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).

Seasonal Tips archives: 2001, 2002, 2003, 2004 , 2005 , 2006

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

POSTED 12/3/07

Perennial Plants- If you haven’t already done so, cut back the dead tops of herbaceous perennials and remove them from the garden. Spent flowers and seed heads of plants such as sedum, coneflower, black-eyed Susan can be left standing to provide food for wild birds and winter interest in the garden. Plant crowns can be mulched with shredded leaves to a depth of 2-3 inches, but avoid using leaves of trees which showed foliar disease symptoms earlier in the year.

Roses- Provide winter protection for hybrid roses by mounding an organic mulch 12 inches deep around the base of the plant, held in place by a frame if necessary. Climbing roses should be untied from their trellis and the canes pinned to the ground using landscape staples. Though all rose canes can be cut back to a manageable length to facilitate mulching, most pruning should be done in late winter or early spring when new buds have formed and the extent of winter damage can be assessed. Check this link for more information on winter protection for roses: http://www.uvm.edu/%&Euvmext/publications/oh/oh4.htm

Woody plants- Most deciduous trees and shrubs can be pruned at any time during the dormant period. An exception is spring-flowering shrubs; next year’s flower buds are already formed, so delay pruning these until after they bloom. Delay pruning clematis vines until the new buds are evident in the spring. To avoid damage from voles and field mice, mulches around the base of trees and shrubs should be no more than 2-3 inches deep and pulled back away from the bark.

Houseplants- Cooler temperatures and diminishing daylight will put houseplants into a resting period. Regular fertilization can be greatly reduced or stopped altogether at this time. Be careful not to overwater; allow the top layer of soil to dry out between waterings. If any of your houseplants had an outdoor “summer vacation”, monitor carefully for pests. Call the Master Gardener Helpline at 1-800-639-2230 for specific recommendations.

Seasonal plants- Poinsettias are a common feature of Vermont homes in the holiday season. Proper care will increase their useful life and maximize your enjoyment of these festive plants. Check the following link for a detailed discussion of poinsettia care, and for the fanatics among us, a guide to keeping and reblooming them for a second season: http://www.hgic.umd.edu/_media/documents/hg30.pdf

Proper selection and care of cut Christmas trees is critical to ensuring a safe holiday. Freshness is key! The fresher the tree, the less likely it is to become a fire hazard in your home. The best way to make sure you have a fresh tree is to cut it yourself at one of the many local “choose and cut” Christmas tree operations. Check the link below for a list of plantations near you: http://www.vermontagriculture.com/buylocal/buy/christmasTrees.html

If you can’t or choose not to cut your own tree, there are still steps you can take to make sure you get the freshest tree possible and to keep it that way during its stay in your home. Check the following link for a comprehensive guide to the selection, care and safe display of cut Christmas trees: http://www.hgic.umd.edu/_media/documents/hg45_001.pdf

POSTED 10/22/07

Halloween is fast approaching, and many parts of the Vermont have yet to experience a killing frost. Nevertheless the handwriting is on the wall, and the end of the gardening season is just around the corner. Now is the time to undertake those end-of-season tasks that will make next season easier and more rewarding. Check the following link for a general discussion of fall garden cleanup:

http://www.uvm.edu/%7Euvmext/publications/oh/oh3.htm

It’s probably a bit late to divide herbaceous perennials- it’s generally best to allow at least 4-6 weeks before the ground freezes for the plants to become established. For the same reason, avoid transplanting evergreen shrubs and trees at this time. It should be OK to plant container stock- and take advantage of those nursery clearance prices- Just be sure to keep your new acquisitions well-watered before freeze-up. That goes for the established plants in your landscape as well, especially for evergreen plants which will continue to lose water through their leaves all winter.

Tender roots, bulbs, rhizomes and tubers should be dug carefully after the tops yellow or are killed by frost. Check the following link for specific instructions on preparing and storing roots for replanting next year:

www.extension.umn.edu/distribution/horticulture/DG1117.html

Finally, once the garden is put to bed for the winter, don’t forget your tools! Cleaning, sharpening, and oiling now will save time and trouble later on. And if you had disease problems this year, wiping your tools with alcohol or a 10% bleach solution will help prevent reintroducing disease organisms into the soil.

POSTED 9/7/07

Many areas of Vermont have been experiencing an extended period of dry weather. While we’re not officially in a “drought”, many people are noticing wilting and browning of vegetable and ornamental plants and early fall color, leaf edge browning and leaf drop from deciduous trees. Because water is a scarce resource, home landscape irrigation should be prioritized. Most important are newly planted (less than three seasons) shrubs and trees; least important are established lawns. Mature trees are generally able to withstand periods of dry weather without permanent injury. The goal of watering is to thoroughly moisten the root zone of target plants, generally the top 4-6 inches of soil, at least once per week during dry weather. Check the following link for a comprehensive discussion of watering:

http://www.hgic.umd.edu/_¬media/documents/hg85.pdf

Winter squash are ripe when they are full-sized, fully colored and the rind cannot easily be dented with a fingernail. Remove ripe fruits from the vine, leaving a 4-5 inch “handle”, and store in a cool place until ready to use.

If the Labor Day weekend is past, can the first hard frost be far behind? Extend your harvest by ripening some of that crop of green tomatoes indoors. Before the frost, pick sound, undamaged fruits which have reached full size and begun to whiten or color. Place them in boxes no more than 2 layers deep, or simply on a shelf in a cool, moderately humid location out of direct sun. Ripening can be accelerated by placing tomatoes in a paper bag along with an apple or banana. Check the link below for more information:

http://www.extension.umn.edu/info-u/nutrition/BJ763.html

POSTED 9/4/07

INSECTS:

Adult Viburnum Leaf Beetles will be found feeding on preferred viburnum species until frost. A late-summer application of a labeled insecticide may be needed to control heavy feeding. Monitor for egg-laying sites and prune out and destroy affected twigs. Consider replacing susceptible plants with varieties less favored by this serious pest. Click these links for more information:

www.uvm.edu/extension/publications/el/el260.pdf
www.entomology.cornell.edu/Extension/DiagnosticLab/IDLFS/VLBfactsheet2003.html

Fall Webworm is starting to appear on a variety of shrubs and trees. These caterpillars spin silky webs enclosing the terminal branches. They feed on the leaves inside the web, which they enlarge as they grow. When small, the caterpillars can be controlled with the biological insecticide BT (Bacillus thuringiensis) sprayed on the leaves near the web. Larger webs can be pruned out and crushed underfoot, or blasted apart with a forceful jet of water from a garden hose. While unsightly, Fall Webworm feeding rarely affects the long-term health of established trees. Click the following link for more information:

www.uvm.edu/extension/publications/el/el145.htm

VEGETABLES:

Blossom End Rot of tomatoes is a physiological disease caused by a deficiency of available calcium in the developing fruit. The condition can reflect a lack of calcium in the soil or, where soil calcium is adequate, a reduced availability of the nutrient due to improper pH or uneven watering. Have your soil tested and amend as required, and be sure to provide regular, adequate irrigation when nature does not cooperate. A couple of deep waterings per week during dry periods is better than daily light watering. Call the MG Helpline at 1-800-639-2230 to order a soil test. Click the following link for more information on garden diseases:

www.uvm.edu/extension/publications/gardendisease/gd1.htm

LAWNS:

Fall is the best time to fertilize your lawn. With heightened public concern over the possible contribution of home lawn fertilization to phosphorus pollution in aquatic ecosystems, the importance of soil testing to assess fertilizer needs is greater than ever. Sid Bosworth, UVM Extension Agronomist, suggests that homeowners test their soil every 3-4 years with an eye to phosphorus levels: “If phosphorus tests high or greater, there is no need to add additional P and there could be adverse environmental consequences if you do. But if soil test levels are low in P, it is important to provide adequate amounts to assure good leaf and shoot growth to improve turf density.” (Bosworth 5/04) Call the MG Helpline at 1-800-639-2230 to order a soil test kit and click the following link for more information on home lawn management:

www.uvm.edu/%7Euvmext/publications/lakefriendly/lakefriend12.pdf

POSTED 8/1/07

INSECTS:

Japanese beetles continue to feed on a variety of ornamental, fruit and vegetable plants. Hand-pick the adults early in the day when they are moving more slowly, brushing them into a wide-mouthed container of soapy water.

Early August is the best time to control newly hatched beetle grubs in lawns and flower gardens. Apply a labeled insecticide containing the active ingredient imidicloprid, and water in well. Controlling grubs now will reduce direct feeding damage to turfgrass roots and the risk of secondary damage from skunks and moles which feed on grubs in the soil.

Click these links for more information on controlling Japanese beetle grubs and adults:

White Grubs www.nysipm.cornell.edu/publications/grubs/index.html

The following URL is to a new website on the current armyworm situation. http://pss.uvm.edu/vtcrops/?Page=articles/armyworm07.html

VEGETABLES:

Tomato blights, wilts and leaf spot diseases are promoted by wet weather and high humidity. Remove affected foliage and discard in the trash; do not compost or leave in the garden. Thin plants by removing sucker growth to improve air circulation. Cover the soil with an organic or synthetic mulch to prevent splashing of infected soil onto the leaves, and avoid overhead watering. If disease is a problem this year, consider rotating tomatoes to a different part of the garden next year, and plant disease-resistant varieties.

Click these links for more information on tomato diseases:

Tomato Blight Diseases. (1992) Symptoms, cause, and control of tomato blight. 2 pages, *, GD 11. http://www.uvm.edu/~uvmext/publications/gardendisease/gd11.htm

Tomato Wilt Diseases. (1992) Lifecycle and control measures for these fungal diseases of tomato. 1 page, *, GD 18 http://www.uvm.edu/~uvmext/publications/gardendisease/gd18.htm

PERENNIALS:

Consider dividing overgrown spring and early-summer blooming perennials which have passed their flowering period. Dividing and replanting in late summer or early fall will allow root systems to recover before the ground freezes. Mid- to late-summer bloomers are best divided in the spring- just remember to mark their locations before the top growth disappears!

Now is also a good time to dig and separate overcrowded iris. Inspect iris tubers for rot and borer damage, and remove damaged sections before replanting.

Click these links for more information on growing and propagating perennials:

Growing Perennials in Vermont. (1987, revised 1997) Culture of perennials. 2 pages, *, OH 23 http://www.uvm.edu/~uvmext/publications/oh/oh23.htm

Propagation of Perennials. (1989, revised 1997) Propagation of plants, by method. 2 pages, *, OH 28 http://www.uvm.edu/~uvmext/publications/oh/oh28.htm

LOOKING AHEAD:

Plan now to take advantage of the prime fall season to fertilize or renovate your lawn! Check out the publication below:

Lawns. (2001, revised 2004) Offers lawn care suggestions, including establishment, fertilization, watering, mowing, and insect, disease, and weed control tips. http://www.uvm.edu/~uvmext/publications/lakefriendly/lakefriend12.pdf

Capture your garden program in photos!
excerted from" Vt Community Gardens Network " newsletter

It's midsummer and gardens across Vermont are in full bloom. Although we're all busy keeping up with weeding and harvesting, be sure to take some time to capture photos of your garden and garden participants. The photos can be used in displays to highlight your garden project, with grant proposals, and to help build community support.

So bring along your camera, especially on cloudy days when color saturation is best. When you're in the garden, ask your fellow gardeners to pause for a few moments and pose with the fruits of their labors. Experiment with close-ups and fun compositions.

Here are some links with additional garden photography tips:

"Taking great garden photos" http://www.kidsgardening.com/growonder/photo.php

"The rule of thirds" http://www.plantea.com/garden-photos-thirds.htm

"How to take better garden pictures" http://www.flower-gardening-made-easy.com/take-better-garden-pictures.html

POSTED 6/28/07

ROSE CHAFER beetle adults are swarming in yards and eating perennials, shrubs and trees.
JAPANESE BEETLE adults will be joining them soon. These adult beetles can best be dealt with in the early morning while they are still slow. Brush them off into a container of soapy water held below, as they roll and drop for defense. Then, during late July to early August, apply a chemical product, containing imidicloprid as the active ingredient, to the lawn for destroying the young larvae as they hatch. That is the ideal time to treat lawns for grubs.

For more information about Rose Chafer and Japanese beetle, go to the Master Gardener home page, click on 'Links' and click on 'Entomology Leaflets' to find the factsheets alphabetically.

LILY LEAF BEETLE is a bright red beetle about 1/4inch long that, as an adult, eats leaves of Asiatic and oriental lilies, most varieties. It also lays eggs on the undersides of the leaves that are left, and the young larvae feed on those remaining leaves when they hatch. As with other beetles, knock off as many as possible into a container of soapy water. To search for and crush larvae, lightly grasp the bottom of the lily stem and slide your hand up the stem, bending the leaves back to expose their undersides and anything chewing on them. If all else fails, spray the leaves, top and undersides, with Neem oil as directed on the label.

For more information about the Lily Leaf Beetle, go to the Master Gardener home page, click on 'Links', 'Vermont Links', 'Vermont Agency of Agriculture', and then 'What's Bugging You?'.

WILD CHERVIL, WILD PARSNIP, and JAPANESE KNOTWEED ("BAMBOO") are invasive plants to watch for and destroy. They all require several seasons and a lot of vigilance to control.

Wild Chervil is best worked on before it goes to seed in mid-June. After that, leave it alone

Japanese knotweed can be starved by cutting it back 4 times a season. This may take up to 5 years to take effect. For more, go to same as Wild Chervil.

Wild parsnip should be cut below ground level with a sharp shovel. Wear protective clothing, as the juice from the plant can cause burns on the skin when exposed to sunlight. Go to: http://www.uwex.edu/ces/wihort/gardenfacts/XHT1083.pdf

For more info, go to the Master Gardener home page and click on the "Invasive Exotic Plants'' button near the bottom of the home page.

Contact Vermont Master Gardener at master.gardener@uvm.edu.
Contact webmaster sarah.kingsley@uvm.edu with questions or comments about this web site.

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