Weekly Express-News Article

By Calvin R. Finch, PhD, SAWS Water Resources Director, and Horticulturist

Saturday, September 6, 2008

“Basics of Vegetable Gardening”

            The increase in food costs and high gasoline prices have encouraged some families to consider growing some of their own vegetables.  Gardening is an activity that can be done at home, is good exercise, is fun and can be productive.

             Fall is my favorite vegetable growing time.  It is pleasant to be outside and there are great vegetables to grow including broccoli, cabbage, carrots, spinach, lettuce, turnips, rutabagas, radishes, cauliflower, chard and mustard.  Tomatoes, beans and peppers should be in the garden right now.  They produce until cold weather arrives.

             The best way to grow vegetables in the San Antonio area is in a raised bed.  Select an area in full sun and border the garden with used railroad ties, treated wood, rock, plastic timbers, cedar lumber, concrete blocks or anything else that will contain at least eight inches of soil.

             I like use railroad ties the best, because they are heavy enough to stay put without fastening or staking.  Local research has determined that they are safe to use to border the garden and they are readily available in eight foot lengths at a reasonable price.

             The site should be relatively level, but does not need to be fanatically so.  Use your shovel to remove humps or fill dips that prevent the timbers from sitting firmly on the ground.  I like a garden that is eight feet wide, because you can reach in from both sides to the middle without having to stomp through the garden.

             One railroad tie deep is suitable if you have some native soil.  If your garden is placed on rock or it could be built taller.

             Wheelchair gardeners also benefit by taller raised bed gardens.  Build the garden tall enough that the gardener can reach in from the side while sitting in a wheelchair.  In the case of a wheelchair garden, the width can be reduced to four feet to facilitate working the garden from the side.  There is considerable information on handicapped gardening on the internet, just Google the topic to find specific garden plans for various limitations.

             Purchase raised bed garden mixes from one of several horticultural suppliers in the area.  The list includes Keller Material, Fertile Garden Supply and Garden Ville.  The garden mix usually is made of one-third compost, one-third soil and one-third sand.  Avoid mixes that are obviously dominated by sawdust.  The material causes a nitrogen deficit and is not useful in the garden.

             Even the best soil mix is low on nitrogen so add one cup per 50 square feet of slow release lawn fertilizer as a pre-planting preparation.

             Vegetables are not xeriscape plants; they produce a good crop only if they receive plenty of water.  Drip irrigation is the most efficient way to provide water.  Newly planted vegetables need water everyday and vegetables with fruit, greens or roots require water at least twice per week if you are going to harvest a large crop of tender, well formed vegetables.  Mulching with oak leaves or other materials also helps.

             Irrigation contractors can put your drip system in for you or you can do it yourself with kits or supplies from nurseries and home improvement stores.  For an inexpensive short term drip system, leaky hoses can be strung out in the garden.

             After sun, soil and water, successful home vegetable gardening does require some attention to timing, pest control, fertilization, thinning and harvesting.  Grow cool weather plants in the fall and winter and hot weather plants in the spring and fall.  Each vegetable has one or more recommended planting time to take advantage of the weather it needs.

 Timing is also important for disease and insect control.  Some pests are only prevalent in the spring and some are more likely at other times.  In addition, there are a wide range of organic and manufactured pesticides to utilize.  Some vegetables do very well without much attention to pests and others require considerable attention.

 For maximum production vegetables need generous supplies of nutrients.  Tomatoes and greens are especially dependent on fertilization.  They are fertilized at planting and then every three weeks along the row.  Slow release lawn fertilizer seems to be the best choice for vegetables in the garden.

 It is sometimes hard to do, but vegetables need to be thinned.  The plants need to have space to grow to produce to their full potential.  The space requirements range from two or three inches for radishes, six inches for bulb onions, 2.5 feet for tomatoes to eight feet for vine crops.

             For more information on the cultural practices to grow good vegetables follow columns like this one, the gardening shows on radio and internet sites like plantanswers.com.  Local gardening media outlets usually alert gardeners to current problems and solutions in addition to general information on planting and care.