removing fairy rings in lawns

I’ve researched “fairy ring in the grass” online, but haven’t come up with any surefire solutions. Ours is about 3 feet across, with scant grass in the center. Digging it out and replacing grass or hiring a professional to apply toxic fumigants seemed logical. Any other suggestions to try?

I think physical removal is certainly a better option than applying toxic fumigants, though it requires some work. Washington State University Extension offers these recommendations for fairy ring in lawns:

Several species of fungi can cause fairy rings in lawns. The common symptoms may include a ring of dead grass with darker green grass and mushrooms on the inside and/or the outside of the ring, circular patches of darker green grass, or rings of mushrooms or puffballs appearing with or without other symptoms. Mushroom rings most commonly appear in the spring or fall when adequate moisture is present. The type of fairy ring which causes dead rings is the most damaging. The fungus feeds on decomposing organic matter such as dead tree roots and undecomposed bark mulch in the soil and makes water penetration difficult. Fairy rings are more severe on sandy soil with low fertility. Grass inside the rings may be weakened or killed and replaced with weeds and weedy grasses. Fairy rings may disappear suddenly.

Select Non-chemical Management Options as Your First Choice!!

After rewetting, reseed affected areas and fertilize and water properly.
Provide proper culture, including deep, infrequent waterings and adequate fertilization.
Rake and loosen soil in affected areas. Aerate soil and water the area deeply. A grass-type wetting agent can be used to help rewet the soil.
Remove the sod, mix soil in affected areas in the upper 6 to 8 inches of soil with a rototiller, and reseed or put new sod in the area.

Pesticides: None recommended (Revision Date:4/20/2010)

In his book, The Chemical-Free Lawn (Rodale Press, 1989), Warren Schultz says of fairy rings:
“The only sure way to eradicate the mushroom is to dig out the turf and soil to a depth of 2 feet, extending outward at least 1 foot beyond the edge of the circle. It’s also possible to slow the fungus by drenching the soil with water to a depth of 2 feet. Some turf experts recommend fertilizing the rest of the lawn heavily to mask the green color of the ring. This practice, however, may encourage other diseases [my note: heavy fertilization contributes to toxic stormwater runoff]. You may be best off learning to live with the disease.”

This information from Oregon State University (no longer available online) provides advice on removing fairy rings from lawns:

Soak Fairy Ring area daily for a month with water. Punching a number of holes in the area to be soaked will help get the water into the soil. The Fairy Ring area is often dry, hard and difficult to get water into the soil. A thorough aeration in April with a rented machine will make the job easier.
Adequate fertilizer will mask the green ring by supplying the entire lawn with extra nitrogen.
Renovation of affected area can be accomplished by removing the affected sod and soil. Cut the area 12 inches wider than the outside of the ring. Cut the sod and soil 1-2 inches deep. Remove affected material. Replace with ‘clean’ soil and replant.

controlling moss growth in garden beds

I have a small rooftop plant bed that’s full of moss. Is that an indication of sour soil, and if so, can it be sweetened with Dolomite lime?

Moss is often simply an indication of a shady site or compacted soil, but can also be an indicator of low soil pH (i.e., acid soil). I wouldn’t recommend adding lime without doing a soil test for pH (you can buy an inexpensive kit at most garden centers), and without considering the pH needs of the plants you have in the bed. You would not want to increase the alkalinity of the soil if your plants are acid-loving.

You may find this link about moss growing in garden beds (from Oregon State University) of interest. Here is an excerpt:

“Mosses grow in garden areas for the same reasons they grow in lawns: for example, deep shade, high acidity, poor drainage, and soil compaction. As in the lawn, mosses do not compete with other plants. Rather, they establish in bare areas where conditions are favorable (Cook and Whisler, 1994).

Mosses have not been shown to hinder the growth of garden plants or trees. Reasons for removal are generally aesthetic. But aesthetics are in the eye of the beholder, and mosses are commonly viewed as positive features in landscaping. For example, traditional oriental gardening holds distinctive roles for mosses (Japanese Garden Society of Oregon 1996; see also Encouraging Mosses). Furthermore, in some situations mosses may help reduce moisture loss and crusting on soil surfaces.”

parking strip vegetable gardening

I want to plant my parking strip for a vegetable garden. Do I need a permit from the city? And if so where do I get a permit?

You do not need a Street Use permit for gardening activities in the planting strip.
Here are the City of Seattle’s current guidelines for parking strip gardening.

Linden Mead, a Seattle Department of Transportation arborist, addresses one of the concerns I would have about planting edible crops next to a street:

“Although the list may not be exhaustive, and gardeners are encouraged
to be creative, they do need to follow some parameters. Plants grown
within the area equal to or less than 30 feet from an intersection
may not exceed 24″ (2 feet) in height at maturity. This is so that
visibility is adequately maintained (cars and pedestrians visible
to each other). When a planting strip is 5 feet wide or less, plants
may not exceed 36” (3 feet) in height at maturity. This is to help
assure pedestrian safety/visibility as well as to maintain pedestrian
walkways and the roadway clear of overgrowth which may impede travel
on the right-of-way. With wider strips, it is possible to put in scattered,
taller plants, if planted in the middle of the strip.

“There are also regulations about ‘hardscape’ – which may include
planting beds in the strip. Raised beds may be constructed from
timber but rocks or bricks that are easily moved (read here ‘picked
up and thrown’) are not allowed. Permits are also required to plant, prune or remove trees.”

Seattle Department of Transportation has specific information about growing food in the planting or parking strip. There are some concerns as well as a few restrictions, described here:
“SDOT prohibits fruit trees because of the slipping hazard for pedestrians from fallen fruit. For some residents, it’s their only sunny area to grow vegetables. But the planting strip is a public space, part of the public right-of-way, so it’s hard to control what pets or people do there. It can be harder to reach with water, and there may be concerns with the soil.” It is also a good idea to test the soil for contaminants before planting edible crops.

planting bamboo near a property line

Are there any restrictions to planting bamboo near a property
line? We are planting it at least 1 1/2 feet from the property line and
will be using the appropriate barrier (if planting the runner variety) or
clumping bamboo. Basically we want to regain some privacy for our yard
and house but not encroach upon the neighboring property.

Although I cannot speak to whether there are legal restrictions about
planting bamboo (this would be a question for King County Law Library), my hunch is
that as long as you take the necessary precautions to control the spread
of the plant by installing a root or rhizome barrier, it should not pose
a problem. If you intentionally planted an uncontrolled invasive plant at
the property line, it might be possible for someone to contend that it
was malicious, as mentioned below (Revised Code of Washington):

RCW 7.40.030

Malicious erection of structure may be enjoined.

An injunction may be granted to restrain the malicious erection, by any
owner or lessee of land, of any structure intended to spite, injure or
annoy an adjoining proprietor. And where any owner or lessee of land has
maliciously erected such a structure with such intent, a mandatory
injunction will lie to compel its abatement and removal.

The American Bamboo Society has helpful information (now archived) on how to control
bamboo. Here is an excerpt describing barriers:

To prevent a running bamboo from spreading, a rhizome barrier is
essential. A barrier two or three feet deep is effective. It should be
slanted outward at the top so that when the rhizomes hit the barrier they
will bend upwards. A barrier does not stop a running rhizome; it only
deflects it. The barrier should project an inch or two above ground
level. Check the barrier once a year, and cut off rhizomes that arch over
the top.

Barriers can be concrete, or metal, or plastic. The usual recommendation
is high-density polypropylene, 40 mil or heavier, glued or taped at
junctions, or clamped with stainless-steel clamps. This material comes in
rolls, or as hinged sections, and is available from some landscape
suppliers and bamboo nurseries, frequently termed root barrier. More
elaborate barriers with corner posts that hold the material at the proper
angle are also available.

One other option is to plant your bamboo in pots. Even then, you would
need to check the bottoms of the pots periodically for escaping roots.
You can also purchase lengths of bamboo fencing or willow fencing, if you
do not wish to install a heavier fence. Here is an example of willow fencing, and here is a local company, Bamboo Builders Northwest, which has examples of bamboo fencing.

controlling weevils on salal and Rhododendron

Last year I had a big problem with weevils in my salal, rhododendrons and a few other shrubs. I am not sure if they returned after putting down beneficial nematodes last fall.

Weevils are tough! You are on the right track with beneficial nematodes. It might take a few seasons to make a difference. Here is a link to information by entomologist Art Antonelli of Washington State University about controlling weevils, especially on Rhododendron.

controlling aphids on prune trees

My prune tree has tons of aphids in the leaves (also a lot of ladybugs to eat them but I am not sure the ladybugs will win out). Do I need to try to rid the tree of the aphids? If so how?

The question of whether to control aphids in your prune tree really depends on how bad the infestation is and if the tree is otherwise healthy enough to outgrow them. Often infestations like aphids are a symptom of a larger problem. The tree may be stressed out by root competition from grass or too much or not enough water, too much or not enough nitrogen. A stressed out tree is attractive to aphids, who in turn attract lady bugs.
My own mature prune tree gets covered in aphids every year. The leaves get distorted, and lady bugs come in droves. Some years I get a good harvest and some years I do not. I choose not to worry about it (I have other plants to fuss over). But if you feel the need to do something, see the HortSense website from Washington State University.

transportation of plants across state lines

I will be transporting plants from Oregon to Washington to sell to the public. Are there any restrictions, such as quarantines, that are important to know about?

You should contact the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS).

The Oregon Department of Agriculture has information on plant exports, quarantines, and permits. There are also Washington State codes about the transportation of plants that can be found in Chapter 17.24 RCW, Insect Pests and Plant Diseases. You can then click on specific sections, such as 17.24.081, Prohibited acts.

Additionally, this site makes reference to the Washington Administrative Code and includes information about standards that apply to plants and pests. See Chapter 16-402 WAC, Plant Pest Infestations and Plant Labeling standards.

You can also click on the embedded links to look at the specific standards.

online birch tree identification guides

Are there any tree identification guides online? In particular, I am interested in weeping birch.

For several excellent images of weeping birch (Betula pendula), go to
Oregon State University’s and click on Betula pendula. Look at all the images associated with this species of birch.

Also try Virginia Tech’s tree identification page.

Here are some other online tree identification guides:
What Tree Is It
University of Wisconsin’s Tree i.d.
Cal Poly’s Urban Tree Key

environmentally sensitive methods for removing Himalayan blackberry

I am wondering about an environmentally sensitive way to get rid of blackberries. I understand that mowing them consistently for 4 years works, but unfortunately this is not an option because of the terrain. If an herbicide is our only option, can you recommend one that has minimal impact?

The area is quite large – a mile long and 20 feet wide.

Invasive.org has produced a document entitled Controlling Himalayan Blackberry in the Pacific Northwest. It includes manual removal, shading, grazing, biological controls, and last-resort herbicide information. (We cannot recommend any specific herbicides, as we are not licensed pesticide handlers.)

The Northwest Coalition for Alternatives to Pesticides has information on nonchemical blackberry control.

For additional information, phone the Master Gardener’s DialExtension (King County) at 206-296-3425 (or 800-325-6165, ext.6-3425) and listen to tape #1274 about removing blackberries. However, the solutions given in this tape may apply to smaller areas, rather than the larger stand you mentioned.

An interesting idea that some people are trying locally is the use of goats.
This article in the Seattle Post-Intelligencer mentions Healing Hooves of Spokane. There is at least one company on Vashon Island which offers this service as well. Another P-I article mentions Rent-a-Ruminant.

This document from Sound Native Plants contains contact information for several such services.

on roof moss removal

I’d like to hear your thoughts about the safest way to
remove moss from the north side of my roof. I do
organic gardening, and I don’t want to contaminate the
soil with runoff.

The City of Portland had a guide to safe moss removal (formerly available online) indicating that that the most common product sold for moss removal, zinc sulfate, is a pollutant and is toxic to aquatic life. They do say that zinc strips on the roof are an alternative, but they also release zinc, and are pretreated with pesticide.

Toxic-Free Future (formerly Washington Toxics Coalition) offers several recommendations, including physical removal of the moss, landscape planning to keep the roof clear, and the aforementioned zinc strips

Oregon State University maintains a website devoted to mosses, and one page addresses the use of zinc strips as a control. Here is an excerpt:
“Zinc strips are usually considered the long-term solution to controlling mosses […] Zinc strips and galvanized flashing are apparently relatively safe and inexpensive. They effectively kill or retard the growth of mosses and fungi and appear to have effect up to 15 feet below the zinc flashing along the length of the flashing. To use: apply the rolled zinc or galvanized flashing to each side of ridge caps along the roof peaks. Place a nail down each foot of the zinc strip. With each rain zinc is released from the strip and kills the mosses below the strip. For best results remove the existing mosses prior to treatment. The active ingredient is metallic zinc.

Effectiveness: Zinc strips are considered to be effective for up to one year for most brands. The effect of galvanized flashing (example above) can persist for decades. Success rates vary with the degree of moss development and weather. Zinc strips or flashing are most effective before mosses are well developed. Physical removal of existing moss followed by installation of zinc strips or flashing is an effective long-term strategy for suppressing moss growth.

Negative Side Effects: Direct runoff from the zinc strips or flashing to surrounding vegetation, fish ponds, or water supplies should be avoided, because some contamination by zinc is likely to occur. Zinc strips should not be used with strong acids or bases.”

The PAN Pesticides Database has an entry for one type of rolled zinc strip product.

Washington Department of Ecology has a lengthy document analyzing zinc
concentrations in industrial runoff, and you can imagine that homes with
zinc strips are simply smaller contributors to this problem.

The Environmental Protection Agency lists zinc metal strips (consisting
solely of zinc metal and impurities) as minimum risk pesticides.

I think there is no easy solution, and it is a matter of deciding on a
lesser of two evils: the physical difficulties of cleaning the moss off
the roof, which is most environmentally sound, versus the relatively
small amount of pollution from using zinc strips.