

On a sunny day when the soil is dry, use a fork spade to dig them.  As with white potatoes, the tubers can grow out as much a foot from the plants, so allow space when digging to avoid slicing them in pieces, as this will encourage spoilage.

Dry your harvest in the sun for a few hours, then bring them indoors and continue drying in a warm, humid place for a couple of weeks.  An open area of in the kitchen is a perfect spot for drying them. As the tubers cure, the starches are converted t o sugars. Properly cured sweet potatoes will last for several months. For long storage, wrap individual tubers in dry newspaper and store them in a cool, dry basement.

Ladydebayou writes~ what kind of soil or just tell me how to start vegetable plants indoors so I can have them ready for spring.. I tried potting soil but after so long, the bottom of the stem gets real small.

Use a commercially prepared propagation and transplant mix consisting of peat moss, vermiculite, perlite [and possibly pine bark], lightweight, free from plant pests and soil-born diseases, and drain very well. The result is far superior compared to garden soil when placed in small transplant-growing containers. Many efforts at producing homegrown or windowsill transplants result in far less than the gardeners expectations because of poor light. Unless you have a solar room with overhead sunlight or a greenhouse, chances are your window light, except for brief periods on sunny days, is too shady. Most days are cloudy, many are rainy or even snowy. Shady or one-sided light will not grow stocky vegetable transplants. For better results, use fluorescent lights placed about 12" above the seedling trays. The lights should be on a timer to provide 16 hours of bright light each 24-hour period. Dual fluorescent tubes provide stronger and more uniform light than a single tube. One cool-white and one warm-white fluorescent tube provide an excellent balance of usable light for photosynthesis. As plants sprout and grow under lights, these warm tubes should be raised so as not to produce too much heat too near the tops of the plants. To compensate for this warmth, keep plants growing on the cool side to promote stocky versus succulent growth. Best results may be accomplished by turning down to 55F all other heat in the plant room. A cool basement is an excellent area for starting plants under lights. If a warm room is used with its own heat source keeping normal air temperatures in the 70s, the addition of fluorescent growing lights over seedling trays will provide too warm an environment. Temperature for germination should be higher than for growing sprouted seedlings. After good 80F germination, 60F is preferable for growing most vegetable transplants to keep them stocky and healthy. Keep containers covered with plastic, clear glass, or plastic wrap, until seedlings begin to sprout. When plants are about 4" tall, they are an excellent size for least transplant shock and for faster regrowth in the garden, as opposed to plants that are 10-12" tall. When plants have reached 4" and are well-branched and stocky, they should be "hardened off" by reducing water and moving plants to an outdoor porch or coldframe for the final week before going into the garden. This will toughen them to the effects of wind and outside temperatures, and to the natural light/dark cycle. If an unexpected frost is forecast, move the plants back indoors under 16 hours of light, but keep the temperature at 55-60F.

Assistance from an article by: Charlie O'Dell, Extension Project Leader, Department of Horticulture, Virginia

LaydeBayou writes~
I would like to know what type of soil is best for starting my own vegetable plants. Last year I used regular potting soil and every one of my plants looked healthy and then they got real thin at the base, withered and died. I never had this happen before. Can you please tell me what I am doing wrong?

A. Whatever container you use, make sure that it has a hole through which excess water can drain. Any sitting water at the bottom of a container can rob growing roots of oxygen and encourage fungal diseases. If your seedlings succumbed to any diseases last year, make sure the containers are rinsed with a 10% solution of bleach to kill off any remaining spores. For potting mix, it is recommended to use a sterilized, soil-free starter mix to prevent diseases such as damping-off from taking hold of tender seedlings. Soilless mixes are totally free of any nutrients whatsoever. While young seedlings don't require fertilizers until they develop their first set of true leaves, having fertilizers already in the potting mix means not to worry about feeding for at least 5-6 weeks and tends to produce healthier seedlings. Most soilless mixes are a combination of peat, perlite and vermiculite and drain very quickly, requiring frequent watering when seedlings produce first set of true leaves. Both sterilized compost and worm casts retain moisture and keep it available for growing roots. Overcome a past problem with damping-off or overwatering seedlings by watering from the bottom and using a sterile mix. Spindly and falling over seedlings may be due too low light, as early spring light just does not have the intensity and duration that young seedlings need, forcing them to stretch for more and more light. Most seedlings require 12-14 hours of direct light in order to keep them short and stocky and producing healthy leaves. Therefore, artificial lights are required early in the season. A combination of warm and cool fluorescent bulbs is effective. Since seedlings need high light intensity, these bulbs need to be no more than 3-4" from the top of the plant. If the lights are still too far away, you can also raise the trays on boxes. As the plants grow, the boxes can be removed so that the leaves do not touch the bulbs.

Assistance from: http://www.gardenguides.com