Cochise County is a wonderful place to garden. Almost any type of vegetable or fruit can be grown successfully provided one chooses appropriate varieties and plants at the right time.
Vegetables
Question:
Are there any garden vegetables that can be planted for a fall harvest in Cochise County?
Answer
Yes! Many of the cool season crops, those that can withstand freezing temperatures, do very well in Cochise County in the fall. In fact, the fall in Cochise County is better generally than the spring to raise cool season crops. These vegetables include the [brassica] family - broccoli, cauliflower, kale and cabbage among others. Also, spinach, beets, peas, radishes, lettuces, mustard greens, and other greens may be planted. The onion family, which includes garlic, does well when planted in the fall and then over-wintered and harvested in early spring.
Question:
I have several cucumber, pumpkin, and squash plants that have discolored leaves and distorted leaves. I see no insect damage and have sprayed for powdery mildew. The plants have adequate nutrition and are watered regularly. What's wrong with my plants?
Answer
Your curcurbits, (squash and melon family), have been infected with a virus. There are several different viruses that infect this family of plants. They include: cucumber mosaic virus (CVM), squash leaf curl virus (SLCV), squash mosaic virus (SQMV), watermelon mosaic virus (WMV) and zucchini yellow mosaic virus (ZYMV). Each of these pathogens usually have several strains. Sometimes an infected plant may have more than one virus causing the symptoms. Therefore, it makes an exact diagnosis difficult with out laboratory work.
Plants will have mottled leaves, that is patches of green and yellow, often in varying hues mixed in the leaf. Whole plants and leaves are usually smaller than normal and many times deformed and fragmented. Cucumber, melon and squash fruit are also small, stunted and colored unusually. The fruits at times will have warts and be bumpy.
Viruses can not survive outside of living organisms. They may be contained in the seed when planted, which occurs with SQMV. Insects serve as vectors, (transmittance agents), for many viruses. Sucking insects like aphids and white flies and chewing insects such as cucumber beetles and grasshoppers transmit virus particles from infected plants to healthy ones.
Control
Some virus resistant varieties are available; their use is advisable. Control of host plants like weeds serve as stores of viruses as well as infected crop plants. Destroy these plants as soon as symptoms appear. Control insects which transmit viruses from one plant to another. I know of no chemical or natural cures for viruses in plants. The plant many times will live in a weakened state much like what happens to humans when we get a viral flu or cold.
Question:
I have strawberry, raspberry and grapes that were growing well but now have leaves that are drying up around the edges and in the middle of the leaves. I water every day for five to ten minutes with overhead sprinklers that are on a timer clock. Do these plants have a disease?
Answer
Your plants are not getting enough water for two reasons. The first is that water volume and watering duration are not adequate. The second is that as you water salts in the water are added to the soil in addition to natural salts that are native to our desert soils. These salts, in part, are sodium, carbonates, calcium, chlorine and perhaps some heavy metals. To correct the problem start watering every other day for a half hour then check the water penetration depth using a soil probe or long screwdriver. If they go in an inch or two in the ground then you need to water. If it goes in a foot or two don't water. Once a month or so a deep watering is needed to leach out salts causing them to past the root zone. The drying of the leaf edges is cause by the plant taking up salts through the root system which are then conducted up to the leaves. The leaf cells pump" out water into the "saltier" intercellular spaces so that equilibrium is reached between salts within and without of the cell. This removal of water from leaf cells causes the drying that you see."
Question:
Why don't I have any summer squash being produced? There were some fruits early on in the season but now there is just vines and flowers growing. Also my tomatoes are not producing and some that have had fruit are cracked. What can I do?
Answer
With hot weather pollen of some plants becomes less viable and does not pollinate therefore fruit do not form. When the hot weather stops then fruit will set. This is also true for tomatoes, bell peppers, chili peppers and some members of the squash family. Tomatoes will crack from hot weather also and irregular watering. The biggest factor causing tomatoes to crack is the variety genetics. If a variety description list the tomato as crack resistant it will probably not crack. A crack resist tomato variety is Mountain Pride"."
Question:
My tomatoes have small water-soaked areas that at first appear to be bruises, then turns into brown sunken leathery areas always at on the blossom end of the fruit. Some of the sunken areas turn black. These diseased fruits usually ripen before the non-infected fruit. What disease do my tomatoes have?
Answer
This disease, call blossom-end rot, is caused by a localized deficiency of calcium in the fruits. Calcium is required in large quantities by growing cells like those in the blossom-end. When this rapidly growing tissue is deprived of the calcium needed for growth, especially cell-wall construction, tissues break down resulting in blackened, dry sunken spots or areas on at the blossom-end of the fruit. Water stress usually creates this disorder because inconsistent watering will not allow the plant to translocate sufficient calcium. Also high levels of nitrogen can cause vigorous growth early in the season which with water stress can compound the problem. Blossom-end rot is also seen in chili and bell peppers and members of the squash and melon family.
Control
It is important to regulate soil moisture and maintain that moisture at a relatively constant level where possible. Plenty of organic matter in the soil and mulching plants will help maintain consistent soil moisture. Also avoid high applications of nitrogen to the plants. Some varieties of tomatoes are less susceptible to blossom-end rot. These include Early Girl, Floradel, Floradade, Tropic and Jet Star. It has been demonstrated that foliar sprays of calcium chloride, (1 lb./25 gallons of water), or calcium nitrate, (2 lbs./25 gallons of water), can help reduce this problem. Applications must be made before calcium levels fall below critical levels and must be applied weekly for 3 to 4 weeks.
Source
Vegetable Diseases and Their Control. A. F. Sherf and A. A. MacNab. 1986. pp. 689-691. John Wiley and Sons, New York.
Question:
My tomatoes have cracks around the stem end and black sunken tissue on the blossom end. What is wrong?
Answer
Cracking around the stem is caused by high temperatures and watering practices. However, the cracking is genetic in that there are varieties that do not crack. The Mountain" series, including "Mountain Pride" and "Mountain Delight", from North Carolina do not crack. The other problem is called blossom end rot. It is a physiological condition that arises because of varying moisture in the soil. The plant cannot transport enough calcium to meet the demand in forming cell walls even though there is plenty in the soil. Most nutrients are carried in water to uptake sites on the root hairs. Sometimes a secondary fungus like sooty mold will colonize the tissue, causing a black fungal growth. Other plants like squash, pepper, chile and melons also can have blossom end rot."
Control
Water consistently and deeper and apply mulch to keep soil moisture consistent. Early fruit have more blossom end rot problems that fruit produced later, so be patient. The fruit is still edible just cut out the bad parts.
Question:
Why are the melons and winter squash that I planted in May looking so poor? Some of the skin of the fruits are soft and yellowish while others very brown and the skin is hard. What should I do to grow good melons and winter squash?
Answer
You have sunburned fruit. It is to late to apply sun-tanning lotion! I have found that it is best to plant melons, pumpkins, and winter squash after the first of July. The reason is that normally we will have some cloud cover and rain while the really hot weather of May and June is subsiding. Soil temperatures are warm enough so that seeds germinate rapidly. If you plant just after the last spring frost the plants will grow normally. However, the fruits will be produced to early and become sunburned because of the heat and poor leave cover, which shades the fruit, during the month of June when compared to plants sown in July. We have a long enough growing season to mature these crops in September and October. Our normal first fall frost in Cochise County is in late October. Try planting melons, pumpkins, and winter squash now and you will have better results, I guarantee!