Keeping the roses smelling like a rose

Prevent Rose Diseases

                 Spectacular blooms and diverse types and varieties make roses a favorite of many Kentucky gardeners.  However, our warm, humid growing conditions create an ideal environment for serious problems each year with black spot and powdery mildew.

                Gardeners can nip these fungal diseases in the bud by planting resistant or tolerant varieties and creating an unfavorable environment for disease development. It may be necessary to use fungicides throughout the summer, especially on susceptible varieties.

                The Hardin County Cooperative Extension Service has materials on resistant and tolerant varieties.  Nursery catalogues also publish this information.

                To reduce foliar diseases, try to avoid conditions where rose leaves remain wet for an extended period of time. Do not wet foliage when watering plants and allow sufficient time for leaves to dry before nighttime.  Prune out shading vegetation from overhanging trees and provide space between rose bushes to improve ventilation and sunlight penetration.

                Sanitation also is important for managing rose diseases. If you have not already removed and destroyed old leaves, winter-damaged canes and debris, do it as soon as possible. These items are a source of disease-causing organisms.

                Many fungicides are labeled to control rose diseases. Always check the label to be sure the product controls black spot and powdery mildew and read and follow application instructions.  To maintain disease suppression, repeat fungicide applications at 10 to 14-day intervals throughout the growing season.

                Black spot produces dark, circular spots with fringed borders on the top or bottom side of leaves. Infected leaves often turn yellow and drop, reducing flower numbers and quality.

                White, powdery fungal growth is a sign of powdery mildew. It is easy to locate on such plant surfaces as leaves, stems and flower buds.  Infected leaves may be small and deformed.

                Two other important, but less common, foliar diseases of roses are downy mildew and rust.  Downy mildew produces lesions that are an off-color, later turning purplish brown.  It leads to defoliation.  Rust-colored spots on leaves and stems indicate the disease, rust. Severely infected leaves may shrivel and turn brown.

Rose Rosette

                Another summertime disease is rose rosette, which affects roses throughout Kentucky.  It is not a fungal disease.

                This disease is spread by a microscopic mite.  The primary host is multi-flora rose, a thorny plant native to the Orient and introduced into the United States as a conservation plant and “living fence.”  The disease also affects cultivated roses.

                Early symptoms are increased growth of shoots, which appear more succulent than normal and develop excessive thorns, and distorted, dwarfed leaves. The affected shoots are not winter hardy and produce few blooms. Rose plants eventually die.

                Early disease detection is essential to keep rose rosette from spreading. Remove and destroy any infected roses to keep the disease from healthy plants that are nearby.  Carefully remove diseased plants to avoid scattering disease-carrying mites to other plants.  Since multi-flora roses might be a disease reservoir, remove and destroy any located within one-eighth of a mile from the rose bed.

                For more information on growing roses, contact the Hardin County Cooperative Extension Service at 270.765.4121, email:  Amy.Aldenderfer@uky.edu by webpage: www.hardinext.org and on Facebook.

Educational programs of the Kentucky Cooperative Extension Service serve all people regardless of race, color, age, sex, religion, disability or national origin.

Rain and Mosquitoes

                The combination of plentiful rain and warmer weather mark the beginning of mosquito season.  To get a head start on mosquito control around your home, farm and business, eliminate potential breeding sites that provide the quiet, non-flowing water these bothersome pests need to develop.

                You can decrease mosquito populations by depriving them of places to breed.    However, eliminating these sites often is easier said than done, because these locations aren’t always obvious.  A neglected bird bath, clogged rain gutter or boat bottom allowed to accumulate water can produce hundreds of new mosquitoes daily.  Did you know that immature mosquitoes, also known as “wigglers,” can develop into biting adults in as little as one week?

                Following the steps below will keep your property from becoming a prime mosquito breeding ground:

                Since used tires are a primary mosquito breeding area, remove all discarded tires.

                Also, dispose of outdoor, water-holding containers such as empty tin cans, plastic containers, ceramic pots, plastic sheeting and the like.  Don’t let water accumulate in flower pot drainage saucers and pet dishes more than two days.

                Turn over wading pools and wheelbarrows when not using them.

                Change water in birdbaths and wading pools at least once a week.

                Check around faucets, air conditioner units and condensation drains, cisterns, cesspools and septic tanks for water puddles that remain for several days.  Eliminate these puddles and repair any leaks to prevent future water accumulations. 

                Consider stocking ornamental pools with mosquito fish.  You can buy these predacious minnows, or seine them from creeks or streams.

                Many small fish will feed on mosquito larvae in ditches, ponds and similar locations.  To enable fish to get to immature mosquitoes, control emerging vegetation and keep banks steep rather than having a gradual drop off.

                Standing water in roof gutters can produce millions of mosquitoes each season; so clean clogged gutters in the spring and fall, and periodically inspect gutters to be sure they properly drain.

                Remove standing water from patios, decks or flat roofs.

                Clean and disinfect swimming pools, outdoor saunas and hot tubs.

                Landscape gardens and lawns to prevent water accumulation.  Irrigate them sufficiently for good growth, but not to the point that water stands for several days.  If you have installed a rain garden, make sure that the water drains out in two days.

                To prevent water accumulation in tree holes or stumps remove,  or drain them.

                Tremendous numbers of mosquitoes can breed in shallow, marshy or swampy locations, ditches, and other low areas.  On farms, these pests can develop in standing water in hoof prints around watering troughs, seepage areas and similar locations. Draining or filling up these areas is an effective long-term solution.  If it’s not possible to eliminate standing water in all these situations, consider using a mosquito-specific larvicide (insecticide to control immature mosquitoes).

                Larvicides contain the active ingredient Methoprene (an insect growth regulator) or the bacterial toxin produced by Bacillus thuringiensis israeliensis.  These products are essentially harmless to fish, wildlife and other non-target organisms.  The easy-to-apply products come in water-soluble granules, pellets or briquettes, and usually are available from farm supply stores, and pesticide dealers, or the Internet.

                Gimmicks advertised in print and electronic media generally are ineffective.  These include ultrasonic devices, mosquito-repelling plants and candles or garlic.  Traps that capture large numbers of mosquitoes haven’t been proven effective at eliminating pest bites, even though they might capture impressive numbers of mosquitoes.

                A community-wide effort might be necessary to eliminate standing water such as swamps, marshes and ditches in public areas.

                For more information, contact your Hardin County Cooperative Extension Service at 270.765.4121, www.hardinext.org or Amy.Aldenderfer@uky.edu.

Educational programs of the Kentucky Cooperative Extension Service serve all people regardless of race, color, age, sex, religion, disability or national origin.

Don’t Forget about the Lincoln Trail Area Master Gardeners’ 13^th Annual Plant Fair: MAY 21^st from 9 a.m. – 3 p.m. at the Hardin County Extension Office, 201 Peterson Drive, Elizabethtown. Rain or Shine! (hopefully, shine.)

Those Pesky Caterpillars!

TENT CATERPILLAR HATCHING NOW

    Eastern tent caterpillar egg hatch has started in Kentucky!

     Questions about how soon egg hatch will be completed and when tent caterpillars will begin to feed will soon be answered by Kentucky's spring weather.

     "When temperatures are in the upper 70s most of the eggs hatch in eight to ten days, however, highs in the 50s can spread hatch out over a month," said Lee Townsend, Extension entomologist in the University of Kentucky, College of Agriculture. "These caterpillars are basically inactive below 50 degrees so it's easy to see how great an effect temperature has on them."

     The tent caterpillar, which gets its name from the silken tent it constructs in tree branches, prefers wild cherry but also feeds on peach, apple, crabapple and other trees.

     This insect, which is common throughout the eastern United States, is a nuisance but poses no

health threat to humans.

     Because the eastern tent caterpillar has been identified as one of the risk factors associated with Mare Reproductive Loss Syndrome, UK scientists are intensely monitoring its activity.  As part of a comprehensive UK program this spring scientists also are watching other factors, including pasture

conditions and weather patterns.

          A patient approach will allow any early natural control, such as heavy rains or freezes, to have an effect, and we need to keep in mind that treating too early can mean that additional applications may be needed.  Spraying will be most effective when the nests are established and the caterpillars are actively feeding.  Waiting until the nests are about the size of a baseball or softball should be about ideal.

Natural enemies play an important role in reducing eastern tent caterpillar numbers in most years. Caterpillars are frequently parasitized by various tiny braconid, ichneumonid, and chalcid wasps. Several predators and a few diseases also help to regulate their populations. This, in part, accounts for the fluctuating population levels from year to year.

Prevention and early control is important. Removal and destruction of the egg masses from ornamentals and fruit trees during winter greatly reduces the problem next spring. In the early spring, small tents can be removed and destroyed by hand. Larger tents may be pruned out and destroyed or removed by winding the nest upon the end of a stick. Burning the tents out with a torch is not recommended since this can easily damage the tree.

Young caterpillars can be killed by applying an insecticide containing Bacillus thuringiensis var kurstaki. Larvae within the tents are protected beneath the webbing and are more difficult to kill with an insecticide.

Hardin County Extension Office (765-4121) www.hardinext.org is an excellent source of information on insect pest management, as well as the UK entomology department's web site at www.uky.edu/Agriculture/Entomology/enthp.htm.

Gardeners’ Tool Box Series:

Spring Flower Arranging - May 3, 2011

Back by popular demand!  Assemble a  small springtime flower arrangement.  The perfect gift for Mothers’ Day or give the class as a gift.  All the supplies for the arrangement will be included in the class fee. Registration ($10) and payment must be received by April 22. Class is held at the Hardin County Extension Office beginning at 6:30 p.m. 

Don’t Forget about the Lincoln Trail Area Master Gardeners’ 13^th Annual Plant Fair: MAY 21^st from 9 a.m. – 3 p.m. at the Hardin County Extension Office, 201 Peterson Drive, Elizabethtown.

Pest Management Tips for Home Vegetable Gardens

Now is a good time to start thinking about pest control for your home vegetable garden.

You can control pest problems, and perhaps prevent future difficulties, in your garden by doing some advance planning and following a few simple Integrated Pest Management practices. IPM promotes minimal pesticide use and emphasizes use of all available pest control methods including cultural, mechanical and biological practices to prevent pest problems.

Examples of the IPM approach include using plants with natural disease tolerance or resistance, using mulch to control weeds or row covers to prevent insect damage and using naturally occurring organisms such as lady beetles or praying mantis. 

Sanitation is another good IPM practice. Keep your garden well-groomed during active growth. Once you spot diseased plant material, remove it immediately to keep diseases from spreading. Also, promptly remove vegetable plants when they cease to be productive. Although you should clear out unproductive vegetable plants from the garden area, you can add this plant material to a compost pile.

Before you buy seeds, plants or fertilizer, start your garden off right by answering these questions.

Have you taken a soil sample to determine if soil fertility and acidity/alkalinity will meet plants’ nutrient requirements?

Soil test results will let you know how much fertilizer is required to provide plants with needed nutrients, while preventing excessive use that contributes to groundwater, stream and lake pollution. Plants that are stressed or weak from insufficient nutrients or a pH that’s too low or too high are more susceptible to disease and can’t readily tolerate insect damage. To give your plants a healthy start, soil test and apply the fertilizer and other amendments according to the recommendations.

Do you plant your garden crops in the same spot year after year?

Crop rotation can help prevent insect and disease build-ups. For example, potatoes, eggplant, tomatoes and peppers are subject to the same insect and disease problems. Therefore, none of these crops should be planted in the same location more than every three consecutive years. After three years, switch to a different crop like beans or corn. If you have limited garden space, plant some vegetable plants in containers such as large pots or half whisky barrels as a form of crop rotation.

Make a diagram of your garden each year to avoid planting the same or closely related crops in exactly the same spot too frequently.

How do you select a vegetable plant variety?

Whether you are planting corn or tomatoes, check to see that the variety you are planting has some disease resistance or tolerance. For example, select tomato varieties labeled “VFN,” as they’re resistant to Verticillium Wilt, Fusarium and root-knot nematodes. Whereas, a tomato variety leveled “V” is only resistant to Verticillium Wilt.

Do you buy the cheapest transplants?

When it comes to transplants, the best buys are the healthy ones. A healthy transplant was seeded at the right time, grown at the proper temperature and received adequate light and moisture. It will have a compact growth structure with very small distances between leaves. The leaves will be dark green, large and upright with no tendency to droop. Stems will be pencil thick and rigid.

Avoid transplants that are beginning to produce flowers or fruit. It might seem that buying a plant with blooms or fruit will give you a head start in the garden. However, plants trying to produce fruit or flowers are slow to develop the good root systems needed to support later fruit production.  Never buy plants that have insects present or are showing disease symptoms.

Do you plan to use mulch in your garden?

Mulch helps prevent weeds that will decrease your garden’s production by competing with the vegetable plants for water, nutrients and sunlight. In addition, some weeds harbor diseases and insects that attack vegetable plants.  Mulch also helps conserve soil moisture.

Several types of commercial mulch are available, or you can use newspapers for the mulch. Start with five to eight layers, adding more layers as the newspapers decompose to prevent weed growth throughout the growing season.  Be sure to use only newspapers printed with soy-based ink and avoid using the glossy inserts.

If you have other gardening questions visit www.extension.org or contact the Hardin County Cooperative Extension Service at 270- 765-4121. 

For more information on growing vegetables, request our publication, “Home Vegetable Gardening in Kentucky” (ID-128). It is available from your local Extension Service office, or from the UK Web site at http://www.ca.uky.edu/agc/pubs/id/id128/id128.htm.

Educational programs of the Cooperative Extension Service serve all people regardless of race, color, age, sex, religion, disability or national origin.

NOTE:  The Lincoln Trail Master Gardeners are at the Extension Office EVERY AFTERNOON to answer your gardening questions.  Please call 270.765.4121 to consult with a Kentucky Master Gardener about any gardening questions.

Gardeners’ Tool Box Series:

How Will My Plant Die? - April 19, 2011

Everything dies at some point.  But not every plant has to die an untimely death.  Learn what you can do as plant-parents to keep your children out of harm’s way.  Nutrition, care of the newly planted, and raising the green teenager will set you on the path to long-lived plants. Registration ($7) and payment must be received by April 15. Class is held at the Hardin County Extension Office beginning at 6:30 p.m. 

Spring Flower Arranging - May 3, 2011

Back by popular demand!  Assemble a  small springtime flower arrangement.  The perfect gift for Mothers’ Day or give the class as a gift.  All the supplies for the arrangement will be included in the class fee. Registration ($10) and payment must be received by April 22. Class is held at the Hardin County Extension Office beginning at 6:30 p.m. 

Don’t Forget about the Lincoln Trail Area Master Gardeners’ 13^th Annual Plant Fair: MAY 21^st from 9 a.m. – 3 p.m. at the Hardin County Extension Office, 201 Peterson Drive, Elizabethtown.

Mistletoe: Tree Thief, Holiday Tradition

Once autumn leaves have fallen, mistletoe becomes highly visible on large trees throughout Kentucky. Phoradendron, the scientific name for this parasitic plant, means tree thief. You can commonly find these small leafy plants on twigs and branches of many hardwood species in the southern two-thirds of the United States. Mistletoes extract water, mineral elements and food from their host tree by way of a parasite nutrient-uptake organ; hence the name, tree thief.


Mistletoes’ use in holiday traditions has roots in pagan times. Its parasitic nature and the fact that it appears to be alive while the host tree appears dead, led some to believe mistletoe mysteriously held the life of the tree during winter. Druids harvested mistletoe in a special rite, never letting the plant touch the ground, then hung it in their homes for good luck.


Our modern-day mistletoe holiday tradition likely originates with a mythological Norse goddess of love and beauty. Frigga, whose son was restored from possible death by mistletoe, was thought to bestow a kiss on anyone walking beneath one. Today, when two people meet under the mistletoe, tradition suggests they must exchange a kiss for good luck.


Phoradendron, the most common mistletoe growing in Kentucky, resembles another species that grows in Europe. It has simple, fleshy green leaves arranged oppositely on the stem. Stems are short and more branched than the host tree, so mistletoe often appears as a spherical bunch of dense vegetation. These bunches may be a foot or two in diameter and are located high in the tree for better sunlight exposure. Mistletoe berries range from white to straw-colored to light red. Birds eat the fruits, reportedly toxic to human and animals, then deposit the seeds onto branches where they germinate and penetrate the host tree.


Since birds tend to roost in open-grown trees, mistletoes do not appear as frequently in forest trees. Generally, they do not cause much damage, although they can be harmful to a tree already under stress. If mistletoe appears on landscape trees or other trees in the urban forest, you can control it through pruning.


For more information about tree parasites and diseases, contact the Hardin County Cooperative Extension Service by phone: 270.765.4121, email: Amy.Aldenderfer@uky.edu or on the web: www.hardinhort.org. Educational programs of the Cooperative Extension Service serve all people regardless of race, color, sex, religion, disability or national origin.