Invasive Exotic Plant Tutorial - Russian olive and Autumn olive MC

Species Management and Control Information

Russian olive and Autumn olive
Elaeagnus angustifolia L. and Elaeagnus umbellata Thunberg.

Source: The following information is taken from a number of sources and those sources are identified at the beginning of the referenced information. The intent of this resource is to provide the user with as much of the information that exists for management and control of this species as is practical. It is important to note that new and improved methods are added regularly which will require you to visit the websites provided for updates on this information. Bibliographies and resources referenced by these sources are not included here, but are included at the websites from which this information was extracted.

READ THIS FIRST!

Before administering any of the following management and control options, it is imperative that you are familiar with the background information provided under the General Management and Control Section.

For additional, and potentially more current, information on management and control of this species, use the Mid-Atlantic Exotic Pest Plant Council (MA-EPPC) listserve or any of the other listserves identified in the Resource - Listserve section of this tutorial. You will find directions for subscribing to the list serve there. The MA-EPPC listserve has an archives feature that saves past discussions (beginning in 1999) about specific species control. These messages are at: http://groups.yahoo.com/group/ma-eppc/messages.

GENERAL MANAGEMENT CONSIDERATIONS:

National Park Service and U.S. Fish and Wildlife Service - Plant Invaders of Mid-Atlantic Natural Areas - Autumn Olive - http://www.nps.gov/plants/alien/pubs/midatlantic/toc.htm - 2002

Do not plant autumn olive.

Plant Conservation Alliance - Alien Plant Working Group - WeedS Gone Wild - Fact sheet - Russian olive - http://www.nps.gov/plants/alien/fact/elan1.htm - Authors: Rose-Marie Muzika and Jil M. Swearingen - March 28, 2005.

Mowing hedges with a brush type mower, followed by removal of cut material may be the most effective method for eradication. Herbivorous animals are not known to feed on it and few insects seem to utilize or bother it. Canker disease is occasionally a problem but not enough to be useful as a control agent.

The Nature Conservancy - Invasive Species Initiative - Species Management Summary (ESA or Element Stewardship Abstract): Russian olive - http://tncweeds.ucdavis.edu/esadocs/elaeangu.html - Author: Mandy Tu - July 2003.

Potential for Restoration of Invaded Sites:
Large mature stands of E. angustifolia are nearly impossible to eradicate throughout an entire watershed once it becomes well-established, so the early detection and rapid response to treat newly detected populations of E. angustifolia is important. Small patches of E. angustifolia, however, can be adequately controlled using a variety of control methods. All control techniques used to manage E. angustifolia are labor-intensive and expensive, especially in the first year of large-scale E. angustifolia removal. Mowing, cutting, burning, excavation, spraying, girdling, and bulldozing have all been used for E. angustifolia control, and they all work to reduce aboveground biomass, sometimes to varying degrees of success. Successful long-term control of E. angustifolia requires that all control sites to be continually monitored and follow-up treatments vigilantly applied for several years, since E. angustifolia frequently resprouts or develops root suckers from the root crown.

Along regulated-rivers, once E. angustifolia trees have been killed and/or removed, the ensuing restoration of native trees and shrubs can be improved by simulating historic flood regimes and rates of water drawdown at the time of cottonwood seed dispersal (Friedman 1993, in Shafroth et al. 1995). In some situations, the planting of poles or nursery stock of native trees and shrubs can assist in the re-establishment of native riparian communities (Shafroth et al. 1995).

The Nature Conservancy - Invasive Species Initiative - Species Management Summary (ESA or Element Stewardship Abstract): Autumn olive - http://tncweeds.ucdavis.edu/esadocs/elaeumbe.html - Author: N. Sather, Nancy Eckardt, Tunyalee Martin - August 28, 1987.

Elaeagnus umbellata seems to be a problem only in locations where small stands or rows were planted, usually within the last 10-20 years, and have begun to spread into adjacent fields or natural areas. It apparently can become troublesome where it occurs on or next to prairies with infrequent prescribed burns because it resprouts quickly after fire damage or cutting.

MANUAL AND MECHANICAL CONTROL:

Delaware River Invasive Plant Partnership - Invasive Plant Fact Sheets - Autumn Olive and Russian Olive - http://www.paflora.org/DRIPP.html - Authors: Ann F. Rhoads and Timothy A. Block - April 2002.

Seedlings and sprouts can be pulled by hand when the soil is moist enough to insure removal of the root system. On larger plants, cutting alone results in thicker, denser growth upon resprouting. Burning during the dormant season also results in vigorous production of new shoots.

Illinois Nature Preserves Commission - Vegetation Management Guidelines - Autumn Olive - Vo. 1, No. 3 - http://www.inhs.uiuc.edu/chf/outreach/VMG/VMG.html - Author: Bob Szafoni - February 6, 1990.

RECOMMENDED PRACTICES IN NATURAL COMMUNITIES OF HIGH QUALITY: Young seedlings and sprouts can be handpulled in early spring when adequate ground moisture is present to allow removal of the root system along with above- ground growth. Autumn olive is easily seen in early spring because its leaves appear while most native vegetation is still dormant.

National Park Service and U.S. Fish and Wildlife Service - Plant Invaders of Mid-Atlantic Natural Areas - Autumn Olive - http://www.nps.gov/plants/alien/pubs/midatlantic/toc.htm - 2002

Individual young plants can be hand-pulled, ensuring that roots are removed. Cutting, in combination with herbicide application, is effective.

Ohio Department of Natural Resources - Division of Natural Areas and Preserves - Invasive Plants of Ohio Fact Sheet # 7 - Autumn Olive and Russian Olive - http://www.dnr.state.oh.us/dnap/invasive/ - January 8, 2003

Hand-pulling seedlings and sprouts is effective in the early spring when the ground is moist and the entire plant and root system can be removed. Other forms of control, such as mowing and burning, without the application of a herbicide usually contribute to a larger number of root sprouts.

Southeast Exotic Pest Plant Council - Invasive Plant Manual - Autumn Olive - http://www.se-eppc.org/manual/autolive.html - 2003

Cutting: Cut trees at ground level with power or manual saws. Cutting is most effective when trees have begun to flower to prevent seed production. Because autumn olive spreads by suckering, resprouts are common after treatment. Cutting is an initial control measure, and success will require either an herbicidal control or repeated cutting of resprouts.

Girdling: Use this method on large trees where the use of herbicides is not practical. Using a hand-axe, make a cut through the bark encircling the base of the tree, approximately 15 cm (6 in) above the ground. Be sure that the cut goes well into or below the cambium layer. This method will kill the top of the tree but resprouts are common, and may require follow-up treatments for several years until roots are exhausted.

Hand Pulling: Autumn olive is effectively controlled by manual removal of young seedlings. Plants should be pulled as soon as they are large enough to grasp, but before they produce seeds. Seedlings are best pulled after a rain when the soil is loose. The entire root must be removed since broken fragments may resprout.

E. angustifolia seedlings and sprouts can be hand-pulled or weed wrenched out when soil is moist (Deiter 2000). Saplings with a trunk diameter less than 3.5 inches can be pulled sufficiently with a weed wrench (Deiter 2000). Pulling or digging out larger plants is both extremely labor-intensive and not recommended, since it can leave behind root fragments that can resprout. Seedlings can also be continually mowed for good control, but larger plants respond to cutting or girdling by vigorously resprouting, resulting in thicker, denser growth, unless herbicide is immediately applied to cut surfaces after cutting.

Virginia Department of Conservation and Natural Resources and Virginia Native Plant Society - Invasive Plant Species of Virginia Fact Sheets - http://www.dcr.virginia.gov/dnh/invlist.htm

Seedlings and sprouts can be handpulled when the soil is moist to insure removal of the root system. On larger plants, cutting alone results in thicker, denser growth. Burning during the dormant season also results in vigorous resprouting.

GRAZING:

West Virginia University Extension Service and USDA Natural Resource Conservation Services - Control of Autumn Olive, Multiflora Rose and Tartarian Honeysuckle - http://www.caf.wvu.edu/~forage/5412.htm - Authors: Jamey Darlington, USDA Natural Resource Conservation Service and Bruce M. Loyd, West Virginia University Extension Service - August 1994

Biological control is the use of animals to control brush. Goats and sheep are two examples of live-stock that will eat brush. In fact, goats often prefer brush. Mixed classes of livestock (sheep and cattle; goats and cattle, etc.) may be more effective overall due to the preference of each species for certain forages. A strong boundary fence is essential when using different species of livestock.

Use of goats and sheep must be part of a plan for pasture management and utilization. Some important aspects of pasture management are (l) good fences, (2) rotating pastures, (3) no grazing before grasses are 3 to 6 inches tall, and (4) soil fertility management based on soil test recommendations. Grass will increase as the amount of brush decreases, but pastures will have to be carefully managed to control and minimize soil erosion during grazing.

Unlike sheep or cattle, goats will defoliate and debark bushes, saplings, and small trees. Thorny vegetation does not deter them. By standing on their hind legs, goats defoliate higher up on many plants than sheep do. Goats will generally defoliate multiflora rose stems to a height of 5 feet. Goats outperformed sheep in a comparative study at WVU. Sheep required three sea-sons to accomplish the same reduction in brush cover that goats accomplished in one season.

Spring and early summer are critical times for goat and sheep control of brush. Eight to 10 mature goats or sheep per acre may be required early in the season, but this stocking rate may be reduced later when pasture growth slows. One must consider grazing management and soil fertility when looking at stocking rates. Although goats can clear brush from a pasture in one season, actual plant kill of brush requires continued grazing management for several seasons.

The key to control is repeated heavy defoliation in spring and early summer without overgrazing the grasses and legumes. Thus a rotation system works best. Using a mixture of goats, sheep, and cattle will provide the most effective clearing and subsequent plant kill of multiflora rose in pastures. More goats are suggested during the first season; their number can be reduced after two or three seasons.

Autumn olive and multiflora rose are readily eaten by goats and sheep. Livestock does not readily eat tartarian honeysuckle, but goats may browse it when plant is young and small.

PRESCRIBED FIRE:

Illinois Nature Preserves Commission - Vegetation Management Guidelines - Autumn Olive - Vo. 1, No. 3 - http://www.inhs.uiuc.edu/chf/outreach/VMG/VMG.html - Author: Bob Szafoni - February 6, 1990.

Prescribed burning has not proven effective in controlling established autumn olive.

Small seedlings of E. angustifolia may be susceptible to fire, but burning alone does not adequately control larger individuals of E. angustifolia, since it can vigorously re-sprout following fire (similar to cutting or mowing). Prescribed burning, however, can be used as either a pretreatment to, or used in combination with another control method, called integrated pest management (IPM).

BIOCONTROL:

National Park Service and U.S. Fish and Wildlife Service - Plant Invaders of Mid-Atlantic Natural Areas - Autumn Olive - http://www.nps.gov/plants/alien/pubs/midatlantic/toc.htm - 2002

Herbivorous animals are not known to feed on it and few insects seem to utilize or bother it. Canker disease is occasionally a problem but not enough to be useful as a control agent.

Currently there are no biological controls for Autumn-olive or Russian-olive.

The Nature Conservancy - Invasive Species Initiative - Species Management Summary (ESA or Element Stewardship Abstract) - Russian olive - http://tncweeds.ucdavis.edu/esadocs/elaeangu.html - Author: Mandy Tu - July 2003.

There are no reported biocontrol agents for the control of E. angustifolia.

CHEMICAL CONTROL*:

Delaware River Invasive Plant Partnership - Invasive Plant Fact Sheets - Autumn Olive and Russian Olive - http://www.paflora.org/DRIPP.html - Authors: Ann F. Rhoads and Timothy A. Block - April 2002.

Glyphosate can be used to control larger plants. Foliar application has proven effective in controlling these species. Since glyphosate is nonselective and will affect all green vegetation, care should be taken to avoid impacting native plants. At sites where this is a concern, application of the herbicide to the freshly cut stumps of the invasive shrubs should achieve the desired results. This method minimizes damage to other plants.

Illinois Nature Preserves Commission - Vegetation Management Guidelines - Autumn Olive - Vol. 1, No. 3 - http://www.inhs.uiuc.edu/chf/outreach/VMG/VMG.html - Author: Bob Szafoni - February 6, 1990.

RECOMMENDED PRACTICES IN NATURAL COMMUNITIES OF HIGH QUALITY: Cutting the plant off at the main stem and applying herbicide to the stump has been effective in killing root systems and preventing resprouting. Roundup herbicide (a formulation of glyphosate) has been effective in controlling autumn olive when used as a 10-20% solution and applied directly to the cut stump. Although the Roundup label specifies a higher concentration for cut-stump application (50-100%), this lower concentration has proven effective. Roundup can be applied either by spraying individual stumps with a low pressure hand-held sprayer or else by wiping each stump using a sponge applicator (sponge-type paint applicators can be used). With cut-stump treatment, herbicide is applied specifically to the target plant, reducing the possibilities of damaging nearby, desirable vegetation. Cut-stump treatment is particularly effective late in the growing season (July-September), but is also effective during the dormant season. Glyphosate is a nonselective herbicide, so care should be taken to avoid contacting nontarget species.

RECOMMENDED PRACTICES ON BUFFER AND SEVERELY DISTURBED SITES: Foliar application of dicamba herbicides (available under the tradename Banvel) and 2,4-d herbicides (available under a variety of brand names,including Crossbow) can provide total kill with little or no regrowth the following year. Banvel is mixed at the rate of 1 oz. per gallon of water plus 1/2 oz. of surfactant. The 2,4-D herbicide should be mixed according to label instructions. One hundred percent coverage of foliage should be achieved during the growing season (April-September). Therefore, this control measure is best suited to shorter plants. Although application can be done any time during the growing season, summer application (July-August) is especially effective. Banvel and 2,4-D are selective against broadleaf plants, so care must be taken to avoid contacting desirable, broadleaf vegetation. Do not spray so heavily that herbicide drips off the target species. Foliar spray of herbicides should only be used in less sensitive areas because of problems with contacting nontarget species. The herbicide should be applied while backing away from treated areas to avoid walking through the wet herbicide.

Although glyphosate (Roundup) is an effective foliar spray when applied during the growing season, it is not recommended because it is nonselective. Use of this herbicide as a foliar spray can result in unnecessary damage to target species.

National Park Service and U.S. Fish and Wildlife Service - Plant Invaders of Mid-Atlantic Natural Areas - Autumn Olive - http://www.nps.gov/plants/alien/pubs/midatlantic/toc.htm - 2002

Hedges can be cut down using a brush type mower, chain saw, or similar tool, and stumps treated with a systemic herbicide like glyphosate or triclopyr. Application of these herbicides to foliage is also effective but is likely to impact non-target species.

Systemic herbicides, such as Roundup®, Glypro®, Garlon 3A®, and Garlon 4® can be used effectively when applied to cut stumps or when used as a foliar spray. A small amount of Tordon Kit in the mixture will control resprouting. Basal bark application of Garlon 4® with Penevator Basal Oil® can also be an effective form of control.

Southeast Exotic Pest Plant Council - Invasive Plant Manual - Autumn Olive - http://www.se-eppc.org/manual/autolive.html - 2003

Foliar Spray Method: This method should be considered for large thickets of autumn olive seedlings where risk to non-target species is minimal. Air temperature should be above 65Â°F to ensure absorption of herbicides.

Cut Stump Method: This control method should be considered when treating individual trees or where the presence of desirable species preclude foliar application. Stump treatments can be used as long as the ground is not frozen.

Basal Bark Method: This method is effective throughout the year as long as the ground is not frozen. Apply a mixture of 25% triclopyr and 75% horticultural oil to the basal parts of the tree to a height of 30-38 cm (12-15 in) from the ground. Thorough wetting is necessary for good control; spray until run-off is noticeable at the ground line.

Seedlings, saplings, and mature E. angustifolia trees can all be effectively killed by the careful, judicious, and targeted application of herbicide. Foliar and basal bark applications can be effective, especially for young individuals or for resprouts, but there may be off-target effects (from overspray or drift) if applied as a foliar spray to large stands. The most specific herbicide application technique for large mature trees is the cut-stump application method. First cut the stem/trunk as close to the ground as possible, then immediately (within a few minutes) brush-on or squirt herbicide onto the cambium layer of that cut-stump. Hacking and frilling ("hack and squirt"), girdling plus herbicide, or injection of herbicide, are also all effective at killing mature trees.

Glyphosate (e.g. RoundUp®) and triclopyr ester (e.g. Garlon 4®) have both been reported to be effective in killing mature E. angustifolia trees (Parker & Williamson 1996). Caplan (2002) reported excellent kill rates using a 50% solution of Garlon 4® in a cut-stump treatment (herbicide applied within 5 minutes of cutting) on trees with trunks less than 4 inches (10 cm) in diameter in New Mexico. This may not be effective on trees with trunks larger than 8 inches in diameter (Caplan 2002). Caplan (2002) then followed-up the cutting treatments with foliar sprays on root sprouts for the following two years (25% solution of Garlon 4®), and reports that instead of large dense stands of E. angustifolia, he now finds on average, less than 3 sprouts per acre. He adds that continued vigilance, monitoring, and follow-up treatments are necessary for long-term success.

Edelen and Crowder (1997) eliminated E angustifolia trees in Washington State by cutting them in mid-summer, and then mowing the re-sprouts once in late summer the following year. While effective, this non-herbicidal method was labor intensive and costly. They decided that their next efforts would include using herbicide to first kill the trees before removal. They used imazapyr (e.g. Contain® or Arsenal®) at different concentrations, and found that Contain® (used in a 4% solution; 14% active ingredient) damaged about 75% of the trees. Large trees showed damage in the upper half of canopy, while younger trees and sprouts were strongly affected throughout their entire canopy. When Garlon 4® (triclopyr) was applied as an aerial spray (no concentrations given), they reported a 90% kill rate (W. Crowder, pers. comm.).

Parker and Williamson (1996) report that basal bark applications (spraying herbicide directly onto the bottom 60 cm [2 feet] of each stem) with triclopyr (e.g. Garlon 4®or Remedy®) appeared to give effective control. They added that with these basal applications, top-kill is excellent, and this method minimizes soil disturbance and maintains other desirable vegetation. Parker and Williamson (1995) also stressed that it is important that applications completely wet the entire circumference of all stems or clumps of stems, but not to the point of run-off. The basal bark method is effective with small trees with smooth bark. For larger trees, the sprayed area must extend upward to include some smooth bark. Treatment of larger trees with thick, rough bark using this method may provide only about 50% control. The best time to apply herbicide is when the plants are actively growing from May through September. Parker and Williamson (1996) recommend that burning is effective in large stands for first reducing biomass, and then basal applications should be used on resprouts.

Since burning and cutting stimulate resprouting, herbicide treatment may be necessary to eradicate large patches. One method of application is to cut the plant off at the main stem and paint the herbicide on the stump. Glyphosate is effective and commonly used. Kurz (pers. comm.) and Nyboer (pers. comm.) recommended a 10-20% dilution for painting on stumps. Foliar applications may be adequate for small patches; the recommended dilution of glyphosate in this case is a 1-2% solution. Kurz (pers. comm.) stated that the best time for herbicide application is in late August or September when the plant is actively translocating materials to the roots.

Kuhns (1986) reported that March dormant season basal applications (stem injections) of triclopyr alone or in combination with 2,4-D provided excellent control of autumn olive at very low concentrations (down to 1% triclopyr in diesel oil). The lowest concentrations of triclopyr and all treatments with the 2,4- D/triclopyr combinations provided slower kills than higher concentrations of triclopyr alone, but only one of the treatment plants were expected to survive (Kuhns 1986). Foliar applications of 2,4-D, triclopyr or metsulfuron methyl in late May or June at recommended rates did not provide adequate control, and even plants that were severely injured recovered the following year. Dicamba applied in late June at 4 lbs/gal (2 qts/100 gal/acre) with a surfactant provided 90% total kill and severely retarded the growth of surviving stems the following year (Kuhns 1986). Glyphosate was not included in this study.

Ohlenbusch and Ritty (1979) reported excellent results for the control of russian olive (E. angustifolia) in Kansas using a variety of herbicides and treatments. Applications were made on June 14 and results evaluated in late August. Foliar applications of dicamba, picloram, and glyphosate, all in a 90% water/10% diesel oil carrier, resulted in total root kill. However, glyphosate in both 1% and 2% solutions damaged herbaceous plants under the trees so extensively that foliar application of this chemical is not recommended.

Basal application of triclopyr, all mixed in diesel oil and applied June 14, also resulted in 100% control. A second study by the same authors indicated that diesel oil alone also provides highly effective basal control of E. angustifolia (Ohlenbusch and Ritty 1979).

USDA Forest Service - Nonnative Invasive Plants of Southern Forests: a field guide for identification and control - Autumn Olive - http://www.invasive.org/eastern/srs/AO.html - Gen. Tech. Rep. SRS-62. Asheville, NC - Author: James H. Miller - 2003.

Virginia Department of Conservation and Natural Resources and VA Native Plant Society - Invasive Plant Species of Virginia Fact Sheets - http://www.dcr.virginia.gov/dnh/invlist.htm

A glyphosate herbicide can be used to control larger plants. Foliar application has proven effective in controlling these species. Since glyphosate is nonselective and will affect all green vegetation, care should be taken to avoid impacting native plant species. At sites where this is a concern, application of the herbicide to the freshly cut stumps of the invasive shrub should achieve the desired results. This method minimizes damage to other plants. Glyphosate herbicides are recommended because they are biodegradable, breaking down into harmless components on contact with the soil. To be safe and effective, herbicide use requires careful knowledge of the chemicals, appropriate concentrations, and the effective method and timing of their application. Consult an agricultural extension agent or a natural resource specialist for more details on herbicide control measures.

* Mention of pesticide products in this document does not constitute endorsement of any particular material.

FAILED OR INEFFECTIVE PRACTICES: Repeated pruning of established plants to ground level without subsequent herbicide application is not effective for autumn olive control. Each regrowth results in a thicker stem base and denser branches.