Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Client's Request via email (preceded by telephone conversation at 925- 608-6683).
Thanks for your interest in our distressed navel orange tree. Here is the information you requested from our phone conversation and some photos. My 60 - 80 (?) year old orange tree has, for the three years we have lived here, regularly produced abundant crops of many hundreds of exceptionally delicious fruit each year, February - June.
In the last four weeks it has been dropping oranges at an increasing rate, by now many dozens a day, totaling over 300.
It is over two stories tall and grows in Martinez, California, in a moderate climate with hot summers and cool winters.
As you can see from the photos, the fruit is splitting, leaves are drooping, the canopy is diminishing, and a few clusters of branches have died. There is a tree nearby of the same age and size that does not appear to have any problem at all.
Our tree has not been watered regularly during the dry season, whereas the neighboring tree is surrounded by a watered lawn.
It was given a fertilization of nitrogen last year, and we wonder if this, or the lack of watering, could be the cause.
What can we do to save this magnificent tree?
MGCC Help Desk Response: Thank you for contacting the UC Master Gardener Program Help Desk with your primary issue that your orange tree's fruit splitting and also the leaves are drooping and turning over
Splitting citrus fruit is a common problem, especially with navel oranges. The following link (http://anrcatalog.ucanr.edu/pdf/8038.pdf) is a short 1-1/2 page informative UC document which describes the condition, along with suggestions for resolution.
Very briefly, fruit splitting is likely the result of stress to the tree, and is probably related to extreme fluctuations in temperature, humidity, soil moisture, and possibly fertilizer levels. The disorder is often caused by a combination of these factors rather than by a single cause.
Avoiding fluctuations in soil moisture (I suggest adding mulch under the tree canopy and consistent and ample water, especially during heat spells) as well as fertilizer levels throughout the growing season may help to minimize fruit split.
I believe the leaf drooping and turning over are also symptoms of too little water during the hot season. The dropping of leaves and resulting thinning of canopy often are the result of too little water on both fruit and ornamental trees.
I am also including some additional links which will provide information on growing healthy citrus here in Contra Costa County. In particular take a look at the 2nd link below as that will provide you with assistance on watering and fertilizing.
http://ucanr.edu/blogs/slomggarden/blogfiles/4260.pdf
http://homeorchard.ucanr.edu/Fruits_&_Nuts/Citrus/
Please let us know if you have any additional questions!
Help Desk of the UC Master Gardener Program of Contra Costa County (EDC)
Note: UC Master Gardeners Program of Contra Costa's Help Desk is available almost year-round to answer your gardening questions. Except for a few holidays (e.g., last 2 weeks December), we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone: (925) 608-6683, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/. MGCC Blogs can be found at http://ccmg.ignore.edu/HortCoCo/ You can also subscribe to the Blog.
Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Client's Request: I am very excited because I just built some new raised beds for vegetables in my back yard. Previously, I have used mainly Earth Boxes and miscellaneous pots. But with the new garden area, I was wondering how best to mulch. In previous times, I used lawn clippings ‐ available free in my yard or from my neighbors. Now, my lawn is gone along with many others of my neighbors. I do have an abundance of last year's oak leaves, but I wondered if they might not be good for the plants. What is your opinion of using newspaper? Is hay (or straw) a good choice? Though I would have to buy that. Other suggestions?
Help Desk Response: Thank you for contacting the UC Master Gardener Program Help Desk with your question about mulches. Most mulches help suppress weeds and retain moisture. Organic mulches (plant based) will decompose slowly and add nutrients to the soil. It is important to note that because soil organisms use nitrogen as they decompose the mulch, it should be used only on the surface to avoid nutrient deficiencies. Nitrogen eventually returns to the soil as organisms die.
For garden areas that are worked annually (your vegetable beds, for instance), it is best to use mulches that break down rapidly, such as rice straw, dried grass clippings or alfalfa. Oak leaves would be good to use for this, as long as they don't get matted down and prevent water from passing through. Shredding the leaves by running a lawn mower over them would prevent the matting if you experience the problem.
Newspapers could also work, but we wouldn't use them as a stand‐alone mulch. You may need to shred the newspaper some so that they aren't subject to matting. Newspapers can also easily blow away and looks a bit unsightly. You could layer another mulch material over it if you do choose to use it.
Straw is good for vegetable gardens. It is light weight and will break down over time. Make sure you use straw which shouldn't have weed seeds, while hay often contains copious weed seeds.
You want to stay away from bark or wood mulches because they take a long time to decompose, and you will need to rake them off whenever you change your vegetable crops.
To help in your decision on which mulch to use, I've attached a summary of the various types of mulches with their pros and cons. Please let us know if you have further questions.
Happy gardening!
Help Desk of the UC Master Gardener Program of Contra Costa County (SEH)
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/).
Mulch 6 Mar 2017
Advice for the Home Gardener from the Help Desk of the
UC Master Gardener Program Contra Costa County
Gardener's Request: I'm a new homeowner with a garden with clay soil apparently and trees that are now dropping leaves. How do I garden with clay soil and what should I do with the dropping tree leaves – use them in the gardening and how or disposing of them in my green bin?
MGCC's Help Desk Response: Thank you for contacting the UC Master Gardeners Program's Help Desk with your questions about gardening in clay soil, and whether to remove leaves from the landscape or incorporate them into the existing soil.
First, about gardening in your clay soil:
Your clay is made up of air, water, organic materials, and minerals. The balance of these ingredients determines your soil type. Clay soils are those that are often rich with nutrients, and renowned for their water retention capabilities, but can become compacted over time, creating a less hospitable environment for plants. This link provides information from UC Davis discussing how to work with your clay soil to get the best results. http://vric.ucdavis.edu/pdf/soil_managingclay.pdf
One of the most essential components to gardening in clay soil is creating good tilth (i.e., ability to grow plants, especially from seed). This is accomplished by carefully adding organic matter such as manure, compost, and/or planting cover crops to your existing soil. This article by a Marin County master gardener discusses the many ways that you can improve the tilth of a clay soil with organic matter. http://www.marinij.com/article/NO/20160304/FEATURES/160309921
Use of fallen tree leaves in the garden:
pix: UCANR
Thank you for submitting your questions, and I wish you luck in your gardening decisions.
Help Desk of the UC Master Gardeners Program of Contra Costa (JJM)
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/).
Help for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Client Request: I have several eucalyptus trees on my property. They shed a lot of leaves. I'd like to use the leaves for mulch and possibly compost, but when I research these uses, I get confusing and/or contrary guidance. My request: Can I use eucalyptus leaves/cuttings as mulch and/or compost in the home garden?
Help Desk Response: We understand your frustration with the information you're finding on the use of eucalyptus leaves as mulch. In doing the research on your question, I too, found a lot of conflicting information. The Master Gardener Program is under the umbrella of the University of California so the information that follows is all based upon scientific research.
Eucalyptus Toxicity
While it is true that eucalyptus leaves do have some toxicity, the research shows that well composted eucalyptus leaves pose no problem when used as a mulch or when mixed at appropriate quantities into a growing medium. The research also concluded that fresh eucalyptus leaves were shown to be a good weed suppressant when applied to a depth of 4 inches (10cm).
Following are two articles by James Downer & Ben Faber on the subject of eucalyptus mulch and eucalyptus compost.
http://ceventura.ucanr.edu/newsletters/Volume_23_No129817.pdf
and
http://slosson.ucdavis.edu/newsletters/Downer_199429100.pdf
Composting
The University of California research concluded that, when handled properly, eucalyptus is safe for use in compost (i.e., incorporated into the growing medium). The toxicity of the eucalyptus are rendered harmless by the composting process, especially if you are working a hot compost pile. (See http://vric.ucdavis.edu/pdf/compost_rapidcompost.pdf)
When composting eucalyptus, the leaves are considered green plant material and will constitute the nitrogen part of the composting process. To effectively use eucalyptus clippings or leaves, you will want to mix them thoroughly with carbon-based materials such as newspaper, cardboard or other dry leaves or plant material.
The University researchers suggest, if you still have concerns, that you consider composting eucalyptus in a separate hot compost pile, keeping the pile well moistened and turning it often to keep the mix hot over a longer period of time.
Once the eucalyptus is well composted you can do a germination test to test for toxicity by using the compost as a medium to start 10-12 fast growing seeds such as radishes. If a majority of the seeds germinate, the eucalyptus toxicity can be considered neutralized by the composting process.
If you want to use fresh eucalyptus leaves in your landscape, the conclusion suggests to favor using them on the woody landscape plants in the home garden setting.
I hope this gives you the information you were looking for and sets your mind at ease.
Help Desk of the UC Master Gardener Program of Contra Costa County (BHD)
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
UC Master Gardener Program of Contra Costa County
Generally, used appropriately, coffee grounds can be beneficial to your garden. And if you search the internet you can find lots of information on their use. As in all things “internet”, the question is “what is appropriate”.
The Master Gardener program attempts to provide the gardener with scientifically based advice on gardening. The use of coffee grounds is no exception. Recently, Washington State University's Dr. Linda Chalker-Scott (Extension Urban Horticulturist and Associate Professor, Puyallup Research and Extension Center, Washington State University) updated her earlier 2009 review of gardening use of coffee grounds with the publishing of her latest review of the scientific literature: “Use Of Coffee Grounds In Gardens And Landscapes” (http://cru.cahe.wsu.edu/CEPublications/FS207E/FS207E.pdf). This latest review has been peer-reviewed.
While it is strongly recommended that you read for yourself the short 6-page paper, below are the edited excerpts from her findings:
Action list for using coffee grounds in compost
- Use no more than 20 percent by volume of coffee grounds in a compost pile. A diverse feedstock will ensure a healthy diversity of microorganisms.
- Don't assume coffee grounds will make an acidic compost; pH levels will change over time.
- Be sure to allow coffee grounds to cool before adding them to your compost; heat can kill your beneficial microbes.
- Avoid adding coffee grounds to vermicomposting bins; they can injure or kill earthworms in these confined areas.
- Understand that disease suppression from nonpathogenic organisms found in decomposing coffee grounds has only been demonstrated under controlled conditions on a handful of crops, including bean, melon, spinach, and tomato. Their efficacy in gardens and landscapes is unknown.
Action list for using coffee grounds directly as a mulch
- Apply a thin layer (no more than half an inch) of coffee grounds. Cover with a thicker layer (four inches) of coarse organic mulch like wood chips. This will protect the coffee grounds from compaction.
- Don't apply thick layers of coffee grounds as a standalone mulch. Because they are finely textured and easily compacted, coffee grounds can interfere with moisture and air movement in soils.
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BLOG editor's addendum: Most of the comments on Dr. Chalker-Scott's latest review center around “avoid adding coffee grounds to vermicomposting bins…” with more than a few anecdotal comments that it is common practice to use coffee grounds in compost bins. I think there is some clarification needed between compost bins and vermicompost bins… Her response so far is that she is reporting what is in the scientific literature. Vermicomposters should take special notice of this finding and manage their composting accordingly. You might search for further updates and discussion on Dr. Chalker-Scott's Facebook page “The Garden Professors”
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Help Desk of the UC Master Gardeners of Contra Costa County
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/).
