Home Gardener Headlines - Summer 2011
Dear Home Gardener,
Here we are in "official" summer, and the weather is finally accommodating our plants. Sunshine, rain, sun, rain....but we know we're not home free just yet! Besides, we're still recovering from the wicked drought and heat of 2010, which has left trees badly stressed and open to dieback, fire blight, bacterial leaf scorch, and other ills, depending on the species. Most plants pulled through, and may be able to regain some of their vigor this year, but no doubt some grand trees will be lost. In the end, we really do not control nature!
Each gardening season is a new adventure. We hope we've offered you some new information or insights in these pages. As always, we encourage you to call with your garden and landscape questions.
Beth Finlay, Master Gardener Coordinator
Nancy Bosold, Extension Educator
Had Your Shots? Not Flu Shots...TETANUS!
All gardeners should check periodically that their tetanus shots are up to date. Tetanus is a bacterium that is naturally present in soils and soil amendments and is widespread in the environment. Minor breaks in the skin provide openings for the bacteria to enter the body. Symptoms can be quite severe or even fatal.
Many older Americans were never vaccinated against tetanus and are particularly susceptible. Younger people may hav ehad childhood immunizations, but have let them lapse. Tetanus boosters are required at least every 10 years to keep the protection active.
Gardening and other outdoor activities put us in regular exposure to both the conditions and the germs that cause tetanus. Don't take chances. Update that tetanus shot!
Written by Beth Finlay, Master Gardener Coordinator
Residents Encouraged to Participate in Bat Survey
Pennsylvania Game Commission biologists are seeking assistance from residents in a regional monitoring effort to collect bat maternity colony data this summer. This monitoring is especially important due to the mortalities in bat populations throughout the northeastern United States, including Pennsylvania, being caused by White-Nose Syndrome (WNS).
"WNS primarily kills during the winter, but the true impact of WNS on bat populations cannot be determined using estimates from winter hibernacula alone," said Calvin Butchkoski, Game Commission wildlife biologist. "Pennsylvanians can help us more fully gauge the impact of WNS on the landscape by hosting a bat count this summer. We are especially urging people who have ever conducted a bat count for the Game Commission in the past to redo a count this year."
To obtain applications and information on how to participate, visit the Game Commission's website (www.pgc.state.pa.us) and click on "Wildlife" in the menu bar at the top of the home page, scroll down and choose "Pennsylvania Bats" in the Mammal section, and then click on "Appalachian Bat Count" in the Reference listing. Forms on the website guide interested participants through the steps of timing, conducting a survey and submitting their findings to the Game Commission. Scout groups, 4-H clubs, local environmental organizations, and individual homeowners can all participate in this important effort.
"Pennsylvania's two most common bat species, the little brown bat and the big brown bat, use buildings as their summer roosts," Butchkoski said. "Abandoned houses, barns, church steeples--and even currently occupied structures--can provide a summer home to female bats and their young.
"Monitoring these 'maternity colonies' can give biologists a good idea of how bat populations in an area are doing from year to year. With the occurrence of WNS in Pennsylvania this year, monitoring these colonies is more important than ever."
Butchkoski noted that the fieldwork isn't difficult to do, and Pennsylvanians can play a huge role in helping the Game Commission get a better understanding of what is happening to bats this summer.
"We're looking for some help, and we hope you'll consider becoming part of the Appalachian Bat Count monitoring team," Butchkoski said. "It's a chance to make a difference for bats to get involved in the fight against WNS. Please consider lending a hand. Bats need you more than ever."
A multi-state State Wildlife Grant was awarded and is being administered by the Game Commission to investigate and respond to WNS. As part of this project, the Appalachian Bat Count contributes to the nationwide effort to collect data during summer months through maternity colony monitoring, wing assessments, and acoustic sampling.
For more information on WNS, visit the Game Commission's website and click on "Wildlife" in the menu bar at the top of the home page, scroll down and choose "White-Nose Syndrome" in the Wildlife Disease section. To report observations of sick or multiple dead bats, go to the agency's website and click on "Report a Sick Bat" in the "Quick Clicks" box in the right-hand column of the homepage.
Source: PA Game Commission News Release: survey part of national White-Nose Syndrome monitoring effort
Summer Outdoor Insect Pests
Thrips: The Invisible Biter
Have you ever been sitting outside on a beautiful sunny day and suddenly been bitten by something, but not seen what bit you? You have probably been bitten by a thrips (there is one and only one pronunciation for them: thrips. One thrips, two thrips, and so on).
Thrips are unique in that they have what are called rasping-sucking mouthparts. Thrips use their mouthparts to slash surface cells on a plant's stem, leaves, or frruit, and drink the juices that ooze from those wounds.
Thrips don't "bite" on purpose. They are just "tasting" you to see if you are a plant. They do not inject venom and the discomfort is only temporary. Most poeple who are bitten by thrips are sitting downwind from something that's blooming. In the spring and summer, magnolias and wildflowers are loaded with thrips.
Controlling thrips is fairly simple. Strong streams of water will provide some control, but insecticidal soaps will provide a more reliable means of managing this pest.
Ticks, of which they are more than 500 species worldwide, are parasitic arthropods closely related to mites. Most ticks feed on the blood of warm-blooded mammals but some species also feed on birds, reptiles, and even amphibians. Fish are apparently the only vertebrates not plagued by these little bloodsuckers.
Many species of ticks can transmit diseases (zoonoses) from an infected host to other uninfected hosts. Some of the more frequently transmitted organisms include parasitic worms, viruses, bacteria, spirochetes and rickettsias. The most important of these to Pennsylvanians are spirochetes which cause Lyme disease, and rickettsias which cause Rocky Mountain Spotted Fever.
Prevention and Control: The best advice for preventing Lyme disease and other tick-borne disease is to:
- Wear protective light-colored clothing while outdoors, including a broad-brimmed hat, a long-sleeved shirt, and long pants tucked into the socks.
- Check the body daily for the presence of ticks.
- Use tick repellents, DEET, or permethrins.
- Use forceps or tweezers to carefully remove ticks attached to the skin. Apply gentle, constant retraction of the tick where it attaches to the skin (not the body of the tick.)
- Seek immediate medical attention if signs or symptoms of early Lyme disease appear.
Self-examination is recommended after spending time in infested areas. If an embedded tick is found, it should be removed with fine tweezers by grasping the head and pulling with steady firm pressure. The tick should not be grabbed in the middle of its body because the gut contents may be expelled into the skin. the use of heat (lit match, cigarette, etc.) or petroleum jelly is NOT recommended to force the tick out. These methods will irritate the tick and may cause it to regurgitate its stomach contents into the individual, thereby increasing the possibility of infection.
Black Flies and Their Control
Black flies are pests of man and animals in many areas of Pennsylvania. They are small dark flies. Most species are 2-3 mm (1/8 inch) long.
Only the female black fly bites. All immature black fly stages (eggs, larvae, and pupae) require moving water for development since water movement provides their oxygen and food.
Black flies are attracted to their animal or human victims by the carbon dioxide and moisture present in exhaled breath, dark colors, convection currents, perspiration, perfumes and toiletries.
Black flies are annoying when numerous, even if they are not biting. They often fly into eyes, nose, ears, and mouth. Bites cause pain and dermatitis at the site of the bite because black fly saliva is toxic. Intense itching may last several days; serious allergic reactions may occur.
Probably no creature on earth can cause as much torment for its size than the tiny chigger. Tiny six-legged chigger larvae attack campers, picnickers, hikers, bird watchers, berry pickers, fishermen, soldiers, and homeowners in low, damp areas where vegetation is rank such as woodlands, berry patches, orchards, along lakes and streams, and even in drier places where vegetation is low such as lawns, golf courses, and parks. they are most numerous in early summer when grass, weeds and other vegetation are heaviest. Chiggers do not burrow into the skin but insert their mouthparts in a skin pore or hair follicle. Their bites produce small reddish welts on the skin accompanied by intense itching.
Life Cycle and Habits: Adult chiggers overwinter near or slightly below the soil and in other protected places. Females become active in the spring and lay up to 15 eggs per day in vegetation when soil temperatures at 60 degrees F. Eggs hatch into six-legged larvae, the only stage that attacks humans and animals (parasitic stage). After hatching, chigger larvae climb up onto vegetation from which they can more readily snag a passing host.
Chiggers are usually encountered in late spring and summer in areas where weeds and briars have overgrown. They lurk on grass stems, leaves, shrubbery, etc., usually in damp, shaded spots near the top of different objects close to the soil. The preferred feeding locations on people are parts of the body where clothing fits tightly over the skin such as around the belt line, waist line, under socks, or where the flesh is thin, tender or winkled such as ankles, armpits, backs of the knees, in front of the elbow, or in the groin.
Bites: Chigger larvae do not burrow into the skin, nor do they suck blood. They pierce the skin and inject into the host a salivary secretion containing powerful digestive enzymes that break down skin cells that are ingested (tissues become liquefied and sucked up). After a larvae is fully fed in four days, it drops from the host, leaving a red welt with a white, hard central area on the skin that itches severely and may later develop into dermatitis.
Control Measures: After returning from a chigger-infested area, launder the field clothes in hot, soapy water (125 degrees F) for about half an hour. Take a good hot bath or shower and soap repeatedly. For temporary relief of itching, apply ointments of benzocaine, hydrocortisone, calamine lotion, New Skin, After Bite, or others recommended by your pharmacist or doctor. Some use Vaseline, cold cream, baby oil, or fingernail polish. The sooner the treatment, the better the results.
Before going into an area where chiggers may be present, protect yourself by using a repellent such as DEET. Keep moving since the worst chigger infestations occur when sitting or laying down in a sunny spot at midday with temperatures above 60 degrees F. If possible, stick to roads and trails.
Source: Texas Cooperative Extension, Bexar County; Entomological Notes, Penn State University Dept. of Entomology
Fruit Drop and Hand Thinning
Gardeners are often surprised when small apples and other fruit drop prematurely to the ground. However, premature fruit drop is relatively common on apples and other fruit trees. The home gardener shouldn't be alarmed if the fruit tree appears healthy. The fruit drop may simply be nature's way of reducing a heavy fruit load.
Two fruit drop periods commonly occur on apples. The "first drop" occurs shortly after petal-fall and may continue for 2-3 weeks. The fruit that falls during this period is pea-sized and may be the result of poor pollination. Most apple varieties are considered self-unfruitful. These fruit varieties will produce little or no fruit when pollinated with their own pollen. Another variety (cultivar) is required for cross-pollination and fruit set. 'Jonathan' and 'Yellow Delicious' are two apple varieties which are notable exceptions. Each will produce a fairly good crop without cross-pollination. A lack of pollination may also be due to poor weather. Most fruit trees are pollinated by bees. They are most active on sunny, warm days. there is little bee activity during cool, rainy weather. Cool, rainy weather during the bloom period reduces bee activity, results in poor pollination, and may lead to fruit drop. exposure to freezing temperatures during flower bud development and bloom may also cause fruit drop.
The "second drop" usually occurs in early June. (This is commonly referred to as "June drop"). The fallen apples are approximately 1/2 to 1 inch in diameter. The second shedding of fruit is often due to the competition among the developing fruit for food, water, and nutrients. This natural thinning removes excess fruit and allows the remaining fruit to develop properly. Hot, dry weather in late spring will contribute to fruit drop.
While the number of fruit which fall to the ground as a result of natural thinning may seem quite high, additional thinning may be necessary. Trees overloaded with fruit need additional thinning to (1) obtain large, high quality fruit at harvest; (2) allow development of flower buds for next year's crop, thus overcoming the tendency for some fruit trees to bear fruit in alternate years; and (3) prevent limb breakage. Hand thinning of apples should be done within six weeks of full bloom. Leave the largest apple in a cluster unless it is damaged. After thinning, the apples should be spaced about 8-10 inches apart on the branch. Pears, plums, and apricots may also require hand thinning. Fruit should be spaced about 6-8 inches apart on the branches following thinning.
Written by Richard Jauron, Department of Horticulture, Iowa State University
Effects of Drought on Landscape Plants
We're seeing a great deal of shrub and tree damage this year, and much of it may be traceable to the record heat and drought phenomenon of 2010.
The deprivation last year caused tissue damage which will repair over a long time, if at all. Be aware of the symptoms below and just as important, of how to prevent them.
Drought Stress Symptoms:
- In a single year, moisture stress symptoms may not appear until late in the summer after extensive hot and dry windy weather. Symptoms may include leaf scorch, interveinal necrosis of leaf tissue, and finally, leaf drop (defoliation) beginning at the top of the tree.
- Extended drought stress (more than one season) can result in crown decline, twig die-back, small branch die-back in the upper crown and progressively larger branches can succumb or are vulnerable to breakage under strong wind conditions. Suckering may occur on the trunk and upper branches of heavily stressed trees; cambium death and cankers may also occur resulting in the girdling of the tree and total tree death. Another symptom of extended drought stress is heavy seed loads the year following the drought.
- Often the symptoms of drought stress are delayed. Water deficiency may cause extensive root injury in the late summer and fall. The current year's foliage may not reveal any symptoms. Conifers are an example of a plant that is already in dangerously poor health by the time it expresses symptoms of stress. In sum, the symptoms and effects of the drought may not appear until the following year when rainfall is normal
Tips for Avoiding Water Stress Situations:
Keep track of rainfall amounts at your location.
Supplement with an efficient watering system such as drip irrigation.
Scout your plants for signs of water stress and use indicator plants to assist you in measuring need for supplemental watering. Good indicator plants include Viburnum tomentosum var. plicatum 'Doublefile Viburnum', Azalea, Cornus sp. (dogwood), Forsythia, Acer palmatum (Japanese maple), Cercis canadensis (redbud), Hydrangea sp.; annuals, and herbaceous perennials. When these indicator plants are looking droopy, all of your plants probably need water.
Keep an eye on trees near normally wet areas (streams, lakes, low areas). Once their access for water has been diminished, these plants will have a great susceptibility for damage because their root systems are not sufficiently developed for mining water outside of their root zone.
In the landscape, consider designing with water use in mind and target dry areas for more drought-tolerant species.
Mulch landscape beds with 2-3 inches of well composted organic matter to maintain moisture. Do not allow the mulch to directly contact the trunks of trees, shrubs, or herbaceous plants.
Designing group plantings can provide for greater water management. Beware of over-planting; over-planting can place further stress on the soil moisture available to the plantings.
Do not plant during drought seasons. Hold off new landscape planting activities until the drought has subsided. This is especially true where water restrictions are activated. Maintaining the plants you presently have in the ground should be the main concern.
From Horticulture Fact Sheet "Drought and the Landscape" by Jim Sellmer, Assoc. Professor of Ornamental Horticulture, Penn State University