Home Gardening

Vegetable harvest is not far away
Mississippi Gardens Newspaper and Web Column - May 3, 2004

Home Grown Vegetables

May is a great time to be vegetable gardening. Snap bean, squash, sweet corn and Irish potato harvest is not too far away if they were planted early. Irish potatoes are harvested as soon as they are large enough to eat. However, the main crop is harvested after the vines have yellowed. Multiplying onions that over-wintered can be pulled, sun dried and saved for replanting in August.

Hopefully, the tomatoes are faring well and setting small fruit. Many times, though, young fruit will develop a blackened area on the underside (blossom-end) of the fruit. This usually occurs this time of year and is known as Blossom End Rot. It can be devastating to tomatoes. Unlike other diseases, blossom end rot is caused by a calcium deficiency rather than by fungi, bacteria or virus.

Calcium is supplied to the tomato in water absorbed from the soil by roots. Through a series of plant processes, calcium and other nutrients ultimately find their way into the fruit. However, even with adequate calcium in the soil, blossom end rot can be brought on by anything that interrupts this flow of water in the plant such as drought or soil flooding. Preventing moisture stress is therefore key to minimizing Blossom End Rot.

Usually, in garden soils with adequate calcium, plants will eventually produce normal fruit. That is, it's usually only the first two clusters or so of fruit that are affected. The recovery may be due to increased soil temperature and an increase in the size of the plant's root system.

Some gardeners use liquid calcium chloride sprays on their tomato leaves in an attempt to prevent blossom end rot. However, calcium does not move into the fruit very easily by this method. The best way to get plenty of calcium into the tomato plant is to keep the soil evenly moist, provide good drainage (i.e. raised beds) and keep soil calcium levels up by adding lime based on soil test results. Affected fruit should be pulled and discarded.

Wilting Tomatoes

The tomato is obviously the most popular garden vegetable. Yet, raising tomatoes can be quite difficult due to the number of pests and environmental factors that work against even the best tomato growers. For instance, there are at least seven factors that cause tomatoes to wilt. These include diseases like Fusarium, Bacterial Wilt, Southern Blight and Tomato Spotted Wilt Virus. They can also be attacked by Nematodes, which are tiny parasitic worms. And, of course, too much or too little water can cause wilting.

Probably the most heartbreaking of these wilt causing agents and the least preventable is bacterial wilt. Tomatoes with this disease wilt rapidly and rarely recover. Some describe the affected tomatoes as looking like they had hot water poured over them. The deadly bacteria that causes the disease fills the plants plumbing system to the point where water flow is cut off and the plants wilt and die.

When bacterial wilt affects tomatoes one year we are generally assured that it is there to stay. It's therefore best to find a new garden spot, or to raise tomatoes in containers. Containers should not be in direct contact with infected garden soil.

For more detailed information on tomato diseases and other gardening info contact your local Mississippi State University Extension Service office.

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These archived columns were written by Kerry Johnson, a hobby gardener, former weekly newspaper columnist and an Area Extension Horticulture Agent for 11 coastal counties in Mississippi.