Yard & Garden Line News Volume 2 Number 19                                                              December 1, 2000

Features this issue: Low Maintenance Alternative Turf Trials    Turf ratings    Components, seeding rates, sources Gift Suggestions for Gardeners Growing Norfolk Island Pine Year-Round You Mite Have Houseplant Insects: A Pesticide Update Meal Moths or Clothes Moths? Editorial Notes

Low Maintenance Alternative Turf Trials
Mary Hockenberry Meyer and Brad Pedersen
This information was previously published in the Journal of Turfgrass Management, Vol. 3 No. 2 1999

L to R: Mowed walkway, 2" mowing height 4" height and no mow across species. Species back to front: Ram I, Sunny Lawn, Ram I, Fleur de Lawn, Azay. Photo credit: Mary Meyer

A short, dark green, weed-free lawn has been a sign of beauty and care and is often perceived as belonging to a "good citizen" in the United States. In recent years the environmental impact of such lawns has been questioned. Although numerous reports document the environmental benefits of turf, the negative effects of improper and excessive use of pesticides, fertilizer and irrigation cause concern for many homeowners and commercial grounds operators. Homeowners are often faced with societal pressure of being a good citizen and maintaining a traditional lawn, but few want to use pesticides or fertilizers beyond the minimum amounts.

Current recommendations for low maintenance turfgrasses include fine fescues, tall and sheep fescue and buffalograss. New mixtures of grasses and grass and flower mixtures are advertised as being acceptable, low maintenance alternative lawns.

The purpose of this project was to compare newer alternative lawn mixes to existing low maintenance grasses and to determine if minimal maintenance practices would result in acceptable turfgrass quality.

METHODS AND MATERIALS
The study was established at the University of Minnesota Landscape Arboretum, Chanhassen, in full sun on a loam soil, with a pH of 6.9 and low organic matter. The second location was approximately 70 miles south at the University of Minnesota Southern Research and Outreach Center, Waseca, in full sun on clay loam with a pH of 6.7 and low organic matter.

Existing cover was treated with glyphosate and tilled to prepare a uniform seedbed. One pound of nitrogen, from ammonium sulphate in a 10-10-10 fertilizer, per 1,000 sq. ft. was tilled into the soil. All material was broadcast seeded by hand in mid-August using sand as a bulk carrier, except buffalograss which was planted with plugs on 18" centers in mid-July. A light straw mulch was applied to all plots except buffalograss. Irrigation was supplied only for initial establishment during the first two weeks.

Eleven materials and two controls were planted in the summer and fall of 1994. Materials were selected based on past performance in national or regional turf trials, recommendations from seed suppliers, or new materials being marketed as low maintenance or alternative turfgrasses.

L to R: Fine fescue tends to mound when not mowed. Photo credit: Mary Meyer

Plot size was 10' x 16' with rows of six materials separated by 6' walkways. Each material was replicated three times within a randomized block. Plots were mowed as necessary to maintain 2" and 4" heights with a rotary mower that returned the clippings. Minimal mowing treatments were mowed twice a year, in late-June and again in mid-October. The three fertility treatments were: 1) 27-6-20 with 50% slow release nitrogen, applied at the rate of 1 pound of nitrogen, in early-September and again in mid-October; 2) same type and amount of fertilizer but applied in early-September only; and 3) no additional fertilizer. Mowing treatments were applied across the plots so 1/3 was cut at 2", 1/3 at 4" and 1/3 was the minimal mowing treatment. Fertility treatments were applied longitudinally on 1/3 of each plot, so every fertility treatment was applied to all heights of cut on each plot. Hand weeding was done once the following spring on the buffalograss plots; no additional weeding, pesticides, or irrigation were used.

Plots were evaluated monthly for color, cover and overall quality. Color was rated on a scale of 1 to 5: 1 being brown and 5 being dark green. Cover was rated with 1 being 100% weeds or bare ground, and 5 being only the material planted. Overall quality was rated from 1 to 3, with 1 being unacceptable, 2 acceptable sometimes or in a certain portion of the lawn and 3 happy to have it as a lawn or turf. Several Master Gardeners and Extension staff evaluated the plots on a monthly basis throughout the growing season for three years. Means were established for each plot and grand means were developed for each material at combined locations. There were no significant differences between locations and years, therefore means were combined to give three year summaries.

RESULTS AND DISCUSSION
Several materials had acceptable and not significantly different color, cover and overall ratings. The newer mixtures: Ecology Lawn Mix, Fleur de Lawn and No Mow provided good color, cover and overall ratings that were equal to the controls or traditional materials. All fescues performed well except Festuca pseudo-ovina, dwarf sheep fescue, which ranked significantly lower for color.

The warm-season grasses, Bouteloua gracilis 'Alma' and Buchloe dactyloides 378 & 455-3 did not provide acceptable cover, color, or overall ratings. Their mean scores were all 1.5 or below for overall ratings and 2.0 or less for color and cover. 'Alma' blue grama was selected due to its turf-type growth habit, however, it had major winter injury the first year of the trials. The two buffalograss selections did not compete with weeds and, by the end of the first full year, cover was less than 10%. Flowers 'n Flowers Elite, a mixtures of forbs or wildflowers, also provided little cover; final means for this material rated less than 1.5 for color, cover, or overall quality. The materials rating below 1.5 for overall quality or below 2.0 for color and cover are not listed on the attached chart.

Ecology Mix Photo credit: Mary Meyer

Sunnylawn 2", 4", and Ecology Lawn Mix 2", 4" had significantly better overall ratings than did dwarf sheep fescue at 2", 4" or minimal mowing. There was no significant difference between any other cool-season material mowed at 2" or 4". Sunnylawn minimal mowing performed significantly better in the overall ratings than did Azay sheep fescue or Discovery hard fescue in the minimal mowing treatments.

Dwarf sheep fescue, Festuca pseudo-ovina, is a shorter, fine leaved fescue, but its grey-blue color was significantly lower in the color ratings than most of the cool-season materials in this trial.

Sunnylawn, and Ecology Lawn Mix minimal mowing treatments had significantly better cover than did Azay sheep fescue and Discovery hard fescue minimal mowing treatments over the three years. Perennial ryegrass was a component of these materials, indicating an ability to provide a quick stand which would compete well with weeds.

Although occasionally visual differences were recorded in fall or early spring, no significant differences could be observed between fertility treatments. This may be due to the presence of legumes in some of the mixtures, the fact that clippings were left, and the amount of available nutrients originally in the soil. A long-term study would probably show differences in fertility levels, especially when compared to no additional nutrient donation.

A brief drought occurred during late summer of 1996, however it was not substantial enough to affect these trials. Precipitation levels were near normal and adequate for acceptable turf, without supplemental irrigation. Winter weather conditions during 1996-97 damaged a significant amount of turf in Minnesota, however, perennial ryegrass which has shown winter injury in USDA Zone 4, did not experience any apparent winter injury in these trials.

Ecology Lawn Mix and Fleur de Lawn both contained clover, Trifolium spp., and yarrow, Achillea millifolium. Evaluators in this study found these to be acceptable in the overall quality ratings. For homeowners, personal preference may define these plants as weeds, however commercial operators probably would not object to these components in a low maintenance area.

Yarrow in Ecology Mix. Photo credit: Mary Meyer

1. New mixtures of cool-season grasses and forbs provided acceptable turf, equal to the traditional cool-season grasses.

2. Warm-season grasses and flower mixtures were significantly worse when ranked for color, cover and overall ratings than cool-season grasses.

3. Fine fescues, Ecology Lawn Mix, and Fleur de Lawn provided dark green color equal to or better than the controls: Ram I Kentucky bluegrass, and Sunnylawn mix.

4. Perennial ryegrass was a component of the most acceptable minimal mowing treatments. It established quickly and competed well with weeds and tolerated minimal mowing. However, long-term trials of perennial ryegrass in northern climates often show decline due to cold temperatures.

5. The 4" cutting height rated as acceptable as the 2" height of cut.

Homeowners and commercial turf managers looking for low maintenance cool-season materials should choose traditional mixtures of Kentucky bluegrass, perennial ryegrass and red fescue; a mixture of fine fescues; or the new mixtures of perennial ryegrass and forbs. Minimum maintenance practices, such as higher mowing or mowing only twice a year were found to be acceptable. Acceptable turf with no use of herbicides was possible due to the rapid establishment of plots with perennial ryegrass and favorable environmental conditions.

Turf Name	Mean overall rating for 95, 96, & 97
Sunnylawn - 4"	2.7691 a*
Sunnylawn - 2"	2.7670 a
Ecology mix - 4"	2.7387 a
Ecology mix - 2"	2.7146 a
Fleur de lawn - 4"	2.6699 a,b
Fleur de lawn - 2"	2.6393 a,b
Ram-I - 2"	2.6075 a,b
Fine fescue - 4"	2.5991 a,b
Fine fescue - 2"	2.5968 a,b
Ram-I - 4"	2.5657 a,b
Azay sheep - 2"	2.4263 a,b,c
No mow - 4"	2.4037 a,b,c,d
Discovery - 2"	2.3860 a,b,c,d,e
Discovery - 4"	2.3746 a,b,c,d,e
No mow - 2"	2.3612 a,b,c,d,e
Azay sheep - 4"	2.3590 a,b,c,d,e
Sunnylawn - minimal mowing	2.2788 a,b,c,d,e,f
No mow - minimal mowing	2.1395 b,c,d,e,f,g
Dwarf sheep - 4"	2.0240 c,d,e,f,g
Dwarf sheep - 2"	2.0004 c,d,e,f,g
Ecology mix - minimal mowing	1.9854 c,d,e,f,g
Fleur de lawn - minimal mowing	1.9381 c,d,e,f,g
Fine fescue - minimal mowing	1.8844 d,e,f,g
Dwarf sheep - minimal mowing	1.8504 e,f,g
Ram-I - minimal mowing	1.7683 f,g
Azay sheep - minimal mowing	1.7413 g
Discovery - minimal mowing	1.6657 g
* means followed by different letters are significantly different at the P = .05 level using Tukey HSD.

Plant materials, sources and seeding rates for low maintenance turfgrass trials, University of Minnesota, 1995-1997.

Botanical Name/components	Common or Trade Name	Seeding rate	Source
Festuca ovina 'Azay'	sheep fescue	3.5 lbs/1,000 sq. ft.	Pickseed West, Inc., Box 888 Tangent, OR 97389*
Festuca pseudo-ovina	dwarf sheep fescue	3 lbs./1,000 sq. ft.	Pickseed West, Inc., Box 888 Tangent, OR 97389*
Festuca longifolia 'Discovery'	hard fescue	3.5 lbs/1,000 sq. ft.	Turf-Seed, Inc., PO Box 250 Hubbard, OR 97032*
33% Festuca ovina; 33% F. longifolia; 16.5% F. rubra 'Marker'; 16.5% F. rubra 'Longfellow'	fine fescue mixture	3.5 lbs/1,000 sq. ft.	Twin City Seed, 7263 Washington Ave. S. Edina, MN 55439*
Buchloe dactyloides	buffalograss, 378 & 45-3	3" plugs, 18" spacing	University of Nebraska, *
Bouteloua gracilis 'Alma'	blue grama	3" plugs, 18" spacing	USDA, NRCS, 1036 Miller St. SW, Los Lunas, NM 87031*
25% SR100 chewings fescue; 25% sheep fescue; 12.5% Dawson red fescue; 12.5% SR3100 hard fescue; 12.5% Scaldis hard fescue; 12.5% creeping red fescue.	No Mow	5 lbs/1,000 sq. ft.	Prairie Nursery, PO Box 306, Westfield, WI 53964*
77.28% Lolium perenne 'Elka'; 16% flowers, (such as Achillea millifolium); 3.9% salina strawberry clover.	Fleur de lawn	1 lb/1,000 sq. ft.	Hobbs and Hopkins, Ltd., 1712 SE Ankeny, Portland, OR 97214*
67.57% Lolium perenne; 30.62% Festuca rubra; also includes a 3 oz packet of "strawberry and dutch white clover, wild English daisies, roman Chamomile, yarrow and baby blue eyes".	Ecology Lawn Mix	2 lbs/1,000 sq. ft.	Nichols Garden Nursery, 1190 N. Pacific Hwy. Albany, Oregon 97321-4580*
66% annual and 33% perennial flowers: Centurea, Clarkia, Coreopsis, Silene, Eschscholzia, Linum, Dianthus, etc.	Flowers 'n Flowers Elite	1.4 lbs/1,000 sq. ft.	Pickseed West, Inc. Box 888 Tangent, OR 97389*
30% Lolium perenne 'Omega II'; 25% Poa pratensis 'Park', 25% 'Monopoly'; 20% Festuca rubra.	Sunnylawn Mixture; CONTROL	3.5 lbs/1,000 sq. ft.	Peterson's Seed Co., 7800 Rt. 101, Shakopee, MN 55379*
Poa pratensis 'Ram I'	Ram I Kentucky bluegrass; CONTROL	2 lbs/1,000 sq. ft.	Peterson's Seed Co., 7800 Rt. 101, Shakopee, MN 55379*

* Donated seed for this research project


Gift Suggestions for Gardeners
Deborah Brown, Extension Horticulturist

MN Landscape Arboretum Conservatory. Photo credit: U of MN Extension Service

Chanukah and Christmas are only a few days apart this year. How about some easy, inexpensive gift ideas for folks who enjoy plants and gardening? You should be able to find something for just about everyone on your list without having to break the bank.

Some of these gifts make great stocking stuffers. Others would be perfect presents for a favorite teacher or co-worker. They might serve as a host or hostess gift or a token of friendship for a special neighbor.

* Paperwhite narcissus: These bulbs don't need to be forced; they'll bloom indoors three or four weeks after you plant them, with no special chilling treatment. Each will produce one or two flower stems with clusters of pungently scented, dainty white blossoms. You can buy them in kits complete with shallow bowls and gravel, but they're also available individually at many garden centers, under a dollar a piece.

* Amaryllis bulbs run five or six dollars and up, but given good growing conditions they'll bloom repeatedly for years to come. The bulbs send up one or two giant stalks, usually with four enormous red, white, or pink lily-like flowers on each. Many garden centers also have a selection of more unusual species and cultivars of amaryllis. Bulbs are available individually, pre-potted, or in a kits with soil and a container.

* Blooming plants, even small ones, are always a welcome gift. African violets, brilliantly colored kalanchoes and Christmas cactus, tiny azaleas and mini-mums all add a festive touch at a very reasonable price. With care, the violets and cactus will bloom again and again. (Make sure you whisk live plants quickly from the store to a heated vehicle, even if they're double wrapped; they're very sensitive to cold temperatures.)

* Floral preservative will be appreciated by any gardener who brings flowers indoors for bouquets. The makers of Schultz Instant houseplant fertilizer offer a product called "Schultz Instant Cut Flower Food." A few drops in a vase of water helps cut flowers last longer, just like the little enclosures of dry preservative you get when you buy flowers from a florist or grocery.

Sunken garden at Como Park Conservatory. Photo credit: U of MN Extension Service

* Seed packets are available at garden centers year-round, not just in spring. You'll find seeds for ornamental grasses, wildflowers, houseplants, and gourmet herbs and vegetables, along with lots of traditional flowers and vegetables.

* Garden Magazines: There's a large choice of beautifully illustrated Garden magazines at bookstores such as Barnes and Noble as well as at many garden centers. Individual copies run about three dollars and up. Look for Northern Gardener, American Horticulturist, Fine Gardening, Garden Gate, Horticulture, and others.

* 2001 Calendars: Dozens of calendars feature lovely flowers and gardens. Our favorite, of course, is Minnesota Gardening, published by the University of Minnesota Extension Service and Experiment Station. It has great photos along with tips and advice specially formulated for gardening in our climate. You'll find it in book and gift stores and county extension offices. You can also order it directly from the University of Minnesota at 612-624-4900 in the metro area or 1-800-876-8636 outside the metro.

* Garden tools make particularly practical gifts. Useful, but inexpensive choices include trowels and other hand tools, thick garden gloves, and kneeling pads made of dense foam to cushion weary knees.

Don't forget, when all is said and done, the gift of time is often the most treasured gift you can give. Why not invite a friend or special relative -- perhaps someone who doesn't get out much on their own -- to visit the Minnesota Landscape Arboretum in Chanhassen or Como Conservatory in St. Paul?

Growing Norfolk Island Pine Year-Round
Deborah Brown, Extension Horticulturist

Daffodil bouquet with Norfolk Island Pine in background. Photo credit: Deb Brown

Many people buy small Norfolk Island Pines trimmed with ribbon and miniature red ornaments for Christmas. Despite the fact that these plants begin their lives as petite houseplants, they are capable of tremendous growth; we get a call or two every year from someone whose plant has grown so successfully it's nudging the ceiling!

It seems, then, that Norfolk Island Pines can't be too difficult to grow -- particularly if you can provide a compatible environment. But don't count them among the easiest houseplants you could grow indoors, either. They need just the right balance of bright light and cool temperatures in order to thrive.

So what's the best way to insure long term success with these plants? To get a good feel for what a plant needs to thrive indoors, it's always a good idea to check how and where it grows in its native

Growing Outdoors

Despite their name, Norfolk Island Pines are not really pines. Though they're used in the outdoor landscape in southern Florida and California, they are not native to North America. Instead, they belong to the Araucaria family, a group of tropical and sub-tropical "primitive" conifers that are indigenous to the southern hemisphere.

In their native environment, exposed to lots of sunlight and abundant moisture much of the year, these trees can reach enormous heights, growing well over two-hundred feet tall. And though they possess little or no frost tolerance, they can tolerate cool temperatures -- the kind we often have indoors in winter -- with ease.

Growing Indoors; Light

As you might expect, Norfolk Island Pines grow best in a bright, sunny location indoors. Too intense sunlight can lead to a faded yellow-green appearance, however, so pull them back a foot or two from south or west windows in summer when light is strongest and most plentiful.

These plants can adapt to survive many years of lower light, but inevitably their form will suffer under less than optimal conditions. Plants will stretch and become more spindly; their older branches will take on an unattractive droopy appearance, and there will be more stem space between one year's whorl of new branches and the next.

(Norfolk Island Pines typically put out one whorl or tier of new branches annually. If you're not careful to rotate the plant regularly, it will lose its symmetry and grow towards the light.)

Norfolk Island Pine Photo credit: Deb Brown

Temperature, Moisture, and Humidity

Two of the most common problems these plants face indoors are browning needles and dropping lower branches. Usually they can be attributed to hot dry air, low humidity, or allowing the soil to dry excessively before watering. Too much fertilizer can also contribute to needle drop and branch loss.

This time of year, ideal night temperatures for Norfolk Island Pines range from fifty to sixty degrees, with daytime temps only about five degrees warmer. Spring and summer temperatures may be higher, because there's plenty of light to support more active growth at that time.

While you CAN lower your thermostat, it's practically impossible to regulate indoor humidity in a way that provides an ideal environment for Norfolk Island Pines yet is not too humid for people and household furnishings. But you can compensate for this lack of humidity by watering the plants carefully and conscientiously.

Keep the soil relatively moist, but not saturated, most of the year. Water the plant thoroughly, but spill out or siphon off any excess moisture left in the container's tray after a few minutes. Check the soil every few days, and water thoroughly again once the surface feels dry. In winter, when temperatures are usually cooler indoors and there are fewer hours of natural daylight, allow the soil to become a bit drier -- but never bone dry -- before you water it.

Soil and Nutrients

Because Norfolk Island Pines are rather slow growing, they need repotting only every three to five years. Use fresh potting soil that drains well, yet contains a reasonable amount of organic matter in the form of peat moss, and choose a pot that's not too much larger than the old one. Keeping the plant's root system a bit confined may help maintain the tree at a smaller and more manageable size for a longer time.

During spring, summer, and early autumn, fertilize Norfolk Island Pines with a dilute houseplant fertilizer every few weeks. Use a product meant specially for acid-loving plants, mixed half- strength. There's no need to fertilize new plants, purchased for the holidays, until late February or early March.

And what can you do if your Norfolk Island Pine hits the ceiling? There are only two choices; give the plant away -- or move to a house with higher ceilings! You really can't prune a Norfolk Island Pine without deforming it permanently.

You Mite Have Houseplant Insects: A Pesticide Update
John F. Kyhl, Entomology Technician

Mealybugs on jade plant. Photo credit: Jeff Hahn

Outdoor gardens are now "in bed"under a blanket of snow. Gardeners now have time to pay more attention to their houseplants Upon closer inspection, they may find insects on their plants.

Many non-chemical management techniques are available to control houseplant insects. When insects are found, wash the plant off in the sink or shower, dab individual insects with alcohol-moistened cotton swabs, pick them off with tweezers or fingers, or prune off infested regions. When these techniques do not work, you can use a variety of insecticides. Be sure to read the label before purchasing any product to be sure it is not toxic to your house plant

The following is a list of some of the products available for use:

Ortho’s Houseplant and Garden Insect Killer contains the active ingredient bifenthrin. This product is sold as a pump spray, has a residual period of about 2 weeks, and kills a variety of insects, such as aphids, mealybugs, thrips, scales, and whiteflies. It is also very effective against spider mites.

Bonide now sells Eight Garden and Home Insect Control, which contains permethrin as an active ingredient. Permethrin also comes as a pump spray, has a 2 week residual period, and controls aphids, whiteflies, and scales.

Bonide also sells the systemic insecticide Di-Syston with the active ingredient disulfoton. It is sold as granules that are watered into the soil, and has a 6–8 week residual period. Use this product ONLY IF the plant it is actively growing and is NOT a food plant, such as indoor herbs. Disfulfoton may be absorbed through the skin so be careful when handling treated soil and keep children and pets away from the soil. Disulfoton works well on scales, aphids, and mealybugs.

Resmethrin/tetramethrin/pyrethrin products are available from a variety of manufacturers and have a variety of trade names. These products come in pump sprayers and aerosols. They have a short residual period, so you will generally need to repeat applications as directed on the label. They differ slightly in what insects they control best, but all should have some effect on scale, mealybug, whiteflies, aphids, and thrips.

Insecticidal soaps and horticultural oils have wide uses in controlling houseplant insects. These products are available from many manufacturers and have many trade names. Soaps can kill spider mites, aphids, whiteflies, mealybugs, and scales on contact and should be reapplied. Oils smother their target insects and are commonly used against aphids, mealybugs, spider mites, thrips, scales, and whiteflies.

Finally, Bacillus thuringiensis H-14 (Knock-out Gnats) is available to control fungus gnats. This product is available at least through Gardens Alive, a mail order company. It targets only fungus gnat larvae and has no effect on other houseplant pests or fungus gnat adults.

Good coverage is critical when spraying insecticides to control houseplant insects . Turn the plant pot on its side and then spray, then turn as needed to reach the unsprayed foliage. This method allows more thorough insecticide coverage, especially to the undersides of the leaves where insects generally hide. Finally, disposing of a highly infested plant is one of the best houseplant insect management techniques available, because there are cases in which chemicals cannot save an infested plant.

(Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the University of Minnesota Extension Service is implied.)

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

Meal Moths or Clothes Moths?
Bruce Giebink, Entomology Technician

Indianmeal moth adult. Photo credit: Kansas Dept. of Ag.

During the past month the Yard & Garden Clinic has received a fair number of calls about and samples of small moths found flying around inside homes. These moths may occur throughout the house, but most people report seeing them either in their kitchen or in their bedroom. Based on these observations, the suspects could either be Indianmeal moths (IMM) or clothes moths. Over 95% of the small moth specimens that we have received at the clinic turn out to be Indianmeal moths. So how do you determine which one is infesting your home? If you tend to find them in or near the kitchen, typically during the daytime, most likely you have Indianmeal moths. But if you see them in or around your bedroom closets or storage rooms, usually at night, it’s possible you could have clothes moths.

We can usually identify Indianmeal moths quickly by looking closely at the front wings. The base of the front wing is pale gray or tan and the outer two-thirds is reddish-brown with a “coppery” luster. However, you need to be careful because it is common for the scales to be rubbed off on IMM, so it appears that the wings are one color. Clothes moths are a uniform buff/golden color, have a fluttery flight, and tend to avoid light. Because clothes moths are not common, have any specimens identified if you think they are damaging fabrics.

Indianmeal moths Plodia interpunctella (Hbn.) – These are the most common moths infesting homes. First, only the larval stage feeds. Larvae are off-white with shades of yellow, pink, green or brown and grow to ½ inch. Adults lack functional mouthparts and are unable to feed; their role is to mate, lay eggs, and keep the infestation going. Indianmeal moth larvae feed on a wide variety of grain and grain products, dried fruits, seeds, graham crackers, nuts, powdered milk, chocolate, etc. Quite often home infestations get started in dried pet foods or birdseed and then spread to other stored products. Infested foods will have silk webbing present on the surface of the product. When they mature, larvae may wander long distances before spinning a cocoon. Quite often homeowners will report seeing both caterpillars and cocoons on ceilings and walls.

Controlling IMM infestations – Sanitation is the key to eliminating existing IMM infestations. Sanitation combined with storing food in sealed containers will prevent future infestations. First, inspect all potentially susceptible food to see if it’s infested. If it is, most likely you’ll see webbing on the surface of the food. Or you may see cocoons either on the package or inside the cupboard. When you discover infested products, wrap it in plastic and discard it. You can save bird seed or pet food (or lightly infested food products), by freezing them at 0º F for at least four days. You should automatically freeze unopened food packages older than 60 days, even if you didn’t see any insects.

Larva on dried fruit.

Adult at rest. Photos copyrighted by:  Jack DeAngelis, Oregon State U

Food Storage – Store susceptible, insect-free food in containers with tight lids, such as glass jars or heavy plastic containers. Storing products in the refrigerator is another option, especially for items you use infrequently.

Sanitation – The key is to deprive any stored product pest of even the tiniest amount of food. Do this by thoroughly vacuuming your cupboards to remove crumbs or spilled food from cracks and corners. Also check spice drawers, toasters, cupboards and other places where crumbs accumulate. Disinfecting counters and other places does NOT affect these insects.

Insecticides are not practical or necessary. You can't spray insects in food without contaminating the product. Spraying insects found out in the open will not do any good either, particularly if you haven’t located and eliminated their food source. The key to eliminating the problem is to:
*Locate and discard ALL infested food
*Store uninfested food in glass jars or heavy plastic containers with tight-fitting lids.

But, what if you’ve done all these things and you still see some moths around? Were all your efforts in vain? Probably not. These moths are simply those individuals that emerged from pupae located away from the primary food source (i.e., infested containers). Although you may see them for another four to five weeks, they pose no threat IF their larvae have nothing to feed on.

Clothes Moths – Although clothes moths infestations are much less common then they used to be, if you notice small “fluttery” moths, usually during the evening hours and around closets, it’s possible you have an infestation of clothes moths. Particularly if you happen to be a "pack rat" and have a closet full of off-season, off-size and off-fashion wool clothes (or any clothes containing natural animal fibers). In any case, what we are talking about are natural fiber clothes items that are usually stored for extended periods because they are only worn seasonally, occasionally, or are still too good to part with yet.

Clothing moth.. Photo credit: Clemson Univ.

Webbing clothes moth, Tineola biselliella (Hummel) and casemaking clothes moth Tinea pellionella (Linnaeus) – Although both species exist in Minnesota, the webbing clothes moth is by far the most common. Clothes moth larvae will feed on any clothing containing natural animal fibers, particularly woolens and furs. They’ve also been reported to feed on leather, carpets, upholstered furniture, felts in pianos, wool wall hangings, feathered hats, antique dolls and toys, parts of heating units, water pipe and duct insulation, wool brushes, lint, dust and pet hairs behind baseboards and in flooring cracks. They are especially damaging to fabric stained with beverages, urine, oil from hair and sweat.

Small, white larvae damage clothing items as they feed on natural fibers in the material. A closer look usually reveals silken cases, line of silken threads and fecal pellets over the surface of the materials. The adult moths do not feed and are completely harmless. Note: Just because you have a hole in a piece of clothing doesn’t mean you should suspect clothes moths. There are many other possible explanations for the holes, particularly if (1) the clothing does NOT contain any natural animal fibers or (2) if the item has NOT been stored for a long time.

Preventing Damage – To prevent an infestation of clothes moths (and carpet beetles, another fabric pest), housekeeping is important. Removing dust and lint will eliminate breeding and egg laying sites, particularly on rugs, on carpets next to walls and under furniture and around registers and ducts, baseboards, etc.

Clothes Storage – Inspect clothing and storage areas in the spring for potential infestations. Dry clean or launder all clothing before storing (as soiled clothes are more attractive). Store clothing in tight boxes or chests (we suggest NOT using plastic bags). Along with the clothing, place mothballs or crystals (naphthalene) or part of a no-pest strip. Despite their reputation, cedar chips, cedar chests and cedar closets are overrated as a control of wool pests. Even high concentrations of cedar oil (e.g., fresh lumber and lumber recently treated with cedar oil) only kill young larvae; older larvae and adults are unaffected.

A less “smelly” alternative to mothballs is formulation of lavandin oil, which repels clothes. An example of a product that contains lavandin oil is OFF! Moth Proofer, which is marketed by the SC Johnson Company. This product will protect items from clothes moths for a single storage season. In addition to eliminating the mothball smell, OFF! Moth Proofer also eliminates the risk of accidental poisoning (either by inhalation of ingestion) by naphthalene or para-dichloro benzene (PDB).

Finally, get rid of or properly store remnants or scraps of wool, fur, fleece and other similar material (i.e., anything composed of natural animal fibers containing keratin).

Controlling an infestation – If you already have an infestation, vacuum or brush the insects off the article, then wash, dry clean, freeze, or heat it. Freezing, however, only works if you’re able to shock the pests; that is, quickly moving the infested materials from room temperature (about 70º F) to near zero and then keeping them there for at least 4 days. Heating articles to above 130º F for about an hour will also kill any eggs of larvae.

Finally, if you feel you need to resort to using insecticides be sure NOT to treat clothing because they can stain and damage garments. Treat all cracks and crevices (along baseboards, etc.) with a residual insecticide. But be sure to clean and dust all rugs, rug pads and carpets first. If you’ve done all these things and the problem persists, we suggest you contact a licensed pest control operator (PCO). Also call a PCO if you feel you need to treat infested stuffed furniture and other salvageable commodities. Before using insecticides, always read the label directions and follow safety precautions.

Editorial Notes

Pitcher plant. Photo credit: Beth Jarvis

Chatted with Dean Hertfeld, the state pesticide applicator training coordinator, the other day. We'll be publishing an article, just in time for crabgrass treatment, on what you should know before hiring someone to spritz your weeds.

Dr. Colleen Cannon, Extension's new structual and stored grain pest expert, has agreed to share some fascinating facts about carpenter ants soon.

So I'm adding those to the list of upcoming articles that includes:
*An update on the apple bagging project, a non-chemical apple production method for homeowners.
*Soluble salts on soil tests--what does it 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 have gardening questions, please call the Yard & Garden Line at (612) 624-4771.

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

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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