1. Q. Occasionally green beans germinate and come up but only have two leaves or maybe none at all. What is wrong?
A. This condition is termed snake head or bald head and is generally caused by planting cracked or damaged seed. Occasionally the beans literally pull their heads off when forced to germinate and come through heavy or crusted soil. Planting high-quality seed and maintaining the soil in a relatively moist and friable condition will help eliminate this problem.
2. Q. What causes my plants to bloom but not set pods?
A. Excessive fertility often causes beans to bloom profusely but fail to set any pods. High temperature combined with low humidity can also cause beans not to set. Planted at the right time and without excessive fertility, most recommended varieties will produce a crop of high-quality beans. A light fertilizing after the first harvest will greatly increase subsequent yields and improve quality of later harvested beans. Beans must receive 8 to 10 hours of direct sunlight to produce maximum yields.
3. Q. Why are some types of beans able to climb and others are not?
A. Pole beans are characterized by an indeterminant or vining growth habit and bush bean varieties are determinant. In the vining type, flowers form in the axles of the leaves and stem, thus the stem may continue to grow indefinitely. In the determinant-type growth the main growing point terminates in a flower cluster, preventing stem elongation. Beans that climb do so by virtue of their twining stems. The absence of tendrils or tendril leaves in beans helps distinguish beans from peas. Pole beans cannot climb until they are well along in their growth.
4. Q. What causes garden beans to become tough, stringy and fibrous?
A. This problem is commonly caused by high temperatures when the pods are forming. Low fertility and inadequate moisture can also contribute to this condition. To produce pods of high quality and flavor, plant beans when they will mature before temperatures become excessively hot.
5. Q. Can I save seeds from this year's bean crop for next season's garden?
A. Since beans are self-pollinated, they will breed true from one year to the next. However, certain diseases can be seed borne and may appear in next year's garden if you plant seed from the previous garden.
6. Q. Can mung beans be grown in Texas gardens?
A. Yes. Seeds of the mung bean are the source of bean sprouts, an ingredient in many popular Chinese dishes. Plant them after all danger of frost in rows 3 feet apart with plants 3 to 4 inches apart in the row. The pods are ready to harvest when they are fully mature and dark brown in color. The pods will mature over a long time. The seeds should be removed and germinated under clean, moist, dark conditions to produce long, tender, nutritious sprouts.
7. Q. What is the "yard-long bean"?
A. The "yard-long" or asparagus bean is a close relative of the southern pea. It produces pods up to 3 feet long. The plants are vining and need support. The pods are tender when young and frequently used as snap beans. For this use, harvest them when the pods are partially developed and before seed enlargement shows. For shelling, harvest them when the seeds are full size, but still immature. They may also be shelled when fully mature.
8. Q. Can I grow soybeans in my home vegetable garden?
A. Yes. Soybeans are highly nutritious and produce fairly well in many areas of Texas. Certain varieties, commonly called vegetable soybeans, are milder in flavor than those grown in fields. They are normally eaten in the green shell stage. The pods should be thick when fully mature but still green and tender. In most areas of Texas seed them in May or June in rows 30 to 36 inches apart with plants 2 to 3 inches apart in the row.
9. Q. What is a broad bean?
A. Broad beans, also called fava, horse bean and Windsor beans, are not true beans. They are closely related to vetch and will grow in cool weather unsuited for green snap beans. Varieties commonly grown include Broad Windsor and Long Pod. They can be planted very early in the spring in all areas of Texas. In central and southern Texas, they can be planted in the fall for spring harvest. In most areas of Texas they will not produce in the heat of summer. The commonly grown varieties require from 85 to 120 days from seeding to harvest.
10. Q. The foliage of my beans turns yellow on top and forms a brown, dusty material on the bottom.
A. This is bean rust. It is caused by a fungus and is controlled with sulphur or chlorothalonil spray. Rust is associated with cool weather. Repeated applications are necessary. Begin at the first sign of rust.
11. Q. My bean foliage is distorted with a mottled pattern. The fruit is crooked and hard.
A. This is bean mosaic, a virus that is seed transmitted. Once it develops within a garden, it can be moved from one plant to another by aphids. Control this by using good-quality bean seed following an aphid control program in the garden and removing diseased plants.
12. Q. My beans came up to a good stand and then began to die.
A. This is seedling disease of beans caused by a fungus, Rhizoctonia. Control for this disease includes a combination of practices. The first is to plant on a raised bed so the soil does not stay wet around these plants and will warm-up faster. The only chemical that can be used for the control of this disease is captan. Apply it in the seed furrow at planting time. In areas where this disease has been a problem, rotation is essential. The disease will be most severe during early spring.
13. Q. My beans are very stunted. When I removed them from the soil, I found large galls or swellings on the root system.
A. These are root knot nematodes. Root knot is a species of nematode which causes galls or swellings on plant roots. It restricts the uptake of nutrients from the root system to the foliage, resulting in a yellow and stunted plant. Root knot lives in the soil and can survive on a number of weed and vegetable crops. It is best controlled by planting a solid stand (close enough for root systems to overlap) of marigolds three months before the first killing frost of fall and/or planting cereal rye (Elbon) for a winter cover crop. Cereal rye should be shred and tilled into the soil 30 days before planting a spring crop.
14. Q. My beans appear to be very healthy. However, in examining the root system, I find that the roots have small galls attached to them.
A. These are nodules formed by nitrification bacteria. All legumes have the ability to fix atmospheric nitrogen in their root system. Do not confuse these nodules with knots caused by nematodes. The nodules, caused by nitrification bacteria, appear to be attached to the root system whereas knots caused by nematodes are enlarged areas of the root itself.
15. Q. My bean leaves have large brown spots on them. The damage looks more severe near the soil. However, it is beginning to cover the plant.
A. Although a number of leaf spots occur on beans, one of the most severe in Texas is Anthracnose. It is caused by a fungus that is airborne. It can be controlled with chlorothalonil fungicide. Begin applications at first sign of the disease. Repeat in 7 to 10 days for two to three applications.
16. Q. The foliage on my beans has angular, dead spots. Some of the spots have a yellow halo around them. The severely infected leaves are falling off the plants.
A. This is bacterial blight of beans. There are three bacteria that can cause it. All can be controlled with foliar sprays of a copper fungicide such as Kocide 101 or copper bourdeaux. This bacteria can also be seed transmitted.
17. Q. As they reach maturity, my bean pods are covered with brown rotten spots. Once the beans are picked, brought inside and placed in the crisper, these spots develop rapidly into a white fungus.
A. This is Anthracnose of beans. It is caused by a fungus. Apply fungicide on a regular schedule. Under severe conditions this disease can affect the leaves, stems and pods of the plant causing severe defoliation, loss of leaves and in some cases death. When picking beans to be placed in a crisper and used later, examine them closely, and if any pods are affected by this disease, discard them.
18. Q. I have noticed toward early summer the leaves of my green beans develop a rusting or browning appearance. What could be causing this problem?
A. Chances are your beans are infested with spider mites. Spider mites are one of the most destructive pests of garden vegetables, especially green beans, tomatoes and eggplant. These minute mites can destroy a planting of beans. Applications of approved miticides should begin as soon as the mites are noticed. Use of sulphur or Kelthane, begun early in the season, will usually result in satisfactory control. Use a teaspoon of a liquid detergent per gallon of spray mixed, direct sprays to the undersides of leaves and apply every 5 days for four consecutive sprays.
19. Q. My beans come up every year looking as if they are damaged. The leaves are curled and snarled. What is my problem?
A. The apexes or shoots of the leaves were damaged when they were very small by a tiny insect called a thrip. The thrip rasps the tissue of the leaf's growing point causing it to "bleed" or secrete plant juices. The thrip then feeds on these juices. Most plants recover from this damage. Control thrips with diazinon or malathion at 7- to 10-day intervals. Begin spraying when plants first emerge since most damage occurs then. Use as directed on the label.
20. Q. I have little black weevils chewing up my dry beans and peas. How did they get into the jars? How do I prevent this problem?
A. These little black weevils are cowpea curculios. Adults laid eggs in the beans and peas while they were growing in the garden. The new adults are now emerging from the beans. They have been in the beans all the time.
To prevent this problem, temperature treat dry beans before storing. Two methods can be used:
1. Place in freezer for 48 hours.
2. Place in oven at 120 degrees F. for 30 minutes.
After treatment, bring to room temperature and seal in jars or other containers.
21. Q. I have small black insects with shiny wings all over the underside of my bean leaves. Will they hurt my plants? If so, how do I get rid of them?
A. These small black insects are aphids. Heavy infestations stunt plants, cause deformed growth and reduce yield. Control these pests by applying a labeled insecticide.
22: I would like to grow mexican jumping beans. I need to know what they really are and how to grow them.
A: The Mexican jumping bean gets its name because it jumps and rolls from side to side. Its movement is caused by the full-grown larva of a certain moth named Laspeyresia saltitans, which lives inside the bean. When the larva moves, the bean "jumps". Jumping beans belong to the spurge family Euphorbiaceae and grow in Central and South America. They appear somewhat three-cornered in shape. Americans call the Mexican jumping beans, and people in the Southwest sometimes call them bronco beans because of the way they jump. They would be frost susceptible so you would plant and grow them in the spring after the danger of the last frost is past when edible beans are planted. As to where to get seed, buy the jumping beans from your regular source and plant the ones that DO NOT jump. The non-jumpers are probably viable since the insect larvae has not set up headquarters in them.
23. Q: My pole beans have produced. Now they seem to be forming another set of flowers. Will these flowers produce beans? Is it normal for Scarlet Runners to produce 2 distinct crops?
A: Yes, pole beans are usually continuous blooming and fruiting unless hot, summer weather causes blooms to drop. If you can keep the vines mite free, the blooms will begin to set again during fall and provide a bountiful fall harvest.
24. Q: I am trying to find out if this plant is poisonous to cows. It is a vine covering a fence with a light purple flower like a sweet pea, sweet smell.
A: There are few plants which cows will eat which are poisonous to themselves. The jack bean is a legume and should be treasured by the cow's taste buds. Even folks can eat the bean when they are small, immature and tender.
| Vegetable Page | Parson's Archive Home | Aggie Horticulture |