Yard & Garden Line News Volume 8 Number 13                                                               August 15, 2006

Features this issue: Divine Vines Ground Beetles New Hydrangea Virus Discovered at the University of Minnesota Garden Calendar Editorial Notes

Divine Vines
Nancy Rose, Regional Extension Educator, Horticulture

Campsis radicans Photo: Nancy Rose

Looking for some plants that can provide fascinating foliage, beautiful flowers, and showy fruit; can fill a large vertical area yet take only a few square feet of ground space; and can cover up the rusting remains of that '76 Gremlin parked out at the back of the lot? Look no further than vines, a wonderfully diverse group of plants that fits into all sorts of landscape situations.

Vines grow by sending out many long, flexible stems. Though vines can scramble along the ground or even cascade downwards, their typical growth habit is climbing upward. This is a great boon for those of us who have used up just about every inch of horizontal gardening space and have nowhere to go but up! Vines have several different adaptations to help them climb; it's important to know how a particular vine climbs so that you can provide the right support structure in the landscape.

Stem twining is probably the most common adaptation for climbing. As the stem tips grow they actually move in a circular pattern, seeking out a support such as a branch or wire. The vine will then twine around the support, allowing the plant to grow upward. Vigorously twining vines like honeysuckle or bittersweet can wrap around large supports such as posts, but smaller twiners such as cup-and-saucer vine need more slender supports like string or wire.

Clematis have a rather unique adaptation for climbing: twining petioles. The petioles are the stalks that hold the leaves, and they will twine around supports to help the vine continue to grow upward. The petioles are fairly short and can only twine around fairly thin supports, so give clematis a fine textured support structure such as wire fencing or nylon netting. Similar to clematis, some nasturtiums have petioles that wrap around supports to enable climbing.

Tendrils are another adaptation for climbing. Tendrils are actually modified leaves and may look like branched threads (think of peas) or small coiled springs, seen on vines such as passion flower. These tendrils wind tightly onto nearby supports and, like the twining petioles of clematis, attach best to fairly thin supports.

The Spidermen of the plant world, some vines are adapted to climbing straight up flat surfaces with the aid of either sticky holdfasts or aerial rootlets. Virginia creeper and Boston ivy have branched tendrils ending in sticky disks that act like suction cups, cementing themselves to vertical surfaces so the vine can climb farther up. Trumpet creeper can also grow straight up a phone pole or wall, but it uses large clusters of aerial rootlets to plaster itself to the support. These self-adhering vines are great for covering masonry walls, but they can be a problem on wood since the holdfasts or rootlets are tough to scrape off should the surface need painting.

Boston invy-fall Photo: Nancy Rose

Annual, Perennial, or Tender Container Plant?
Vines can be divided up into those that are annual, perennial, or tender container plants (in our climate).

Annual vines can be great fun in the garden, since they can be changed each year and don't require a permanent support structure. Most annual vines flower over an extended period, usually from mid-summer until frost. Use annual vines to cover chainlink fences, as a quick screen on trellises, or as a garden accent when grown on a decorative structure (garden shops and catalogs sell a great assortment of obelisks, free-standing trellises, and other support structures).

Quick-growing vines like scarlet runner bean and hyacinth bean are great for covering a rustic teepee made from long branches or bamboo stakes lashed together at the top-this makes a perfect play spot for kids. Annual vines can also be grown along with perennial vines, with both types providing landscape interest at different times. Try late flowering 'Heavenly Blue' morning glories with 'Dropmore Scarlet' honeysuckle for an extended blooming season, or variegated Japanese hops with large-flowered clematis for a stunning combination of flower color and foliage interest.

Grow frost-tender vines like passion flower, mandevilla, and star jasmine outdoors in containers in the summer (alone or with a fringe of annuals), then bring them indoors as houseplants for the winter. If you don't have good indoor growing conditions, you can treat these vines as annuals and discard them at the end of the season.

Perennial vines require a little more commitment - you'll need to provide a permanent support structure and regular maintenance -- but they don't have to be replanted every year like annuals. Some perennial vines develop extensive frameworks of woody stems (wild grapes can have "trunks" thicker than 4 inches at the base) which require a good sturdy trellis or arbor for support. Even thinner stemmed vines like clematis and honeysuckle benefit from a solid support, since they can produce many pounds of stems and foliage in a year. Whether simple or ornate, fences, trellises, arbors, and pergolas draped with vines are a graceful addition to any landscape. Look for pre-made vine structures in garden centers and catalogs, or build your own from cedar or treated wood.

Perennial vines generally have more multi-season interest than annuals. Some bear beautiful flowers in spring or summer (honeysuckle, clematis, wisteria), some produce attractive fruit that may be edible to birds (Virginia creeper, moonseed) or people (grapes, hardy kiwi), or remain decorative through much of the fall and winter (bittersweet, hops, some clematis). Perennial vines can also provide spectacular fall color, most notably the blazing reds and purples of Virginia creeper and Boston ivy.

Regular pruning of perennial vines will not only help keep them looking tidy and growing where you want them, but it also aids flower and fruit production. If you're nervous about somehow cutting back too much of a vine, it may help to know that wine grape growers prune off up to 80% of a grape vines exuberent growth over a growing season so the plant's energy will be directed toward fruit production. You needn't be that strict, but don't be afraid to clip off wayward stems through the summer.

Morning glory twines Photo: Nancy Rose

How they climb:
TS = twining stem
TP = twining petiole
TND = tendril
H = holdfast
AR = aerial rootlets

Annual vines:
Malabar spinach (Basella sp.) TS
Cup and saucer vine (Cobaea scandens) TS
Variegated Japanese hops (Humulus japonicus 'Variegata') TS
Moonvine (Ipomoea alba) TS
Cardinal climber (Ipomoea x multifida) TS
Cypress vine (Ipomoea quamoclit) TS
Morning glory (Ipomoea tricolor, I. nil) TS
Purple hyacinth bean (Lablab purpureus) TS
Firecracker vine (Mina lobata) TS
Scarlet runner bean (Phaseolus coccineus) TS
Black-eyed Susan vine (Thunbergia alata) TS
Trailing nasturium (Tropaeolum majus) TP Canary creeper (Tropaeolum peregrinum) TS

Tender vines for containers:
Gloriosa lily (Gloriosa rothschildiana) TS
/TND Mandevilla (Mandevilla hybrids) TS
Passion flower (Passiflora caerulea) TND Madagascar jasmine (Stephanotis floribunda) TS
Star jasmine (Trachelospermum jasminoides) TS

Bittersweet Photo: Nancy Rose

Perennial Vines: (approximate hardiness indicated, but those marked * may die back in severe winters)
Hardy kiwi (Actinidia arguta) TS, Zone 4*
Arctic Beauty kiwi (Actinidia kolomitka 'Arctic Beauty') TS, Zone 4
Fiveleaf akebia (Akebia quinata)* TS , Zone 4*
Dutchman's pipe (Aristolochia macrophylla) TS , Zone 3
Trumpet creeper or trumpet vine (Campsis radicans) AR, Zone 4
American bittersweet (Celastrus scandens) TS, Zone 3
Clematis (Clematis), many species and hybrids TP, Zone 3 or 4
Hops and golden hops (Humulus lupulus, H. l. 'Aureus') TS, Zone 4
Dropmore Scarlet honeysuckle (Lonicera x brownii 'Dropmore Scarlet') TS, Zone 3
Mandarin honeysuckle (Lonicera 'Mandarin') TS, Zone 3
Moonseed (Menispermum canadense) TS, Zone 3
Virginia creeper (Parthenocissus quinquefolia) H, Zone 3
Boston ivy (Parthenocissus tricuspidata) H, Zone 4
Grapes (Vitis hybrids; wild grape V. riparia) TS, Zone 3 or 4
Kentucky wisteria (Wisteria macrostachys) TS, Zone 4*, select only hardier cultivars such as 'Blue Moon' or 'Aunt Dee'

Ground Beetles
Jeffrey Hahn, Assist. Extension Entomologist

Typical ground beetle Ground beetles stuck on sticky trap Photos: Jeff Hahn

Ground beetles are a large group of very common insects. Most species range in size between 1/8th inch to 3/4 inch. Many of these beetles are black, although some are also brown, reddish brown and bluish black, and there are even a few that are brightly colored, especially green. Many ground beetles have a shiny or iridescent appearance. The prothoax (the area behind the head) in ground beetles is wider than the head while the wing covers are usually wider than the prothorax. These beetles have moderate length, thread-like antennae.

Most ground beetles are predators, feeding generally on a wide variety of insects. You will typically find these beetles on the ground where they are active at night. During the day they hide under all kinds of cover, such as small stones, logs, bark, leaves, and mulch. If you accidently uncover this beetle during the day, it will run quickly until it can find shelter under something. While they have wings, many ground beetles do not fly. However of those that do, they are often attracted to lights.

Ground beetles are occasionally found indoors. They often find their way inside under doors and other spaces or cracks. Those that fly may also enter buildings around windows and places above ground. Fortunately ground beetles do not reproduce indoors and are generally short-lived there. They are harmless to people and property (although it is possible to receive a pinch if one is mishandled) and they are just considered to be nuisances. If you find just one or a few ground beetles in your home, the easiest control is to physically remove them with a broom and dust pan or a vacuum. Consider releasing live ground beetles outside.

However, sometimes large numbers may occasionally be discovered in homes. This is most common during mid to late summer. There have been a few reports in central Minnesota recently about ground beetle invasions in homes. If you find large numbers, there are several steps you can take to minimize them.

First check around the outside of your home for any obvious entry points, such as spaces under doors and cracks in the foundation. Instal thresholds under doors when necessary and seal spaces using caulk or other appropriate sealant to help reduce the number of insects entering your building. Reduce potential hiding places around your home as well keeping tall weedy grass cut short. If ground beetles are a problem because they are being attracted to lights, keep outdoor lighting off or change bulbs to less attractive yellow lights.

If despite these methods, you are still having a problem with ground beetles entering your home, you can apply a residual insecticide, such as bifenthrin, cyfluthrin, deltamethrin, or permethrin. This will provide short-term relief from invading insects. Read the insecticide label very carefully to verify that the product you wish to buy allows you to treat around the exterior of buildings.

Insecticides are not useful for ground beetles found indoors. Physical removal is the best option. One method is to use sticky traps, e.g. Roach Motels. Place the traps in areas where the beetles are most common. When the insects walk across them they become stuck on the glue. You can also remove the beetles by vacuuming them as you see them. This problem in not long-lived and these beetles will eventually go away on their own.

Get the low down on this month's insect pests at Insects
http://www.extension.umn.edu/yardandgarden/EntWeb/Ent.htm

New Hydrangea Virus Discovered at the University of Minnesota
Michelle Grabowski, Regional Extension Educator-Horticulture

HCMV virus Photo credit: Ben Lockhart

A new virus, named Hydrangea Chlorotic Mottle Virus (HCMV), was discovered by Dr. Ben Lockhart and his research group at the University of Minnesota. This virus was first identified in 'Endless Summer' hydrangea by Bailey Nurseries. Multiple plants for sale at garden centers and nurseries in Minnesota were found to have a very high level of virus infection. The symptoms of HCMV infection include mottling (random patterns of light green, green, and yellow), reddening of leaf tissue, and curling or deformation of young tissue. Symptoms can be most easily seen in the spring or fall of the year and are typically not visible during summer months.

Hydrangea Chlorotic Mottle Virus infects only cultivars of Hydrangea macrophylla. This includes 'Endless Summer' 'Nikko Blue' and 'All Summer Beauty'. The virus will not infect cultivars of Hydrangea paniculata, (eg. 'Unique', 'Pink Diamond' and 'Limelight') or Hydrangea aborescens (eg. 'Annabelle' and 'Grandiflora'). In examining the virus, plants from seven different families were tested. All plants were resistant to the virus except H. macrophylla.

The virus can be spread by green aphids (Myzus persicae), through propagation, or through mechanical damage that might occur in splitting, transplanting, or pruning infected and healthy plants with the same equipment. What long term effect the virus has on plant health is unknown, but it is suspected to play a role in poor survival of H. macrophylla in some gardens.

Contributors: Nancy Rose Patrick Weicherding Bob Mugaas

Lawns

Late August is the start prime time for lawn repair. If you lost patches of your lawn from drought, August and early September are the best times to fix them. Even if you're not sure how much of your lawn is truly dead, overseeding won't hurt.

The first step it to water a day or two before you begin your rehab project so it's actively growing or not drought-stressed.

If you plant to core aerate, dethatch and over-seed: core aerate first, then fertilize if you're going to, then dethatch to break up cores, then seed. Good soil to seed contact is vital so when you're done overseeding, run a vertical mower (dethatcher/power rake) making a pass perpendicular to first pass you made earlier, when dethatching, to improve soil to seed contact. Just before giving the lawn a good drink, "rake" the area with an lawn rake with teeth inverted to firm the soil.

The end of August is a good time for the first fall fertilizer application. Apply one pound per thousand square feet with 1/3 to ½of the fertilizer in a slow release form. Then, water it in with ¼ to ½ inches of water.

For good turf health, lawns need at least ¾ inch of water per week.

Keep your mowing heights high-close to 3 inches. The last couple of mowings at end of year can be lower. Remember, the higher you cut, the greater the root mass the grass plants will have and the deeper the roots will be.

If in doubt about your soil's fertility, do a soil test now so you'll have your test results back by Labor Day.Get the form and instructions at: http://soiltest.coafes.umn.edu/submitti.htm

Phosphorus is banned from routine home lawn fertilizer. However, you may apply phosphorus if you are reseeding a thin or dead lawn. It doesn't have to be bare ground to be legal.

Trees and shrubs:
We have entered the low risk period for oak wilt. This is NOT the "no risk" period. It's ok to snip off storm-broken branches but for a standard pruning, hold off until Oct 1 or late winter. Late winter is the very best time to prune trees. Read about the best time to prune (and why!) at: http://www.extension.umn.edu/yardandgarden/YGLNews/YGLN-Dec0104.html

The oak wilt risk advisory is at:http://fr.cfans.umn.edu/extension/Home/oakwiltadvisory.html

Water your trees now because they need it now most of all. Trees are starting the slow shutdown process for winter so an inch of water per week is critical. Water stress interferes with hardening-off for winter and results in winter injury. We saw a lot of that this year! Read all about watering at:http://fr.cfans.umn.edu/extension/Home/WateringTrees.pdf

Renew mulch around woody plants. It should be two to four inches deep around woody plants and at least several feet out from the trunks of trees. The ideal is to mulch to the dripline. For young trees, the mulched area should be a minimum of three to four feet in diameter. Be sure keep 2 inches of clearance between mulch and stem. Do not pile mulch up the trunk of trees-aka "volcano mulch"; it will kill the trees.

Fertilize trees ONLY if they need it. Need is evidenced by yellow leaves, low soil fertility based on a soil test or stunted terminal growth. Mature trees should have annual shoot growth of six to eight inches. If it's less than that, fertilize, using a slow release form of nitrogen only. High nitrogen fertilizers will cause the trees to resume active growth that will not harden off by winter.

However, premature fall color in maples in clay or high pH soils does not indicate a need for fertilizer. Fertilizer is not "chicken soup" and does not help drought-stressed trees. Fertilizing will actually stress them further.

Squirrels have been damaging to tree branches, possibly in search of moisture. There have been reports of them stealing apples as well.

Fruit and flowers:

Blossom end rot. Photo credit: Beth Jarvis

Chiggers seem to be getting under a lot of people's skins this summer. A number of people have been badly bitten on legs, under socks, under arms, in the groin area--where ever skin is thinner and at hair follicles. And, they don't really burrow into the skin. They feed on skin cells. The Extension publication on chiggers is at: http://www.extension.umn.edu/distribution/housingandclothing/DK1035.html and the Yard & Garden Line News article at: http://www.extension.umn.edu/yardandgarden/YGLNews/YGLN-Aug0104.html#chiggers

Many gardeners are finding blossom end rot on their tomatoes. This is technically a calcium deficiency but the symptoms become apparent when tomatoes haven't been getting adequately watered. It is common on container-grown plants where the soil heats up quickly and water evaporates from that soil faster than it does from the ground. Fruits with blossom end rot are perfectly safe to eat. Just cut off the dried end. Bell peppers are also susceptible to blossom end rot.

Septoria has been reported on tomatoes as well. Early apples may be ripening. One test is to lift and turn the fruit. If it comes off easily, it's ripe.

Elderberries are ripening now, so net themn of you want to keep the fruit. The fall fruiting raspberries have green fruit on them. Be sure the raspberries get adequate water while fruit is forming.

Clean diseased foliage from gardens. Do not compost it. Destroy it. Corn husks, over-grown lettuce and other "clean" waste can go in the compost bin. Check cucumber and summer squash vines for maturing fruits before the fruit gets too big.

There's only about 50 days left to the frost free growing season in the TC. So, plant the last of the leaf lettuces.

Finish off dividing any irises. Place last minute spring-flowering bulb orders. They need to be planted in September-October.

Check tender roses for evidence of flower production. Mark any that haven't produced flowers for the chip pile. Grafted roses sometime send up vigorous, never-flowering shoots from the root stock. There's no point in over-wintering them.

Evaluate the performance of garden perennials and add notes to your garden journal. Plants that have failed to proper may benefit from a change of site next spring. Any new purchases/plants still in pots from the spring, should go into the ground in September.

Check garden centers for cool season annuals such as pansies and ornamental kale to add color to fall landscapes.

Editorial Notes

GarlicFest braids Photo: Beth Jarvis

Nancy Rose has agreed to pen an article on the trees of the family Fabaceae. This includes locust, honeylocust, redbud, and coffeetree. It dshould be some interesting winter reading.

For September 1, Bob Mugaas will be writing about drought lawn care/repair. I'm hoping to catch up with some more of the plant breeders at the Horticulture Research Center and report back to you. I'm still hoping to have an article on the physiological drawbacks of growing evergreens in shade vis a vis incidence of winter injury, among other things, one of theser days.

Please feel free to cut and paste any of the articles for use in your own newsletters. All we ask is that you give our authors credit.

Back issues Yard & Garden Line News are on the Yard & Garden Line home page at www.extension.umn.edu/yardandgarden/.

Deb Brown answers gardening questions on Minnesota Public Radio's (MPR) "Midmorning" program on the first Friday of every month at 10 a.m. The program is broadcast on KNOW 91.1 FM, and available state-wide on the MPR news radio stations. (Scroll down for map.)

For plant and insect questions, visit http://www.extension.umn.edu/askmg. Thousands of questions have been answered, so try the search option in the black bar at the top left of the board for the fastest answer.

If you would like to receive an e-mail reminder when the next issue of the Yard & Garden Line News is posted to the web, just send an e-mail to: listserv@lists.umn.edu (note: the second E in listserve is omitted), leave the subject line blank, then in the body of the message, type: sub yglnewslist or to unsubscribe, enter: unsub yglnewslist

Happy gardening!

Beth Jarvis
Yard & Garden Line Project Coordinator


Previous Page
University of Minnesota Extension Service Home Page
In accordance with the Americans with Disabilities Act, this material is available in alternative formats upon request.  Please contact your University of Minnesota county extension office or, outside of Minnesota, contact the Distribution Center at (612) 625-8173.

The University of Minnesota Extension Service is committed to the policy that all persons shall have equal access to its programs, facilities, and employment without regard to race, color, creed, religion, national origin, sex, age, marital status, disability, public assistance status, veteran status, or sexual orientation.