For archival purposes only. Links, contact names and organizations may have changed.

Answers to popular current questions from the Master Gardener Helpline (1-800-639-2230).
A link is made to those UVM Extension leaflets (EL,GD,etc.) available on the web. All leaflets are available through mail order or in person from UVM Extension offices (see theirPublications Catalog).

Vermont Hardiness Zone Map (link to UVM Extension)
New England Hardiness Zone Map (link to UConn)

POSTED 3/9/01

• March is a good time to obtain soil test kits so you are ready to use them when Spring finally does arrive. Call the Helpline at (802)656-5421 or 1-800-639-2230 and we will send a kit out to you. All instructions are in the kits, along with cost, which is currently $10.00 for a basic lawn or garden test. The early bird gets the results back fastest.
• There have been some calls about carpenter ants in homes. This can be a serious problem. There is a leaflet about carpenter ants, EL10. A sample of insects should be sent to Vt Dept of Agriculture or the Helpline, and positive identification made before other action is taken. Because of the damage possible, contacting a professional exterminator is recommended.
• The time to prune crabapples and lilacs during dormancy is upon us. For expert hands-on training, two opportunities are soon available, both being held at the UVM Horticultural Research Farm.

POSTED 4/30/01

• This is the information collected for the helpline volunteers and the Lake Friendly committee by Judy Goodyear MG:
  • CORN GLUTEN ( used as an organic pre-emergent) can be found:
    1. Gardener's Supply - 25 lbs/$37 -Company name Fertrell, brand name Weedzstop
    2. Agway - 5 lbs/$10.49
    3. Four Seasons - no corn gluten
    4. Depot Home and Garden - same as Gardener's Supply
    All recommend 20 lbs./1000 sq. ft.
  • NO P FERTILIZER - none of the above stores carry this but Oliver Seeds in Milton (802-893-4628) formulates and distributes this in NH and Maine. Perhaps if there is enough call for no P fertilizer, the stores will carry it. Oliver Gardener (owner of Four Seasons) said that the company Osmocote also formulates and distributes a no P fertilizer.
  • All of these stores carry fertilizers with N over 50% WIN.
  • None of these stores emphasize soil testing before applying fertilizer.

• For more information on grafting visit a past Vermont Apple Newsletter: http://orchard.uvm.edu/uvmapple/newsletter/1998/vtapple041398.htm

POSTED 5/8/01

• This is the time when the serviceberry (Amelanchier) is blooming, and that means also that the Gypsy Moth eggs are hatching their tiny larvae. If you see any of the egg masses that haven't hatched yet, they are bright yellow to buff color, 3/4 to 1 1/2 inch ovals, found on the lower trunks of trees, buildings, fences, etc. and should be scraped off and destroyed. See EL 55 for all the details.
• Another insect problem that we get calls about every year is the Euonymus Caterpillar. This larva of the European spindle ermine moth hatched last August already, and spent the winter in its eggshell on the twig bark and in the bud axils. It begins feeding now in the Spring, within a small web, and the web and the colony will expand as the summer progresses. By the time they are noticed, the web is quite large and dense and must be shredded with a tool or with high pressure water, and then a Bt insecticide can be sprayed on. See EL 256 for the full story.
• Moles are a hot topic again this Spring, same as last Fall. The Helpline can suggest that the homeowner try mole traps, cats, and stepping on the tunnels and mounds to flatten them. Studies have shown that moles eat mostly earthworms, some grubs, and not the roots of the grass. They actually are aerating the lawn, unsightlty as it may be. They are an important part of the food chain and only live a year or two. Using insecticides on the lawn kills the earthworms as well as the grubs, so the moles may go away (and maybe not), but so will birds you may be wanting to have around to help eat insects. If insecticides are the choice, see EL 1, White Grubs, and EL 37, Japanese Beetles, for in depth information and proper timing of application to be effective.

POSTED 5/21/01

• We received, at the Helpline, some insect specimans that seem to be new to the area. A Master Gardener from the Alburg area brought them, and said several folks are dealing with the problem there. Margaret Skinner identified them as Lily Leaf Beetles, and provided a website for further information. It is http://www.uri.edu/ce/factsheets/sheets/lilyleafbeetle.html. These beetles are native to Europe, but have been in the Montreal area since 1945, and first sighted in Cambridge, Mass., in 1992. They are bright red on the body, with black legs, head, antennae, and undersurface. They are excellent fliers and hiders. They feed on Lilium species, Fritillaria, Solomon's seal, bittersweet nightshade, potato, Nicotiana, among others. However, they lay eggs and develop only on Lilium species and species of Fritillaria. So be careful when sharing plants or transplanting in your own yard. Hand-picking adults is recommended if you have only a few plants. Neem can be useful on the first instar larvae to kill them, but only repels adults. It would have to be repeated every five to seven days after egg hatch. There are studies being done with biological controls. (posted 5/21/01)

POSTED 6/8/01

• Rhododendren leaf samples have been coming in with browned edges. Ann Hazelrigg, plant pathologist, has noted that no fungi or insects were found, so the problem is suspected to be damage from the wet year last year. Look for new growth to be healthy, clip out dead portions, fertilize with an acidic fertilizer, and help out with watering if there is a dry spell this year. If no new growth, the plants may be dead due to wet feet last summer.
• Pear thrips defoliation of maple has been a problem in some areas of Vermont.
• Swarms of maple leaf cutters have been noted at elevations of 1300 feet. (EL 34). These pests cause holes in foliaage. In large trees, control is not warranted.
• Leafspots from apple scab (GD 17) and cedar apple rust (bright orange) are appearing on apple hosts, hawthornes, etc.
• Hail injury from last week of May will show up on newly developing fruits as scars on shoulders of blueberries, apples, etc.
• There is a possibility of an infestation of the viburnum leaf beetle, Pyrrhalta viburni. It was found in Morrisville, VT, this spring, and may be in the Grand Isle region. Please be on the lookout for it. For more information, visit http://www.gov.on.ca/OMAFRA/english/crops/facts/vlb.htm. If you find the larvae, pick them off and send some samples to the Helpline.

POSTED 6/15/01

• Still some scattered frost last week so plant injury on succulent growing tips may be apparent.
• Slugs are going crazy with some of the wet weather
• Watch for striped cucumber beetles (EL 68) and damage as new plants/seedlings emerge. Check out the EL leaflet on these beetles, their damage and the Brieflet for Vegetable Insects and Diseases will have control measures.
• Slime molds (GD 22) may be a nuisance in some wet areas on bark mulch
• With cool temps at night, cucurbits will tend to produce more female flowers that male. If there are no males available, the flowers will not be pollinated and therefore no fruit.
• As peonies beging flowering one may see botrytis or gray mold killing the tight flower buds if the weather is wet. Usually just clipping out the infected buds and letting the next develop fine in drier weather is the best approach.
• There have been reports of aphids on new succulent tissues. Try Safer's soap for an organic control.
• Diseases have been at a minimum this year compared to last year. Since we have had some recent rain, more leaf spots on trees and shrubs are showing up. Most of the time it is not necessary to control these with a fungicide.
• There have been some calls about leaf tying catipillars. The organic control would be to use Bt Dipel or handpick. The Dipel will not work if the feeders are sawflies so if in doubt get an ID. the sawflies would not be associated with any webbing, just voracious feeding.

POSTED 7/5/01

• Four-lined plant bug damage (EL148) apparent on mints, daisies, hydrangea, basil, many ornamental flowers and herbs. The angular leafspots look like a disease but they are feeding damage.
• Birch leaf miner (EL 2) damage obvious on birches. Too late to control now. Do that next year when the mines are first noticed. Keep up the vigor of the trees.
• Lilac leaf miner (EL 16) injury should be obvious. Check out the leaflet. There is a leaf mining phase and a leafrolling phase. Too late to control now.
• Armyworms (EL 56) are stripping grass species (this includes sweet corn) in some areas. Hand pick or use insecticide if severe and insects are still small, less than an inch.
• Tomato foliar fungus diseases although gardeners will not be seeing leafspots yet, spraying for these diseases usually begins now since we have accumulated enough degree days for the fungus to become active. Spray fungicides now and repeat on a week to 10 day schedule for control. Organic options are copper, otherwise, chorothalonil (Bravo). To lessen the disease, stake tomatoes to improve air circulation.
• Found black leg on potato. This is a black rot on the stem of potatoes that is gross and slimy. It is usually a hit or miss disease and is caused by a bacteria. There is no control other than good cultural practices.
• Brown rot still showing up on stone fruits. Too late to control with fungicides now. Causes blossom blight and gummosis on stems of plants.
• Japanese beetles (EL 37) out now. Use Rotenone or Sevin. Do not recommend traps.
• Colorado potato beetles (EL 65) all life stages should be present. Handpick, kill eggs and control young larvae.
• Fruit drop may be apparent in apples due to plum curculio damage (EL 97) or a normal phenomenon called June drop when the tree sacrifices extra fruit since they can’t ripen all the seeds produced.

POSTED 7/6/01

• new Armyworm leaflet (Adobe Acrobat document)
• EL 56
• COMMON ARMYWORM ALERT (adapted from Brian Caldwell, Cornell Extension) Vegetable growers, particularly those who grow rye, other small grains, or sweet corn, need to be aware that there have been severe infestations of common armyworm this year in the northeast, from NY to Maine. This pest sometimes blows up from the south and in most years is not a problem. However, this year is evidently an exception, so keep a closer eye than usual on your sweet corn plantings, and any vegetables near fields of rye or other small grains. The pest is a caterpillar, and if you have an infestation you will see thousands of them. They can be controlled with pesticides that are labeled for caterpillar pests on your crop. Options for many crops would include Warrior, Larvin, Sevin, or Bt. Reports indicate that Bt products containing the azawai strain are the most effective type of Bt to use against armyworms.
• COMMON ARMYWORM --John Howell and Pam Westgate (from Ruth Hazzard's IPM Vegetable Newsletter) There are numerous reports of common armyworm in turf and hay crops, in many areas of the state. This insect also attacks corn and, occasionally, some other vegetables especially peppers. The mature caterpillar is about 1 1/2 inches long, greenish yellow to brown, with a dark stripe along each side. At this time it appears that the caterpillars are full size and will likely pupate soon. Therefore,damage from this generation should not continue much longer. These are heavy feeders on the leaves, in the whorl and in the ear. Damaged leaves appear to have been shredded and this is characteristic of both the common and fall armyworms. Larvae enter fruits of pepper and can cause extensive damage. Typically, damage begins near the edge of a field as the caterpillars move in from neighboring fields or grassy or weedy borders. This is likely to happen when they use up their food supply and move on to new areas. Be particularly watchful in fields that border hay. Available insecticides for corn include Warrior, Spin Tor, Larvin, Ambush and Lannate. Apply in 75 to 100 gallons of water per acre. Make two applications five to seven days apart when damage exceeds 15% in the whorl or pretassel stages. In peppers damage is more likely to occur from fall armyworm, but a second generation of common armyworm is possible. Orthene, Poounce, Spin Tor, Confirm and Lannate are labeled. Bacillus thuringiensis, while available and effective on small larvae, is ineffective on the large larvae that are causing the damage out there now. See the New England Vegetable Management Guide and the label for more information. Growers may want to apply a treatment to the edges of fields to intercept migrating caterpillars.

POSTED 7/27/01: The weather patterns have brought warm temperatures with rains which means perfect disease conditions! Continue to look for:

• Tomato foliar diseases (GD18) showing up on lower leaves first. Info is in leaflet and control info in the Brieflet. Organic control is copper fungicides and Bravo for conventional control. These fungicides will not cure the leafspots already on the plant but will protect new tissue if sprayed on a weekly-10 day schedule. These diseases typically hit earlier varieties harder.
• Lilac leaf miner (EL 16) browning and rolling leaves-look at the EL leaflet for info and control
• 2 spotted spider mites causing white stippling and bronzing of several species including phlox, greenhouse tomatoes, etc. They prefer hot dry weather. Try Safer’s soap but watch for phytotoxicity.
• Tomato hornworms should be showing up-handpick and destroy.
• Look for imported cabbageworm larvae (EL63) on the undersides of crucifer foliage. Control while small by handpicking or by spraying Dipel. See EL leaflet for more info.
• Rust on peas and on sunflower lower leaves. Spores are obvious on lower leaves with handlens. Use sulfur if severe.
• Colorado potato beetle-all lifestages present! Crush eggs, handpick larvae and adults. Potatoes can withstand a fair amount of feeding but they can multiply rapidly!
• Rapid browning and death of lawns can be a result of chinch bug (EL191) or bluegrass billbug. Check out EL leaflet on hairy chinch bug and how to sample for them, so homeowners can try on their own.
• Apple maggot traps should be out now in home orchards.
• Squash bugs (EL83)may be causing wilting at the base of squash leaves. Check out the EL leaflet.
• Blossom end rot (GD1) may be showing up on the first tomato fruits with a brown blossom end. Try to lessen water fluctuation with mulching and watering. Typically, the next fruit are fine.

POSTED 8/29/01

• Some raspberry disease and pest information:
  • The following is a link talking about spur blight and fireblight in raspberries. Control recommendations are given. http://www.extension.umn.edu/distribution/horticulture/DG1152.html
  • Here is some info on cane and tip borers (EL13)
  • Anything you can do to improve air circulation will help with the diseases.
  • Applying lime sulfer in the spring is a good practice.
• Viburnum Leaf Beetle -The latest exotic pest to reach Vermont
  by Margaret Skinner, Entomologist, UVM Entomolgy Research Laboratory

  The viburnum leaf beetle, Pyrrhalta viburni (Paykull), was detected in Vermont for the first time in the fall of 2000 along the shore of Lake Champlain in Burlington. Originally from Europe, it was found first in North America in 1947 in Ontario, Canada. It has been in Maine, New York and New Hampshire for several years. This year heavy damage by this beetle has been reported in several northern Vermont locations, and it has been sighted in six different northern and central counties. Considering that viburnum is a favorite landscape shrub, this pest could have a significant impact in this state. If left untreated, a bush can be killed if it is heavily defoliated for two to three years.

  The larva and adults of this insect feed on the leaf tissue between the veins so that the leaves look skeletonized. They overwinter as eggs, which hatch in May. The larva are very small and darkly colored when they first hatch. Early feeding damage looks like small pin pricks or holes. As they mature larvae can range in color from brown to pale green with dark brownish dots. By June the skeletonizing of the leaves is obvious. In June, larvae drop off the leaves to pupate in the soil. Adult beetles emerge in late July and continue to feed. They are brown and less than half an inch long. Females lay eggs from late summer to the first frost. They make a hole in a small twig, and lay several eggs in each hole, which is then covered with a mixture of chewed wood and excrement. Egg laying holes can be found in a straight line on the underside of the current season's growth. One female can lay up to 500 eggs per season.

  This pest feeds on all species of Viburnum, including European highbush cranberry (V. opulus), wayfaring tree (V. lantana), arrowwood (V. dentatum), and American highbush cranberry (V. trilobum). Some species are preferred more than others, but all of them are susceptible.

  The simplest way to minimize the damage from this pest is to inspect your viburnum bushes anytime after the eggs have been laid and before they hatch. In most areas of Vermont that would be from late October until April. The egg masses appear as rows of small bumps on the underside of the most current twigs. Any infested twigs should be pruned and destroyed. Bushes should also be inspected in the spring to see if larvae are present. If the infestation is small it should be possible to destroy these young larvae by hand before heavy damage occurs. adults can also be picked off, but this is most effective if done in the morning because in the warm afternoon they are apt to fly off when the leaf is disturbed.

  As a last resort, there are several insecticides that are effective against the viburnum leaf beetle. control is most effective if applied against the larval stage. Products containing pyrethrins are the least environmentally damaging and most effective for controlling the larvae.

  For more information about viburnum leaf beetle, contact Dr. Margaret Skinner at mskinner@zoo.uvm.edu or call 656-5440

POSTED 11/8/01

• VOLES
  Now is a good time to think about preventing some of the vole damage similar to that which was such a problem last winter. We are already receiving calls regarding vole activity in perennial beds and fall planted garlic beds. Callers have left the leaves on the beds for mulch, and have heavily mulched their garlic beds. Mulching should wait until the ground is frozen, so as to discourage the critters from finding a warm home. If you have shrubbery mulched, pull back the mulch, and replace after ground is frozen. Mouse traps can be set with apple slices, or with peanut butter mixed with oatmeal, and set out on fresh runs. Deep watering your shrubbery before the ground freezes is helpful to the plants and may also discourage critters.
• GYPSY MOTHS
  Before the snow flies, when you are taking Autumn walks, keep your eyes open for fuzzy patches at the bases of trees. These are the egg masses of the Gypsy Moth. The egg masses look like someone cut a patch from a camel hair coat and stuck it on the tree bark. The female Gypsy Moth does not fly, so egg masses are low on trees. There they are also covered by snow to survive the winter and hatch out next Spring when the serviceberry blooms. It is easy to scrape off the egg mass now and crush it or put in soapy water.

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