Yard & Garden Line News Volume 2 Number 16                                                              September 15, 2000

Features this issue: Storing Home Grown Produce Black and Yellow Argiope Spider Late Summer Caterpillars Millipedes Editorial Notes

Storing Home Grown Produce
Deborah Brown, Extension Horticulturist

Red potatoes. Photo credit: Cindy Tong

Many of us like to store home grown produce such as apples, roots crops, and squash in the basement over winter. Actually, we often lay aside some of this fall's harvest for later use, regardless of whether we grew it in our own gardens or bought it fresh at a local orchard or farmers' market. Somehow it just seems to taste better than produce that's been trucked in from California or Florida.

Unfortunately, most finished basements may be too warm and dry to store produce very long, and most garages get way too cold --at least when outdoor temps drop into the single digits. An old refrigerator, however, can be a perfectly good substitute "root cellar." You can keep its contents cool without freezing or fluctuating temperatures, and unless it is self-defrosting, produce will not dry excessively.

It's always a good idea to put humidity-loving produce in plastic bags with some holes punched through to provide a bit of air circulation; it's absolutely necessary when you store produce in a self-defrosting refrigerator.

Store fruits and vegetables separately if you can. Keep only high quality, unblemished specimens; cuts and bruises allow disease organisms to enter and moisture to exit. If some of your produce is less than first quality, make a point of using it up as soon as possible.

Storage Tips:

Pumpkins. Photo credit: AAS

APPLES: Apples keep best between 30 and 32 degrees, with high humidity. They'll mature twice as fast at 40 degrees. Minnesota favorites, such as Honeycrisp, Haralson, Regent, Fireside and Keepsake will last through March provided they're kept cool. A favorite pie apple, Northwestern Greening, will be damaged when stored below 36 degrees, but you still want to keep it as close to that temperature as possible, rather than much warmer.

POTATOES: Store potatoes as close to 40 degrees as you can. Warmer temps cause early sprouting; cooler temps mean an objectionable sweet flavor. (You can eliminate the sweetness by storing potatoes at room temperature for several days before cooking them.) Keep potatoes in total darkness. Light exposure to "greens" them up. Remove all green parts before cooking; they're bitter tasting and mildly toxic.

WINTER SQUASH: The key to storing winter squash is keeping only fully mature fruit, first "curing" them in a warm room for about ten days to toughen their skin. Then store them under dry conditions between 50 and 55 degrees. Check every few weeks for mold, and discard any that have deteriorated. Wipe the healthy ones with a soft cloth you've dipped lightly in vegetable oil. Winter squash should last anywhere from three to six months.

Black and Yellow Argiope Spider
Jeffrey Hahn, Assistant Extension Entomologist

Black and Yellow Argiope Spider. Photo credit: Ken Gray Collection

Big black and yellow spiders in the center of webs have been commonly observed late this summer. These spiders belong to the family called orb weavers (Araneidae). A common species in this group is the black and yellow argiope (ar-JYE-o-pee) spider, Argiope aurantia. Also known as garden spider, this arachnid has a body length up to 1 inch long. Including the legs, it can be over several inches long. This is a strikingly colored spider with a black body and yellow markings on its abdomen. To some people, the markings resembles flames. This spider is often found building its web in gardens or in tall grass.

Because of its size, some people assume that a black and yellow argiope spider is dangerous to people. In reality, it is a shy spider (as nearly all spiders are). It stays in its web and could only move slowly on the ground if it fell out of it. It has poor vision, even for a spider. It would be very unlikely to bite people. If this spider did accidently bite someone, the injury would not be worse then a bee sting. This spider is not dangerous to people and should be left alone.

Late Summer Caterpillars
Jeffrey Hahn, Assistant Extension Entomologist

Cecropia caterpillar.

Fall webworms webbing branch Photos: Jeff Hahn

Yellownecked caterpillar.

Redhumped caterpillar. Photos: Dept. of Entomology

Morning glory prominent. Photo credit: Doug Holen

Hag moth caterpillar. Photo credit: Jeff Hahn

Unknown slug caterpillar. Photo credit: Leroy Williams

Many caterpillars are active in August and September on trees and shrubs. In some cases, people are concerned that their feeding may injure woody plants. In other cases, they are just curious as to the identity of the insects, especially when it is colorful and/or unusual looking. Fortunately, caterpillar feeding this late in the season has little, if any, impact on tree health. Treatment is rarely necessary.

The following is a brief description of some caterpillars that may be seen at this time.

Cecropia caterpillar is in the family of giant silk moths (Saturniidae). It grows up to 4 inches long. It is light green with a double row of reddish orange knobs behind the head and yellowish knobs down the rest of its back. There are also blue knobs on the side of it body. Cecropia feeds on the leaves of many hardwood trees, including linden, maple, cherry, boxelder, elm, birch, willow, hawthorn, and poplar.

Fall webworm is in the family of tiger moths (Arctiidae). It grows to about 1 inch. It is yellowish or greenish with long, fine white hairs with two rows of black spots down its back. It feeds in nonsocial groups, producing a silken webbing that covers the ends of branches. It feeds on black walnut, ash, crab apple, elm, maple and many other deciduous trees and shrubs.

Yellownecked caterpillar is in the family of prominents (Notodontidae). It grows to be about 2 inches long. It has a black head and a black body with yellowish stripes and a yellowish rectangle behind its head. Yellownecked caterpillars feed on many deciduous trees, including birch, oak, elm, maple, walnut, mountain ash, and linden.

Redhumped caterpillar is in the family of prominents (Notodontidae). It grow to be about 1 inch long. It has a red head and a wavy black, yellow, and white striped body with a red projection (hump) on the thorax behind the head. Redhumped caterpillars feed in nonsocial groups on many deciduous trees including maple, oak, willow, poplar, and apple.

Morning glory prominent is in the family of prominents (Notodontidae). It is very closely related to the unicorn caterpillar. Both grow to be about 1 inch long. They have various shades of brown throughout its body except for a strikingly colored green area behind its head. They also have a conspicuous dorsal horn right behind the green area. They feed on many deciduous trees and shrubs, including apple, elm, quaking aspen, hickory, birch, and willow.

Whitemarked tussock moth is in the family of tussock moths (Lymantriidae). It grows to be about 1 to 1 ½ inches long. It has a red head and a blue-gray, cream, and black striped body. It is very hairy with a pair of long black tufts in the front by the head and one black tuft on the tail. There are also four cream colored toothbrush-like bristles on the top of the body behind the head. Whitemarked tussock moth feeds on many deciduous trees and shrubs, including linden, apple, birch, elm, and poplar.

Slug caterpillars (Family Limacodidae). This is a very odd-looking group of caterpillars. It is difficult to believe that they eventually turn into moths. The hag moth (sometimes called monkey slug) grows to be about 1 inch long. It is brown with three long and short pairs of lobes (sometimes these lobes are missing). It is densely covered with spines that can be irritating to the touch. Hag moths feed on cherry, oak, and other trees and shrubs. Some slug caterpillars are, as the name implies, slug-like and smoothed skinned.

For anyone with a special interest in caterpillars, there are many references that describe and illustrate them. One in particular is the U.S. Forest Service publication Caterpillars of Eastern Forests authored by David Wagner, Valerie Giles, Richard C. Reardon, and Michael L. McManus (FHTET-96-34, November 1997). It has many excellent descriptions and color pictures. It is also available on the internet at: http://www.npwrc.usgs.gov/resource/2000/cateast/cateast.htm

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

Millipedes
Jeffrey Hahn, Assistant Extension Entomologist

Millipede. Photo credit: Dept. of Entomology

What's one inch long, looks like a dark-colored worm and curls up when it dies? That is a typical description of an insect relative known as a millipede. Although millipedes ar related to insects because they both have an exoskeleton and jointed appendages, one way they differ is the number of legs they have. Insects have six legs while millipedes possess anywhere from 28 to 40 very short legs (in fact some people don't even notice the legs). Millipedes prefer damp, cool areas and are often found under leaves, stones, loose bark, brush piles, and in other protected places. They feed on decaying plant material.

It is common for millipedes to enter buildings during late summer and fall as temperatures start to cool. They find their way through cracks in foundations, gaps around windows and doors, and other small spaces at ground level. These insect relatives are particularly common during wet, rainy weather. Fortunately millipedes are harmless to people and our property. They do not reproduce indoors and usually die soon after coming inside because the air is too dry. Nevertheless, millipedes are often viewed as a nuisance, especially when large numbers are present.

To control millipedes, first try to prevent them from getting indoors. Repair or seal cracks in the foundation, spaces around windows, doors, and other places where millipedes may enter. Also remove potential millipede hiding places by raking up leaves, removing stones, mulch, bricks, firewood and other vegetation or objects close to your home. This gives millipedes fewer hiding places and less opportunity to get inside. If large numbers of millipedes still find their way into your home, you can supplement your nonchemical efforts with a temporary insecticide barrier. Spray outside around the foundation and ground with a product containing permethrin, bifenthrin, or diazinon.

Once millipedes are inside, just remove them with a vacuum or a broom. If live millipedes persist, look for a area that remains damp that allows them to survive. Reducing the humidity with a fan or dehumidifier should result in their death. Insecticides are not suggested for indoor use. They are unnecessary because they do not prevent millipedes from entering your home and when they do get into your home, they die soon on their own anyway.

Millipedes are a temporary problem. Once freezing weather arrives, millipedes go away on their own.

Editorial Notes

Red maple at Arb. Photo credit: Beth Jarvis

Fall appears to be coming, whether we're ready for it or not. In a month, gardens may be dead due to a hard frost. Northern Minnesota always comes in first in that competition; I believe some town had already reported killing frost overnight temps. We can pack away our gardening stuff for another year.

While tomatoes will soon be history, there's still plenty of time for fall lawn care. Oct. 1, Jon Powell, turf pathologist, will return discuss fall and lawn diseases.

Oct.1 also marks the beginning of our monthly publication schedule. We will publish monthly thru March.

In future issues:
*A shoreline restoration project
*An update on the apple bagging project, a non-chemical apple production method for homeowners.
*Soluble salts on soil tests--what's mean?
*Growing grapes in Mn.
*Conservation biocontrol--what is it?
*Does treated lumber leach arsenic?

I rely on your comments and questions for ideas for future articles. Please, keep the story ideas coming! We really try to be responsive to your needs.

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/. Our home page has clickable links to most of the components of the Yard & Garden Line, such as Bell Museum of Natural History, INFO U and the Soil Testing Lab.

Deb Brown answers gardening questions on Minnesota Public Radio's (MPR) "Midmorning" program on the first Thursday of every month at 10 a.m. Katherine Lanpher hosts the program that is broadcast on KNOW 91.1 FM, and available state-wide on the MPR news radio stations.

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
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Happy gardening!

Beth Jarvis
Yard & Garden Line Project Coordinator

Websites
Sustainable Urban Landscape Information Series. This site contains everything from landscape design planning and lawncare to both herbaceous and woody plant selection databases. The URL is:http://www.sustland.umn.edu


For pesticide info, for both home owner and professionals, check out:

http://www.crc.agri.umn.edu/~mnhelps/

There's also some very interesting reading at Forest Products website. To get there from here, click on: http://www.cnr.umn.edu/FR/extension/
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