Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County

Client's Request:  I went on Tuesday evening to a very good presentation at the Lafayette Library by Master Gardeners. I had a question that the presenters could not answer and their advice was to ask it directly to the Help Desk -- so, here it is....
I have planted a new garden with native plants and have not added any amendment to support the plants' growth. I read online that mycorrhizal fungi can be added after the plant has been set in the ground and it will enable healthier root and plan growth.  Is that correct?

Help Desk Response:  Thank you for contacting the UC Master Gardener program regarding mycorrhizal fungi and your native garden. We know that plants and mycorrhizal fungi live in a symbiotic relationship, very beneficial to both species. The fungi colonize the plant roots, helping with uptake of water and minerals. It is well known that plants in healthy soils with good mycorrhizal colonization are much healthier. You can promote this by appropriate irrigation, minimizing soil disturbance by not tilling, and limiting fertilizer, especially phosphorus. Also, using a surface mulch will help.

There have been many studies on the effects of mycorrhizae on growing plants, which show definite benefits, but it is not clear that adding them to an existing landscape is helpful. There are many different species of mycorrhizae, and it seems that they need to be adapted to the particular environment or plant species, and if you add 'foreign' ones, those native fungi already present may defend their territory and your garden will receive little or no benefit. Also, one study that I know of looked at viability of commercially available mycorrhizae inoculants and found that some did not have any live ones! That being said, if you still want to try this, a reputable and appropriate source should be used.

If your garden was prepared appropriately, and the plants are healthy and thriving, and you are using mulch, it should be fine without adding the mycorrhizae. In addition, I could not find any recommendation to add mycorrhizae for this situation on the California Native Plant Society website:   http://www.cnps.org/cnps/grownative/getstarted/starting_a_garden.php

I hope this has been helpful and that your garden will thrive. If you have further questions, please feel free to contact us again.

Help Desk of the UC Master Gardener Program of Contra Costa County (SMW)

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Note: The  UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions.  Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA  94523. We can also be reached via telephone:  (925)646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog  (http://ucanr.edu/blogs/CCMGBlog/)

Advice from the Help Desk of the
Master Gardeners of Contra Costa County

Client's Request:  I've been noticing this “weed” growing in my garden lately. At least, I think it's a weed although the leaves seem to resemble some garden geraniums. Is it a weed, and if it is, what do you suggest I do to get rid of it? Some JPG photos I took of the “weed” are below. ... and (editor's addendum) can you eat it?

  

Sprouting Cheeseweed in
Contra Costa Garden

MGCC Help Desk Response:  Thank you for the photographs. The plant is a type of Mallow, probably “Little Mallow” (Malva parviflora), often also commonly called Cheeseweed for the "small wheels" of cheese like fruit it produces. And yes as the common name implies, it is a winter-sprouting annual weed or sometimes a biannual weed. It quickly develops a deep taproot, making it difficult to eradicate. Pulling them up or hoeing them off as soon as you notice them is the best way to control their spread.

Cheeseweed can also be toxic to cattle and can reduce egg quality if fed to laying hens.

Additional information on this weed and its control can be found at the University of California's website  http://www.ipm.ucdavis.edu/PMG/WEEDS/little_mallow.html  and http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74127.html.

As above, early-on mechanical (hoeing) and cultural control (weeding) are about the only effective controls for home gardeners. Control by herbicides has not proven effective. In fact, this mallow is one of the few weeds not controlled by glyphosate (i.e., RoundUp™).

I hope that this information is helpful. Good luck on controlling it. I've had them in my garden off and on for years and can't seem to keep them out although I find that if caught early enough they aren't hard to keep them at bay and aren't that much of a pest.

HOrT COCO Blog Editor Addendum: It's been brought to my attention that Cheeseweed is edible... and by quite a few cultures... but not by this gardener/editor... see the various comments on its use as greens, etc. by Googling  "is cheeseweed edible?". You are on your own for that adventure though...

Help Desk of the Master Gardeners of Contra Costa County (JL)

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Note: The  UC Master Gardeners of Contra Costa's Help Desk is available year-round to answer your gardening questions.  Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA  94523. We can also be reached via telephone:  (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/blogcore/blogroll.cfm).

 

Garden Advice from the Help Desk of the 
UC Master Gardeners of Contra Costa County

Description of the client's problem:

Our neighborhood and lawns have been inundated with crows. Do you have any suggestions for discouraging them and their destructive behaviors?

Advice from the Help Desk:
Crows have become more prevalent in Contra Costa County in the past 15 years, mainly moving in from the decreasing agricultural areas of east County. They are large (17 to 21 inches long) and intelligent birds. Crows are omnivorous, opportunistic feeders that eat a wide assortment of foods, such as grain crops in agricultural fields, seeds and fruits, insects including pest species like lawn grub larvae, bird eggs, earthworms, fish, amphibians, reptiles, carrion and road kill, and a variety of human-associated food, ranging from pet food to garbage.

If they are digging in your lawn, here is a link to information from the University of California on how to control lawn insects: http://www.ucdavis.edu/PMG/PESTNOTES/pn7476.html. Some treatments may not completely take care of the problem and there are other pests, such as raccoons and skunks, that may be causing the damage.

Scare tactics can be effective in dispersing crows. Frightening devices include loud sounds and motion-sensing water sprinklers. In a residential neighborhood you probably want to avoid noise rockets, so the motion-sensing sprinklers are your best bet. These are attached to a hose (one model has its own reservoir) and when it senses motion, it fires off high-pressure water. Some also emit ultrasonic sound but birds don't hear at that frequency so it is probably not helpful. You can do an Internet search for “motion sensing sprinklers” or you may also find them at a local nursery, hardware store or home improvement store.

Farmers have been trying to protect their fields from crows and other birds for centuries. One method is to stretch a cord or a fine wire at intervals across a field at heights about six to eight feet above the ground. Aluminum or cloth strips can also be tied to the wire. The reason why this works is not entirely clear, but the wire appears to represent an obstacle that is difficult for a flying bird to see, especially when rapid escape may be necessary. You might try temporarily stringing lines above your lawn to see if this will deter them. Another website that may be of interest is: http://icwdm.org/handbook/birds/AmericanCrows.asp.

Crows are very intelligent birds and many have become habituated to people and our attempts to discourage them. They have often lost their wariness and, unfortunately, may not respond to any of these suggestions. If you find a new and effective technique, please let us know.

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Editor's Addendum: In reviewing and preparing this blog, I also reviewed a recent web interview at http://awaytogarden.com/the-gifts-of-the-crow-with-john-marzluff/ specifically about crows by the noted ornithologist Dr. John Marzluff, professor of wildlife sciences at the University of Washington. My take-away message from the interview is that you have a formidable and intelligent garden opponent and friend in the crow. I highly recommend the web interview.
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Help Desk of the UC Master Gardeners of Contra Costa County (SEH)

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Note: The  UC Master Gardeners of Contra Costa's Help Desk is available year-round to answer your gardening questions.  Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA  94523. We can also be reached via telephone:  (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/blogcore/blogroll.cfm).

Advice for the Home Gardener from the Contra Costa Master Gardeners Help Desk

Client's Problem & Questions:

Client called and MG volunteer discussed her gopher problems… and that she didn't want to kill the gophers, possibly using cinch traps. Discussed the information on the UC Pest Note on gopher management and the various “home remedies” readily found on the web and that basically they were “snake oil”. For a “permanent” solution only exclusion, baiting, fumigation or trapping will work. Most gardeners usually end up using exclusion and/or trapping …or getting a gopher service. 

CCMG Help Desk Response
Following up on our phone conversation earlier today, you will find below the information we discussed and/or promised on the phone. I did some additional research and have included wht I found as well below. In one instance, I came across a research paper regarding gopher management in California almond orchards. The almond orchard research showed that trapping plus additional fumigation had the highest efficacy. The reason that these two methods were combined was because the research showed that as the gophers become trap shy, the additional fumigation targeted the gophers that the traps missed. I believe the lesson learned from that research it that it will probably take more than one “solution” to get effective control of your gopher population.

In your case, because you are trying to protect your vegetable patch, and your hesitation to “trap and kill” the gophers, exclusion is most likely going to be the best, most effective method. You mentioned that this was a project you might take on next spring. Here is some information on gopher wire to line your raised beds or bury around your in-ground vegetable beds. Gopher wire is specifically designed for gopher exclusion. Look for a wire mesh measuring no more than 3/4” square or diagonally. The reason for the 3/4" spacing is the holes must be small enough to keep young gophers out. This size is determined by a young gopher's shoulder girth at the weaned age of about 8 weeks. The mesh should be 20 gauge wire (thick enough to resist the chewing of gophers). Really high quality mesh will be “double galvanized” which gives it a much longer life when buried in the ground. You must either bury the wire mesh at least 2 feet deep with some surface wire barrier showing as well when encirciling in-ground plantings. For raised beds you would line the bottom and some of the side walls (see Pest Note below).

You also mentioned that you were putting in a cover crop of clover. In my research I found information about clovers and gophers that would be helpful to you. Gophers are attracted to most clovers, especially crimson clover, which is a popular cover crop. Try substituting sour clover from the family Melilotus indica. Sour clover is high in coumarin, the original source of the blood thinner Coumadin. Gophers avoid ingesting sour clover, possibly because the coumarin adversely affects their blood chemistry. Sour clover also fixes nitrogen, reseeds easily, and has flowers that attract bees. Several plants are often called sour clover, including oxalis (gophers love oxalis), so be sure to get Melilotus indica.

If you should decide to trap and are going to use a cinch trap, be sure to buy the best quality you can afford. Cheaper models may not work at best, and will maim the animal at worst. One method I read for disposal was to release the gopher from the cinch trap back into the gopher hole and bury the gopher in place, there seems to be some evidence that there is some deterrent effect to this method and has the added benefit of (maybe) adding nutrients to the soil as it decomposes. As we discussed on the phone if you use this method do a web search on setting cinch traps and get familiar with the method before you begin.
(e.g., https://www.youtube.com/watch?v=Xz2GplXB-9s).

The link below is the UC Davis IPM link to information on gopher management. It is comprehensive and will help you understand all the pros and cons of the various management options.
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7433.html#MANAGEMENT

Thanks for contacting us with your garden question, if we can be of further assistance please call us again. 

Contra Costa Master Gardeners Help Desk

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Note: The Contra Costa Master Gardener Help Desk is available year-round to answer your gardening questions.  Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA  94523. We can also be reached via telephone:  (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/