admin

Sep 29 2004

October Landscape Activities

29 September 2004

Virginia Cooperative Extension, Charlottesville/Albemarle County Office
460 Stagecoach Road, Charlottesville, Virginia 22902
phone: 434.872.4580 fax: 434.872.4578

~~~~~~~~~~~~~

If your landscape survived the hurricane remnants of recent weeks and your lawn no longer resembles a rice patty you might be inspired to get out and do some fall cleanup, spring preparation, or maybe plant a tree. Here are some suggested activities and ideas for the next few weeks.

Old, fallen leaves contain the disease inoculum for plant infections next year. If you have disease-infected plants, prune out infected branches in the late fall and winter when the disease-causing organism is inactive. Remove any infected debris from around the plant's base and dispose of it.

Looking to put some outstanding fall color into your landscape? Check out Virginia sweetspire (Itea virginica 'Henry's Garnet'). It is a medium-sized shrub that spreads by rhizomes, ultimately forming a large stand if left unchecked, loaded with 2 to 6-inch-long racemes of fragrant, white, late-spring flowers lasting two to three weeks. Virginia sweetspire prefers a moist, fertile soil, but is adaptable to full sun or part shade and has no major disease or insect problems.

Start a family tradition by planting a tree or shrub in honor of a holiday, birthday, or anniversary. While celebrating the special occasion, you can also beautify your landscape and improve the air quality around your home.

When selecting trees for fall color keep in mind that color is more strongly influenced by genes in the plant than by the environment. Trees selected in the fall when they are in full color can be expected to produce the same colors in future years. Red Maple cultivars that display outstanding colors include 'Red Sunset,' 'October Glory,' and 'Autumn Flame.'

You probably can name some annual and perennial flowers that are attractive to hummingbirds. If you want to plant some common trees visited by hummingbirds consider this list: buckeyes and horse chestnut (Aesculus species), crabapple (Malus species), hawthorn (Crataegus species), silk tree (Albizia julibrissin), Siberian pea shrub (Caragana arborescens), and tulip poplar (Lirodendron tulipifera).

The top of shrub or tree roots should be flush with the ground, so the planting hole should be no deeper than the root ball.

To minimize the look of open spaces between new shrubs, plant a low-growing ground cover, such as bugleweed (Ajuga reptans) or winter creeper (Euonymus fortunei).

Your trees and shrubs have begun to harden for the upcoming cold weather. To encourage this, remove mulch from around the stems of shrubs and trees.

October and November are generally considered the best months to plant trees and shrubs. Garden centers and nurseries usually stock a good selection of woody plants at this time of year. Select some accent plants for your landscape that will provide autumn colors. Trees that turn red include dogwood, red maple, sweet gum, and red or scarlet oak. Shrubs with red fall foliage include viburnum, winged euonymus, and barberry.

While you can still identify them easily, prune dead and diseased branches from trees and shrubs.

Light pruning of both needle and broadleaf evergreens is recommended in late fall to encourage a strong framework to help the plant overcome any snow damage. Remove any weak or crowded branches.

In deciding on new trees or shrubs to plant around your home, remember to select varieties with a mature height to fit the desired location. This will greatly reduce pruning and other maintenance in the future.

Make a note of plants displaying outstanding fall colors as you drive along city streets and the surrounding countryside. You may wish to incorporate some of them into your own landscape.

Bagworm on an evergreen

If your climbing roses are in an exposed location, tie them up firmly with broad strips of rags so the wind will not whip them against the trellis and bruise the bark.

Use cold frames to over winter cuttings of trees and shrubs and perennial seedlings started in mid- to late summer. Bulbs prepared for forcing also can be stored in cold frames until time to take them indoors.

It is too late this year to prune roses because they would become subject to winter injury. However, the rose garden should be raked and cleaned to prevent black spot and other diseases. Additional mulch should be added after the ground has frozen.

Pick bagworms from evergreen shrubs. This will eliminate the spring hatch from overwintering eggs.

Do not become alarmed if your yews, pines, arborvitae, and junipers begin to shed their interior needles. It is natural for them to do so at this time of year.

White pines are shedding their older needles now. Rake them up and use as mulch on azalea, rhododendron, andromeda, and camellia.

~~~~~~~~~~~~~

For more information on gardening, contact your local Virginia Cooperative Extension office. Many county Extension offices have a help desk that is staffed by Master Gardener volunteers. These volunteers are trained to answer questions about garden and landscape topics. The local Virginia Cooperative Extension office numbers are Albemarle 984-0727, Fluvanna 591-1950, Greene 985-5236, Louisa 540-967-3422, and Nelson 263-4035.

Sep 21 2004

Invasive Tree: Ailanthus altissima

21 September 2004

Virginia Cooperative Extension, Charlottesville/Albemarle County Office
460 Stagecoach Road, Charlottesville, Virginia 22902
phone: 434.872.4580 fax: 434.872.4578

~~~~~~~~~~~~~

Ailanthus altissima leaves

Maybe you call it tree-of-heaven, tree-of-paradise, or stink-tree, but its scientific name is Ailanthus altissima. Those who regularly battle Ailanthus have been overheard using some other names as well. The Ailanthus problem is well known among natural resource managers who classify Ailanthus as an invasive exotic: invasive because the tree spreads rapidly and has few insect or disease pathogens and exotic because this species is not native to the U.S. Among invasive exotics, Ailanthus is especially notorious due to its ability to quickly invade disturbed areas and resist control efforts.

Introduced from Asia to the U.S. in 1784, Ailanthus was originally used as an urban landscape tree and later to stabilize construction sites. However, like many introduced species, Ailanthus quickly escaped from its intended uses and has since spread to every region of the U.S. Ailanthus is able to withstand pollution and stabilize erosion prone road cuts but that is where the benefits end. Ailanthus has invaded urban and rural forests alike, displacing thousands of acres of native vegetation and offering little or no economic or wildlife benefits in return. And, it is spreading.

Ailanthus can be easily confused with sumac (Rhus typhina) and young black walnut (Juglans nigra). Ailanthus leaves are pinnately compound (i.e., they have multiple leaflets on a single leafstalk). Leaves are typically 12 to 24 inches long and unlike walnut have an odd number of leaflets (between 11 and 25). One to four lobes distinguish the bottom of each leaflet with gland-dots at the tip of each lobe. Twigs and stems are light brown and covered with tan bumps or lenticels. The pith or inner core of the twig is a spongy brown color (compared to the dark brown chambered pith of walnut) and produces the odor from which Ailanthus earns the name stink-tree. Twigs and branches break easily which aids in identifying pith color and odor.

Ailanthus altissima seed pod

Like eastern redcedar (Juniperus virginiana) and Virginia pine (Pinus virginiana), Ailanthus is considered a pioneer species, a plant that is generally shade intolerant and grows rapidly on disturbed sites such as fallow agricultural lands, field and forest borders, recently harvested forest stands, road cuts, and right-of-ways. Ailanthus spreads prolifically from seeds, stumps, and roots. Mature female trees produce up to 300,000 windborne seeds each fall. Both male and female trees propagate quickly from root suckers and stump sprouts and can reach 9 to 12 feet in their first year of growth. Seedlings and sprouts rapidly form pure stands by outgrowing surrounding vegetation and by producing an allelopathic compound that suppresses many native woody and herbaceous species.

Current control methods for Ailanthus can be broadly characterized as physical and chemical and may be approached differently depending on the size of the Ailanthus population. Before control measures are undertaken it is crucial to consider how the reclaimed site will be used and that the desired tree species be established soon after Ailanthus is initially controlled. Landowners must always remain vigilant for reemerging populations of Ailanthus.

Physical control methods include cutting, removal of roots, burning, and mowing. Cutting alone will not kill Ailanthus. In fact, the tree will vigorously resprout from the roots and stumps and will result in many more stems than were initially cut. Digging roots is practical only for very small patches, as all traces of root must be removed. Similar to cutting, burning and mowing kill only the above ground stems, and trees will resprout from the roots. Because root removal is extremely labor intensive, and burning and mowing are non-selective, cutting is usually the preferred method of physical control. However, cutting is only effective when coupled with chemical control.

The best control will result from a late growing season combination of physical and chemical control that begins by cutting trees before they have produced and scattered their seed. For the homeowner with one or a few trees to control, the easiest method is to cut the tree down and apply full strength glyphosate to the top of the cut stump. Glyphosate is sold under the trade name Roundup and others now that the patent has expired. For the landowner with a larger area to manage, two types of herbicide, imazapyr and triclopyr have proven very effective in controlling Ailanthus. Imazapyr is sold under the trade names Arsenal (water-soluble salt) and Stalker (oil base) and triclopyr under the trade names Garlon 3A (water-soluble salt) and Garlon 4 (oil base). Both water and oil based mixtures have benefits and drawbacks. In general, water-soluble mixtures are easier to mix and clean, and break down more quickly in the environment. On the other hand, while more difficult to clean up and longer lasting in the environment, oil mixtures are usually more effective in penetrating bark and leaves.

To be safe and effective, herbicide use requires careful knowledge of the chemicals, appropriate concentrations, and the effective method and timing of their application. For more details, read the herbicide label.

Despite effective cutting, burning, and use of herbicides, Ailanthus can quickly reestablish itself by airborne seed from neighboring properties. You might share this information with your neighbors and encourage them to eradicate their Ailanthus populations as well. You might also consider sharing the costs of equipment, herbicides, and application with your neighbors.

~~~~~~~~~~~~~

Sep 01 2004

Cultural Pest Management

1 September 2004

Virginia Cooperative Extension, Charlottesville/Albemarle County Office
460 Stagecoach Road, Charlottesville, Virginia 22902
phone: 434.872.4580 fax: 434.872.4578

~~~~~~~~~~~~~

Managing pests in the landscape can be done in many ways. Often there is no one way that is effective alone. By integrating multiple methods of pest management we are often able to reach a satisfactory situation. The goal is to reduce pest populations to a low enough number so the threat of damage is minimal. Eradication of a pest is rarely practical when it comes to our common, well-established problems. In these cases it is actually a good idea to leave a few of the bad guys out there to provide food for their natural enemies.

One of the keystones to managing pests of all kinds is called cultural pest management. The idea here is to manipulate the environment to reduce the likelihood of pest problems. By making an area less attractive or unsuitable for a pest, there is a very good chance the pests will be less likely to survive in that environment or they will find somewhere else to go. Because these sorts of tactics are proactive instead of reactive we can also call this preventive pest management.

Cultural pest management methods include a broad range of practices that can be modified or manipulated to manage one or more pest problems. Cultural techniques may include crop rotation, tillage, timing of planting and harvesting, cover crops, choice of plant cultivar, competition, fertilizer or irrigation practices, and sanitation. Cultural methods are more effective when used in conjunction with other pest management strategies (e.g. mechanical, biological, and chemical control methods).

Weed control approaches often include hoeing (mechanical) and herbicides (chemical). However, cultural weed control methods could also include tillage, mulching, reducing inputs of irrigation and fertilizer, reducing weed seed sources, and using more desirable plants that compete with weeds. Reducing weed seed sources can be done by hoeing or pulling annual weeds before they go to seed and limiting the introduction of outside sources which may include maintaining borders, not importing weed-contaminated soil, and only using well-composted manures. Weeds tend to grow where bare soil and water are available. In these circumstances, you can use mulch or consider planting wildflowers and/or native grasses to reduce the area available to weeds.

Plant diseases are often difficult to control once they appear. Cultural practices can be used effectively to prevent some plant diseases from getting started. Disease resistant plant varieties and rootstocks are available in many cases. In vegetable and fruit gardens and annual flower beds, crop rotation and sanitation are easy and effective. This means you should not plant the same species or same family of plants in the same bed in successive years and you should remove diseased plants as soon as symptoms appear. Never compost diseased plant material and remember to clean up your garden at the end of the season so diseases and insects do not overwinter in the refuse.

Many insects can also be controlled using cultural methods. For instance, some insect populations lay their eggs in the soil near where they were feeding this year so their offspring will be able to find food easily next year. If you moved your beds or rotated your crops those young insects will go hungry and their population will be reduced. Aphids can be reduced by not applying excessive amounts of nitrogen fertilizer which can create very succulent foliage that attracts aphids. Spider mites, thrips, and other pest populations can be reduced by knocking them off plants with a spray of water from your hose so they can be gobbled up by predators such as ground beetles. Reducing nearby weeds where many insects find shelter and alternative food sources during the growing season and over the winter will help as well. Other options include tillage to expose soil insects to predators and the elements and trapping.

Insects stuck to a sticky trap

There are traps available that can reduce populations somewhat but mostly traps provide good information on what insects are present during which part of the growing season so you know when to take action. One of these devices is called a sticky trap and consists of a plastic card colored to attract certain insects and covered with a sticky substance to catch the insects.

Knowing your ecosystem, that is the plants in your landscape and the potential problems and good bugs you might find, will help you make quick and educated decisions when a problem does occur. It is a lot of information to keep up with but if you take in a little bit at a time while you are out in your landscape each week it is not so overwhelming.

~~~~~~~~~~~~~

For more information about landscape topics contact your local Virginia Cooperative Extension office. Many county Extension offices have a help desk that is staffed by Master Gardener volunteers. These volunteers are trained to answer questions about home and landscape pest problems. The local Virginia Cooperative Extension office numbers are Albemarle 984-0727, Fluvanna 591-1950, Greene 985-5236, Louisa 540-967-3422, and Nelson 263-4035.

Aug 26 2004

Vegetable Harvest

26 August 2004

Virginia Cooperative Extension, Charlottesville/Albemarle County Office
460 Stagecoach Road, Charlottesville, Virginia 22902
phone: 434.872.4580 fax: 434.872.4578

~~~~~~~~~~~~~

Master Gardeners taking in vegetable entries at the county fair. Pictured are Ann Foster, Al Minutolo, and Bob Hammond.

The most anticipated moment for summer gardeners is harvesting. This might be even more significant for you if you are planning to enter some of your produce in the county fair. What a great way to showcase your green thumb and join in the fun at the fair.

Most gardeners in their eager anticipation harvest too early (or sometimes too late). With tomatoes, it may be easy to tell when fruit is ripe, but for a beginning gardener, telling when to harvest other vegetables may be difficult. Sometimes as much produce is lost due to improper harvesting as due to insects. The goal should be to harvest vegetables when quality is highest. After all, it is the quality of garden produce that sets it apart from store bought produce.

Here are descriptions of harvesting techniques for some common home grown vegetables.

Green or Wax Snap Beans--Pods should break off easily with a "snap" when ready for harvesting. The seeds should not cause the pods to bulge.

Pole and Half Runner Beans--Harvest as snap beans when young and stringless or shell beans when mature.

Lima Beans--Pods should be green with swellings to show the beans inside. Open a pod or two; beans should be plump but still green or gray-green (not white). Pick often to prolong picking season.

Sweet Corn--Harvest while the husk is still dark green. Kernels should be full size and yellow or white to the tip of the ear, but still in the soft, "milk stage" of growth. Corn is sweetest just as the silk blackens. Remember that corn matures very rapidly in hot weather and that it should be refrigerated immediately after picking to prevent the sugar from turning to starch.

Cucumbers--Those of moderate size are best. Yellowing indicates old age. Do not allow old cucumbers to remain on the vine because they will keep the vine from bearing more cucumbers. Harvest while young and green when the seeds are soft. To use cucumbers for sweet pickles, harvest when two to three inches long; for dills, five to six inches; and for slicing, six to eight inches.

Muskmelons--They develop the best flavor when they ripen in warm, dry weather. They may taste more like cucumbers if they mature in cool, rainy weather. Pick them at "full slip" stage when the stem separates readily from the fruit. Fully ripe melons are sweetest. As the melon ripens, the netting becomes more prominent and the background color changes from a light green to a tan or yellow cast. After harvesting, the fruit can be held at room temperature for one to three days until the blossom end softens.

Okra--The best quality is when the pods are two to three inches long. They may have to be harvested daily to get the quality size. Pick within a few days after the flower petals have fallen whether pods are to be used or not. If pods are allowed to ripen, the plant ceases to produce.

Eggplant--Harvest when the fruits are large and shiny with an even deep purple color. Keep mature fruits picked off and plants will produce over a long period of time. Fruit in which the seeds have turned brown are of poor quality and past the edible stage. To tell if the fruit is mature, press the side of the fruit slightly. If the indentation remains, it is mature.

Potatoes--Dig them whenever tubers are large enough to eat. Dig only what will be used immediately, because they keep better in the soil than in a warm house or basement. Harvest when the tops have died down but before the first heavy freeze. When digging, avoid skinning and injury. Avoid long exposure of potatoes to light.

Tomatoes--Harvest them when fully vine-ripened and dark red. Regardless of the state of maturity, picked tomatoes should be put in the shade, not the sun. Light is not necessary for immature tomatoes to ripen. Sun causes uneven ripening and abnormal color formation. To obtain good color and flavor, hold partly ripe fruit at 70 degrees F then place in the refrigerator. Pick some green tomatoes and store in a cool (about 55 degrees F), moist, dark place before the first killing frost. Ripen by putting them in a location that is 70 degrees F.

Cabbage--Harvest anytime after a firm head develops. If some plants cannot be harvested after they reach full maturity, bend them to the ground on one side and break part of the roots to reduce the possibility of head splitting from excess water intake. If heads have not split, they can be stored for long periods at temperatures of 32 to 45 degrees F.

Broccoli--Cut while clustered flower heads are firm and green. Take heads with leaves and 5 or 6 inches of stem (also edible). Do not damage short side branches. They will produce smaller heads if left to grow.

Brussels sprouts--Twist or snap off sprouts when they are firm and still deep green (usually about the time lowest big leaves start to yellow). Harvest lowest sprouts first. Upper ones will continue to enlarge to harvesting size. The flavor of Brussels sprouts improves after exposure to frosts.

Cauliflower--As soon as blossom heads (farmers call them curds) begin to form, pull the upper outer leaves over them to shade from the sun. This blanching process gives a white curd. Inspect from time to time and cut off curd when the flower sections begin to separate.

Kale--Cut off outer leaves from plants as needed. In thinning, pull smaller plants and use (but do not eat roots).

New Zealand Spinach--Pinch off or cut with a sharp knife 2 to 3 inch lengths of tender stem tips with leaves. New shoots will grow to replace them.

Turnips and rutabagas--Pull young plants with tiny roots to thin rows and give growing room to the remaining plants. Eat thinnings, tops and all. At 2-inch diameters, roots are tastiest, and tops are still good as greens. At 3 inches and above, roots are still good and store a little better. Late planted rutabagas can stay in the ground until needed.

~~~~~~~~~~~~~

For more information on gardening, contact your local Virginia Cooperative Extension office. The local Virginia Cooperative Extension office numbers are Albemarle 984-0727, Fluvanna 591-1950, Greene 985-5236, Louisa 540-967-3422, and Nelson 263-4035.

Jul 21 2004

Fall Vegetable Gardening

21 July 2004

Virginia Cooperative Extension, Charlottesville/Albemarle County Office
460 Stagecoach Road, Charlottesville, Virginia 22902
phone: 434.872.4580 fax: 434.872.4578

~~~~~~~~~~~~~

By planning and planting a fall vegetable garden it is possible to have fresh vegetables up to and even past the first frosts. At the time of year when retail vegetable prices are on the rise, you can be reaping large and varied harvests from your still-productive garden site.

Many varieties of vegetables can be planted in mid- to late summer for fall harvests. Succession plantings of warm season crops (such as corn and beans) can be harvested up until the first killing frost. Cool season crops (such as kale, turnips, mustard, broccoli, cabbage) grow well during the cool fall days and can withstand light frosts. Timely planting is the key to a successful fall garden.

To determine the time to plant a particular vegetable for the latest harvest in your area, you need to know the average date of the first killing frost and the number of days to maturity for the variety you are growing. Choose earliest maturing varieties for late plantings. The formula below for determining the number of days to count back from the first frost will help determine when to start your fall garden.

Number of days from seeding or transplanting outdoors to harvest
+ Number of days from seed to transplant if you start your own seed
+ Average harvest period
+ Fall Factor (about two weeks)
+ Frost Tender Factor (if applicable) (two weeks)

= Days to count back from first frost date

The Frost Tender Factor is added only for those crops that are sensitive to frost (corn, beans, cucumbers, tomatoes, squash), as these must mature two weeks before frost in order to produce a reasonable harvest. The Fall Factor takes into account the slow growth that results from cool weather and short days in the fall, and amounts to about two weeks. This time can be reduced from 2-5 days by pre-sprouting seeds. Almost any crop that is not grown from transplants can benefit from pre-sprouting. Sprout seeds in doors, allowing them to reach a maximum length of one inch. Sprouted seeds may be planted deeper than normal to help prevent drying out, and they should be watered well until they break the soil surface. Care should be taken not to break off the sprouts when planting them.

Before you plant fall crops prepare the soil by restoring the nutrients that were removed by spring and summer crops. A light layer of compost, aged manure, or a small application of complete chemical fertilizer will boost soil nutrients in preparation for another crop. Dry soil can make working the soil difficult and inhibit seed germination during the mid-summer period. Plant fall vegetables when the soil is moist after a rain, or water the area thoroughly the day before planting. Seeds may be planted in a shallow trench to conserve moisture. Cover the seeds about twice as deeply as you do in the spring. An old-time trick for germinating seeds in mid-summer is to plant the seeds, water them in well, and then place a board over the row until the sprouts just reach the soil surface; at that time remove the board. Plastic, especially black plastic, may cause the soil to get too hot. In severe hot weather a light, open type of mulch, such as loose straw or pine boughs, may be placed over the seeded row. This must be removed as soon as the seedlings are up so that the seedlings receive full sun. Starting transplants in a shaded cold frame or in a cool indoor area is another possibility. A thin layer of organic mulch helps retain soil moisture and keeps the soil warm without deterring germination.

Once young plants are established, a heavier layer of mulch can be used to hold moisture and control weeds. Irrigate when necessary so the young plants have sufficient moisture. Fall plantings often have fewer insect problems, as they avoid the peak insect activity period of midsummer. However, some insects, such as cabbageworm and corn earworm, may be even worse late in the year than in summer. Avoid some pests and diseases by planting crops of different families than were originally in that section of the garden.

Some of the best quality vegetables are produced during the warm days and cool nights of the fall season. These environmental conditions add sugar to sweet corn and crispness to carrots. Parsnips and Jerusalem artichokes are examples of crops that are distinctly improved by a touch of frost.

The fall garden gives you a chance to try again any crops that failed in the spring. Some crops, in fact, grow well only in the fall in certain areas. Cauliflower and long-season Chinese cabbage are two examples of crops which do not produce well in Virginia's mountain areas in spring because they cannot reach maturity before the cool weather ends.

Protection of vegetable plants during cold periods can extend your season even further. Though in the hot days of summer the last thing you want to think about is planting more crops, look ahead to the fall garden, which offers its own satisfaction through its prolonged harvest of fresh vegetables, savings in food costs, and the knowledge that you are making full use of your gardening space and season.

~~~~~~~~~~~~~

This fall Virginia Cooperative Extension will be offering Master Gardener training in Greene & Nelson Counties. For more information, call (434) 984-0727 or your local Virginia Cooperative Extension office.