Yard & Garden Line News Volume 7 Number 16                                                               October 1, 2005

Features this issue: How To Kill A Tree: Herbicide Advice for Homeowners Brown Recluse Review and Update October Garden Calendar Editorial Notes

How To Kill A Tree: Herbicide Advice for Homeowners
Patrick Weicherding, Regional Extension Educator, Forestry

Woody plants that are "undesirable" in natural areas of public lands also occur on private property. These may have been planted intentionally or introduced as seeds from other areas by birds and wildlife or they may have spread vegetatively across property lines. Some of these plants are described as being "invasive" and when they are growing on private property can serve as a source of infestation to nearby natural areas. Generally, homeowners are encouraged to remove invasive plant species (local ordinances sometimes require their removal) but sometimes they simply want to get rid of trees or shrubs that have outgrown their usefulness.

Control methods that can be used by homeowners are similar to those used in natural resource management by professional land managers. However, the scale of the control effort can be very different, ranging from the removal of a single tree to removal of several acres of woody species. Homeowners with several acres of undesirable plants, especially invasive plants, may use similar methods and herbicides as professional land managers, while those with small areas or a small number of trees can use simpler methods. The principle difference in herbicides used by professional land managers is packaging, where products can be purchased in concentrated form in large quantities. Usually, a pesticide applicator's license is required to purchase and use these products.

This article discusses methods and herbicides that can be readily used by homeowners for removal of undesirable species, and is intended for general information only. Directions for use on the manufacturer's label of specific herbicides must be followed. Also note that many cities and counties have tree preservation ordinances that prohibit the random destruction of trees and shrubs. Always check with your local government officials to determine if a permit or permission is required before removing unwanted trees.

Herbicides

Herbicide products can be purchased in many different forms depending for the most part on how they will be applied. Generally, they contain an active ingredient, a diluent (to dilute the product), and sometimes other additives that enhance the performance of the herbicide (such as surfactants). The active ingredient may be either oil soluble (diluted in oil) or water soluble (diluted in water). Active ingredients contained in the majority of herbicide products used by professional land managers are triclopyr amine (water soluble), triclopyr ester (oil soluble), glyphosate (water soluble), and imazapyr (water and oil soluble) (see Table 1). Herbicide products that contain imazapyr are not recommended for use in home landscapes because of the potential for imazapyr to be taken up by the roots of desirable plants that could be injured or killed.

Table 1. Herbicides used for control of undesirable plant species
Active Ingredient1	Products	Availability
Glyphosate 3 lb/gal	Roundup Pro, Glyphos, Glypro Plus, Touchdown Pro	Farm supply stores. Containers 2½ gallons and up.
Glyphosate 3.7 lb/gal	Roundup Super Concentrate	Retail garden supply stores. Containers as small as 1 quart.
Triclopyr amine 3 lb/gal	Garlon 3A	Farm supply stores.Containers 2½ gallons and up.
Triclopyr amine, 0.59 lb/gal	Brush Killer	Retail garden supply stores. Containers as smallas 1 quart.
Triclopyr amine 0.54 lb/gal	Brush-B-Gon	Retail garden supply stores. Containers as small as 1 quart.
Triclopyr ester 4 lb/gal	Garlon 4	Farm supply stores. Containers 2½ gallons and up.
Triclopyr ester 0.75 lb/gal	Pathfinder II	Farm supply stores. Containers 2½ gallons and up.
Triclopyr ester 0.75 lb/ga	Vine-X	Internet. Pint and 12 ounce containers.
1Active ingredient is reported as acid equivalent.

Triclopyr amine - Commonly used herbicide products that contain triclopyr amine are Garlon 3A, Brush-B-Gon, and Brush Killer (Table 1). Garlon 3A is a concentrated product (3 lb triclopyr per gal), packaged only in large volume (2.5 gal or larger), and available only at farm supply stores. Brush-B-Gon and Brush Killer are more dilute than Garlon 3A, are packaged in small containers (quart containers), and can be purchased at retail garden supply centers. They are readily available and convenient for the small property owner to use.

Triclopyr ester - Commonly used herbicide products that contain triclopyr ester are Garlon 4 and Pathfinder II. Garlon 4 is a concentrated product that is diluted in water or oil before use. Pathfinder II is pre-diluted in oil and ready to use. Both Garlon 4 and Pathfinder II are packaged in no smaller than 2.5 gal containers and available from farm supply stores. Vine-X is a new product that contains triclopyr ester ready-mixed in oil and sold in small applicator containers. It can be ordered on the Internet at www.vine-x.com.

Glyphosate - Roundup Super Concentrate is similar to the glyphosate-containing products used by professional land managers. Roundup Super Concentrate can be purchased in small containers from retail garden supply stores. Products that are more dilute than Roundup Super Concentrate also are available (not discussed in this article).

Methods for Removing Undesirable Plants

Hand-pulling - Newly emerged seedlings of woody plants, such as ash, elm and maple, frequently appear in home landscapes. Homeowners should be vigilant for these; when discovered early enough, they can be removed by hand pulling. The use of a foliar applied herbicide can make the job easier for large numbers of plants.

Small trees in the landscape can be removed with the aid of hand pulling tools like the Weed Wrench^TM or the Root Talon. The Weed Wrench^TM is a manually operated, all-steel tool designed to remove woody plants by uprooting. The wrench has a vertical handle that is used to gain leverage. The base plate is placed on the ground next to the target plant to act as a fulcrum point. Two short arms with opposed gripping jaws are placed around the stem of the plant to be uprooted. As the woody plant is placed inside the jaws, the operator pulls down on the handle, and the jaws close on the stem. The leverage generated by the wrench pulls the plant and the roots system out of the ground. Mechanical specifications and prices for the various models can be found on the company's website at www.weedwrench.com.

The Root Talon is an inexpensive, lightweight alternative to the Weed Wrench^TM. It is a tool shaped like a pick-axe, but with a specialized fork and gripping flange that will let you grab onto a plant and pull it out of the ground. The Root Talon does not give you the pulling strength of a Weed Wrench™ but its weight and price makes it pretty attractive. Detailed information is available from the manufacturer, Lampe Design, LLC in St. Paul, MN. Phone: (651)699-4963.

Stump Grinding - When trees are cut down, the stumps are often ground out below the soil surface with a stump-grinding machine. This serves to remove the stump from view but adds additional costs to the tree removal. Costs for stump grinding are based on size and location of the stump to be removed. Information on sprouting of various tree species following stump grinding is not available but some species may re-grow from the stump or remaining roots. If root sprouts occur, they can be controlled using one of the herbicide application methods listed below.

Foliar Herbicide Application - Foliar application refers to applying herbicide to the leaves (foliage) of unwanted plants. Seedling trees and shrubs can be controlled in this way with Brush-B-Gon, Brush Killer, or Roundup Super Concentrate. All are diluted in water before application. The herbicide solution should be applied so that it contacts only the unwanted plant because it will kill most plants that it comes in contact with.

Cut Stump Herbicide Application - Stumps of some undesirable plants will resprout after cutting if not treated with a herbicide. Resprouts can be continually cut off as they appear, but applying herbicide to the stump will kill it and prevent resprouting. Stumps should be cut as close to the ground and as level as possible so that applied herbicide does not run off onto the ground. On large stumps, the herbicide should be concentrated just inside the bark. This is where the living tissue of the trunk is that will carry herbicide into the roots. Products that contain triclopyr amine, triclopyr ester, or glyphosate are effective for controlling regrowth of stumps of many undesirable species. Homeowners with only one or a few stumps to treat can use Brush-B-Gon, Brush Killer, or Roundup Super Concentrate. All three products can be applied undiluted. The stump should be free of sawdust and the herbicide applied as quickly as possible after cutting.

Basal Bark Herbicide Application - Woody plants can be killed without cutting the tree down by applying oil soluble herbicide to the bark of the stem. This is only recommended for trees or shrubs with stem diameters of six inches or less. This method is faster than cutting vegetation down and treating the stumps. It is useful for homeowners with larger numbers of woody plants to kill where it is acceptable to leave dying and dead vegetation standing. An oil soluble herbicide must be used for basal bark application to facilitate movement of the herbicide through waxy substances in the bark. Garlon 4 must be diluted in a penetrating oil that can be recommended where the herbicide is purchased. Pathfinder II is pre-diluted in oil and ready to use. Vine-X can be used for application to small stems (up to ¾ inch in diameter).

Frill and spray. Photo credit: Doug Courneya

Frill or Girdle Herbicide Application - Basal bark application will not be effective on trees with bark that is too thick for herbicide to penetrate. In this case, some bark must be removed before application of herbicide. A sharp implement such as a machete or hatchet is used to make cuts through the bark and herbicide is applied into these cuts. Cuts 3 to 4 inches apart (frill) are sufficient some species, while a continuous cut completely around the trunk (girdle) is necessary for hard to control species such as cottonwood. Either water soluble or oil soluble herbicide may be used.

Herbicide Use and Safety Anyone who applies pesticides on lawns and ornamentals as a business, or anyone who applies pesticides to their own business property or employees who apply pesticides to their employer's business property, or any government employee who applies pesticides to lawns and ornamental plants, must be licensed according to the provisions of Minnesota state law. Additional information on pesticide licensing can be obtained at the University of Minnesota Extension Service, Pesticide Safety and Environmental Education web site at www.extension.umn.edu/pesticides/.

A license is not required to purchase or apply on your own (non-business) property any of the herbicides discussed in this article. A yard maintenance person who applies a pesticide to the lawn or ornamental plants of an individual residential property is exempted from licensing and certification requirements if the pesticides are owned and supplied by the individual property owner. Unlicensed yard maintenance people cannot advertise for, or solicit, pest control business and cannot represent themselves to the public as being engaged in pest control. Unlicensed yard maintenance people cannot supply their own pesticide application equipment, use pesticide application power equipment or use any equipment other than a handheld container when applying pesticides.

It is essential and required by law for anyone using a herbicide (or any pesticide) to follow the "Directions for Use" on the manufacturer's label. Training and information on pesticide use and safety is recommended for anyone who applies their own pesticides and is provided by the University of Minnesota Extension Service. Check out the web site at www.extension.umn.edu.

Additional References

Hartzler, Robert G. 1999. Chemical Control of Unwanted Woody Vegetation. Iowa State University Extension, Forestry Extension Notes F-341.

Heiligmann, Randall B. 1997. Controlling Undesirable Trees, Shrubs, and Vines in Your Woodland. The Ohio State University Extension, Factsheet F-45-97.

Howard, Scott W. and Robert Parker. 1995. Chemical Control for Woody Plants, Stumps and Trees. Washington State University Extension, Extension Bulletin EB1551.

McNabb, Ken. 2004. Environmental Safety of Forestry Herbicides. University of Alabama Cooperative Extension System, Publication ANR-846.

Motooka, Philip, Guy Nagai, Lincoln Ching, John Powley, Glenn Teves, and Alton Arakaki. 1999. Woody Plant Control for the Home, Pasture, and Forest. University of Hawaii Cooperative Extension Service, CTAHR Publication WC-4.

For additional pictures herbicide application techniques, see: Controlling Buckthorn by Doug Courneya, Regional Extension Educator.

Brown Recluse Review and Update
Jeffrey Hahn, Assist. Extension Entomologist

Brown recluse Photo credit: Dept. of Entomology, Univ. of Minnesota

Every year there are people in Minnesota that believe they have been bitten by a brown recluse spider, Loxosceles reclusa, or have this condition diagnosed by a physician. A spider is virtually never seen in connection to the purported bites. But a necrotic wound develops which is the basis for the diagnosis. However, these diagnoses need to be tempered due to several facts about brown recluse.

Fact 1. The brown recluse spider does not occur in Minnesota. The brown recluse is native to states in the south central part of the country, from Kansas, Oklahoma, most of Texas east to Kentucky, Tennessee, and western Georgia and north to southern Iowa, Illinois and Indiana. Minnesota is too far north and is not considered part of this spider's normal range. It is possible that someone could accidently bring this spider into Minnesota but this appears to be rare.

An interesting survey recently conducted by Dr. Richard Vetter, an entomologist in California, examined the distribution of the brown recluse, http://hermia.esa.catchword.org/vl=6418440/cl=69/nw=1/rpsv/cw/esa/00222585/v42n4/s3/p512. He made an open invitation on the internet to examine spiders that people believed were brown recluse. He received 1,773 arachnids from 49 states including six specimens from Minnesota. Spiders in 38 families and 88 genera were submitted as well as windscorpions and harvestmen (e.g. daddy-longlegs).

He discovered that people that sent samples from endemic states (i.e. where the brown recluse is native), submitted a brown recluse (or related species) 32 - 89% of the time. However, in states that are mostly or completely outside the known brown recluse geographic range, 25 out of 29 them did not submit any spiders that were a brown recluse. One brown recluse was found in northern California and three (all from the same shed) were found in Virginia. There were also two cases of a related species, Loxosceles rufescens, found outside its normal range, one in Colorado and two found in the same building in Pennsylvania. None of the six spiders submitted from Minnesota were brown recluse or a related spider.

Dr. Vetter concluded that the general public perceives that the brown recluse is widely distributed throughout the U.S. While this spider is frequently submitted from endemic areas, they are virtually never found in areas outside their historic geographic range. He states that brown recluse spiders, and their bites, are restricted to areas where they traditionally have been found. This strongly suggests that not only is Minnesota outside of the known brown recluse distribution area but they are very rarely transported into the state.

This conclusion is corroborated by spider specimens sent to the Entomology Dept. at the University of Minnesota. In at least 21 years (the length of time the author has been at the U of M), there has never been a verified brown recluse spider submitted.

Brown recluse range Map credit: Burke Museum, Univ. of Washington'

Fact 2. Brown recluse spiders are reluctant to bite humans.

People get an image in their mind, perhaps from movies like Arachnophobia, that spiders are aggressive and go out of their way to bite people. The truth is that spiders in general are quite shy and avoid people whenever possible. This is particularly true about brown recluse spiders. People in Minnesota have a tendency to become very alarmed when they believe there is the possibility of a single brown recluse. People in brown recluse endemic areas do not usually give this spider a second thought. It is common to trap dozens of brown recluse from a home without any of the occupants receiving bites.

One dramatic case chronicles a family of four in Kansas, a state where brown recluse spiders are common, http://docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/00222585/v39n6s25.pdf. In a six month period 2,055 brown recluse were collected of which nearly 500 were large enough to bite a person. Despite the large number that was present in the home, none of the family members received any bites. This tells us that a high population of brown recluse spiders need to be present before it is reasonable to expect bites. In non-endemic states, such as Minnesota, the odds of receiving a brown recluse bite is extremely low.

Fact 3. It is not possible to diagnose a brown recluse spider bite by just examining the wound.

There is a mistaken belief that the only cause of a necrotic wound, i.e. death of tissue at a localized site, is through the bite of a brown recluse. In fact, there are literally dozens of other explanations, http://spiders.ucr.edu/necrotic.html. Amongst the most common would be infections of Staphylococcus. Any wound or break in the skin could allow entry of this bacteria. Other causes of necrotic lesions can be due to other bacterial infections as well as viral or fungal infections, vascular or lymphoproliferative (e.g. lymphoma) problems, Lyme disease, diabetic ulcer, chemical burns, and a variety of other problems.

You can not call a lesion a brown recluse bite unless you have captured a spider that was caught in the act of biting and was positively identified by an expert as a brown recluse spider. Brown recluse is not native to Minnesota and the odds of it being transported here is very rare. The chance of being bitten by this spider is remote. People experiencing unknown necrotic lesions would be much better served to explore other, more common, possible causes rather than pursing brown recluse as the only explanation.

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

October Garden Calendar
Compiled from conversations with Bob Mugaas and Patrick Weicherding, Regional Extension Educators

Parking lot victim Photo credit: Beth Jarvis

Trees and Shrubs:
Dying inside needles on confierous trees is nothing to fear. It is fall needle drop and very normal. It will be the oldest, innermost needles on branches of spruce, pine, fir, etc. Arborvitae lose "fans" of needles.

Still need to water evergreen trees and shrubs until the soil freezes. Deciduous trees and shrubs need water until they drop their leaves.

Regardless, mulch, mulch, mulch. Mulch will help insulate the soil in case of no snow and retains soil moisture.

Storm damaged trees have been a hot topic. Here are some resources for you:
The Extension Urban Forestery site on storm-damaged trees:
http://www.cnr.umn.edu/FR/extension/stormdamage1.html

Trees and shrubs with storm-damaged branches need to be cleaned up/removed. Such wounds are avenues of entry for insect and disease. You don't need wound dressing but the broken portions should be properly pruned to branch collars or other appropriate point.Treating storm damage
When to hire an arborist

Think about winter protection for newly planted trees and shrubs--rodent protection and sun scald protection/tree guards. Plan to have the task done by Thanksgiving. That stretchy tree wrap is no longer recommended. Use plastic tubes with ventilation holes or tie boards to the south-southeast side of the tree.

You can still plant containerized trees and shrubs until mid-October. Keep them well watered and don't fertilize.

Lawns:
As leaves begin to fall, you can mow them into the lawn. Mulching mowers make short work of a light covering of leaves. If you mow on a regular basis, chances are you won't exceed the amount of leaves you can mow into the lawn. When you're done, your lawn should look as if it's been raked. If you can see shredded leaves on top of the grass, rake the excess up. Leaves covering the grass blocks sunlight to the grass plants.

Some trees dump all their leaves in a short period of time. You may need to put the bagger on the mower and collect the leaves at least once. Chopped leaves and grass clippings make a great mulch for shrubs. (They can also go into the compost pile.)

Dry leaves shred best but you might wish to wear a dust mask as chopping them up can be a dusty task.

If you still need to fertilize your lawn, wait until mid-October if you live in the northern part of the state or Halloween to early November if you live in the southern part. Apply nitrogen at a rate of 1 pound per 1,000 square feet. A likely fertilizer ratio will be 4-0-3 (sold, for example as: 16-0-12, 20-0-15, 24-0-18 etc.)

If bare patches are taunting you, you can try dormant seeding in late October. You need to work the seed into the soil and water it well and hope the soil freezes. It's a bit of a gamble. The window of opportunity stays open until early November. Good soil to seed contact is imperative. Just scattering seeds on bare ground won't work.

On dormant seeded areas, delay using any herbicide next spring until lawn has been mowed 3-4 times. This also particularly includes means pre-emergence for crabgrass.

As long as the daytime temperatures remain in the 55-60 degree range, there's still time to apply broadleaf weed control products. When daytime temperatures drop below 55 degrees, it's too late.

Sodding can be done thru mid-late October. Water it in. Exposed sites, especially, should be watered frequently to keep the sod from drying out. There is a greater risk, the later you wait, of the sod drying out before it roots in. Ask your sod vendor about any gurantees.

Fruits, Flowers and Veggies:

Elephant's ear has tender bulbs Photo credit: Beth Jarvis

Fretting about freesias? Question about caladiums? Uncertain when to dig dahlias? Most tender bulbs need to be dug once they're hit by frost. Here is the info on when and how: Storing Tender Bulbs and Bulblike Structures. Spring bulbs should be planted now. Tulips can go in last.

Remove diseased plants and their foliage and dispose of it all. Compost piles don't get warm enough to destroy disease organisms.

Apples can withstand a light frost so if it dips down into the mid-20s, don't fear. Just keep your toasty warm fingers off them until the ambient temps arise above freezing and the apples warm. Otherwise, you'll leave bruises in the apples. If you're not sure if they're ripe, look at the seeds. If they're dark brown, the apples are ripe.

Raspberry canes that bore fruit this summer can be snipped off at the ground and destroyed. Any tender green canes or any that fruited this fall can be retainedas they'll set fruit next summer.

Blueberry shrubs might benefit from winter protection. A cylinder of 1/4" hardware cloth wide enough to surround the shrubs and 3 to 4 feet tall will reduce both critter and freeze damage. (The mesh is apparently able to reflect/deflect enough sunlight.)

Editorial Notes

Wool-mulched strawberry plants and canola. Photo credit: Beth Jarvis

This image was taken of an experimental strawberry plot that uses wool mulch and canola to retard weeds. The plants in the aisles are canola. The wool blanket lasts 2 years but this research is about growing strawberries as annuals. They're planted in August, produce fruit the following summer and are replaced in August.

With the October issue, we return to monthly publication, around the first of the month.

For November 1, Patrick Weicherding will write about on-going research at the U that's evaluating whether butterflying, scoring or teasing apart circling roots in container-grown trees makes a difference in the establishment of trees. He'd planned to do it for October 1 but had some complications.

By November 1, we should be able to tell you all about the latest apple release from the U's apple breeding program.

Some time this winter, we'll have more on the new mums. Prior to spring perennial ordering, Bob Mugaas will provide the data from the two year perennial evaluation program that he, Janna Beckerman and a host of Master Gardeners conducted.

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.)

The Yard & Garden Clinic closed December 12, 2003 due to budget cuts. Questions from the general public will no longer be accepted. Samples will not be accepted.

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


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