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From the UC Blogosphere...

Sorry, This Blossom Is Taken

A male Svastra dive-bombs another male on a Mexican sunflower (Tithonia). This image was taken with a fast shutter speed of 1/3200 of a second. (Photo by Kathy Keatley Garvey)

So here's this male longhorned bee (Svastra) sipping a little nectar from a Mexican sunflower (Tithonia). As the late Mr....

Posted on Wednesday, July 18, 2018 at 5:00 PM

Ready for Moth Night at UC Davis?

These are Atlas moths (Attacus atlas), found in the rain forests of Asia. This moth has a wingspan that can measure 10 to 11 inches. (Photo by Kathy Keatley Garvey)

Are you ready to celebrate Moth Night at the Bohart Museum of Entomology at the University of California, Davis? Mark...

Posted on Tuesday, July 17, 2018 at 4:24 PM

Saving a Butterfly: In a World Where Kindness Matters

Newly eclosed anise swallowtail, Papilio zelicaon. (Photo by Kathy Keatley Garvey)

It was a long awaited process, but it's a girl! And she's beautiful! It all began with finding two anise swallowtail...

Posted on Monday, July 16, 2018 at 3:39 PM

Citrus And Avocados




Citrus And Avocados

By Leslie E. Stevens   UCCE Master Gardener


Do my citrus and avocado trees need any special care in the summer? Carol P. Arroyo Grande 



It's a good idea to keep an eye on these valuable trees, making sure they have sufficient water and aren't overwhelmed by pests and diseases.  Citrus and avocado trees may require extra water to offset excessive evaporation during periods of hot dry weather. At the same time avoid overwatering, especially near the trunk, which can lead to root and crown rots.


Healthy citrus trees can withstand most minor pest invasions except for Asian citrus psyllid, a tiny mottled brown insect that is a vector for a bacterium responsible for the fatal citrus disease Huanglongbing (HLB). The disease can kill all commonly grown citrus varieties within five years of inoculation, and there is currently no known cure. If you suspect you have this insect among your citrus trees, call the CDFA Pest Hotline: 1-800-491-1899.


Avocado trees also have their share of pests, including the pesky persea mite. Feeding damage causes visible spots on leaves which can lead to leaf drop and sunburned fruit.  Reduce minor infestations in home gardens with strong water sprays, less frequent fertilizing and encouraging natural enemies. Treat heavier mite populations with insecticidal soap and water sprays.


These and other tips for growing healthy citrus and avocado trees will be covered during this Saturday's free “Advice to Grow By” workshop presented by UC Master Gardeners. Informational handouts will be available at this three-part workshop, and audience questions are encouraged following each presentation.


The outdoor workshop runs from 10 a.m. to 12 p.m. at the Garden of the Seven Sisters, 2156 Sierra Way, San Luis Obispo.Docents will be available after the workshop to answer questions until 1 p.m. Remember to bring a hat, sunscreen and water and join your fellow gardeners in the garden.

For more information about UCCE Master Gardeners or to register for workshops, visit our website at http://ucanr.edu/sites/mgslo/

Posted on Monday, July 16, 2018 at 1:29 PM
  • Author: Leslie E. Stevens
  • Editor: Noni Todd

Veggie Planting Guides

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

Client's Request:  Hello, I am a Master Gardener from San Juan County in WA and have recently come to reside off Alhambra Valley Road in Martinez and would like to start planning the reestablishment of a fantastic residential garden space, both Vegetables and flowers. If you have a planting guide for this area I would like to get it via email if possible. Thank you.

UCMGCC Help Desk Response:   Welcome to California.  As a fellow Master Gardener, we are pleased that you thought to contact our UC Master Gardener Program Help Desk with your questions about gardening in our area.  While our climate here in Contra Costa County is no doubt drier than you're used to (particularly in summer months), once you get used to it, you'll find you can raise some wonderful vegetables and flowers.

You're a bit on the late side for starting many summer veggies, but just in time to start planning a winter garden.  In Central Contra Costa County where you reside, late August and early September is an ideal time to start many winter crops such as broccoli, romanesco, cauliflower and other brassicas as well as carrots, beets and other root vegetables. As you requested, I have attached a PDF copy of our vegetable planting guide for interior regions of the County. (The interior and Bayside veggie planting guides can both be found at http://ccmg.ucanr.edu/EdibleGardening/VegetablesforContraCosta/.

Unfortunately, we do not have a similar Master Gardeners planting guide for flowering plants.   I can tell you, however, that particularly for low water use plants, the fall months are a good time to start new flowering plants. Typically our winter rainy starts about mid October. In "normal" rainfall years, the rains can provide the generous water amounts that even drought tolerant plants need to get established. Planting in the fall months will allow you to get started with plants that will begin to flower next spring and summer.

There are many resources that can help you select  flowering plants that are suitable for growing in our climate.  One that we particularly like is a plant selection tool from the UC Davis Arboretum which allows you to search their “UC Davis All-Stars”. The UC Davis All-Stars are 100 plants selected by the UC Davis horticultural staff for their toughness, reliability, ease of growth, low water requirements, and few problems with pests or diseases. The following URL allows you to search the All-Stars for plants that may be of interest to you:  http://arboretum.ucdavis.edu/plant_search.aspx. You can search by plant name or plant characteristic including, at a minimum, type of plant (in your case, you would select Perennial), size (small, medium, large), exposure (full sun, part sun, shade), and whether you want California natives only. Clicking on “show/hide more criteria” allows you to narrow your search further according to water needs, flower season, flower color, and wildlife value.

If you would like to see more options, there are other websites with larger plant databases. Two such sites are:  The Contra Costa Water District'shttp://www.contracosta.watersavingplants.com/search.php. The Contra Costa Water District website provides access to an extensive database of native and non-native plants for their area. The link provided above allows you to go on a guided tour through the database. Like the UC Davis site, it allows you to select plants based on type (trees, perennials, annuals, ground covers, etc.) and within type by various characteristics including size, sun requirements, soil-type (sandy, loam, clay), color, blooming season. Note that you will need to check the Culture for water usage. This database includes some medium water users as well as many low and very low water users.
Calscape http://calscape.cnps.org/ Calscape, which is a collaboration between the California Native Plant Society (CNPS) and the UC Berkeley Jepsom Herbarium, contains California native plants only. Calscape emphasizes the selection of natives local to your area. To begin your search, enter your location: Martinez, CA. From there you can search by plant type (tree, shrub, perennial, etc.), exposure (sun, part shade, shade), or by special category (bird and buttrfly). You can also search by plant name. Note that you need to check the water needs in the description; not all California natives for Contra Costa County are drought-tolerant.

Finally, I suggest that you consider attending our "Fall for Plants Gardening Workshop” which will be held on Sept. 8, 2018, at our Demonstration Garden in Walnut Creek. We'll be selling both winter vegetable starts and some drought tolerant plants at the event.   You can watch for more information about the event on our website:  http://ccmg.ucanr.edu/.
You are most welcome to contact us again if you have further questions.
Help Desk of the UC Master Gardener Program of Contra Costa County (TKL)

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, although we will be moving late July. We will notify you when that occurs. 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 Biog  (http://ucanr.edu/blogs/CCMGBlog/)

Posted on Monday, July 16, 2018 at 12:13 AM

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