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

Request: We have lived in our house for 22 years in central County. Just the past few years we have been plagued by “no-see-ums” as the weather starts to warm. They are generally gone by the time it's hot.

Of course, the no-see-ums chase us indoors during the best time of year for gardening, socializing and enjoying the out-of-doors. Last year I spent time online researching how to prevent this pesky critter. I remember reading somewhere (?) a process for treating the yard to prevent their “hatch". Unfortunately, I can't find what I read, only how to prevent bites.

Can you help me with this? We have no lawn at the house, just trees and plants surrounded mostly by bark. I thought there was something you could spray or spread on the bark ground cover.

I will appreciate any advice you can share. Thank you in advance.

CCMG Help Desk Response:  Thank you for contacting the UC Program Master Gardner Help Desk with your question concerning those pesky No-See-Ums you are battling. My childhood was spent in Vermont where these pesky flies breed in epic proportions in the summer, making life outdoors miserable. I sympathize with your frustration.

These minuscule flies are in the Ceratopogonidae family of flies commonly known as no-see-ums, also referred to as sand flies, gnats and biting midges. This family includes more than 5,000 species, distributed worldwide, with the exception being the Antarctic and the Arctic.

Like mosquitoes, No-See-Ums lay their eggs in moist areas. Both males and females consume nectar and other sweet juices for nourishment. Females, however, will also seek out a blood meal to fuel egg production. Female No-See-Ums will bite humans, pets, livestock, wild animals and birds. They breed and develop in moist wet areas. With her need for blood satisfied, the impregnated female will seek out an appropriate place to lay her eggs, which can include water-retaining hollows in trees, muddy water, wet sand, and other similar areas. About 28 days later, adult No-See-Ums emerge and the cycle begins again. No-See-Ums can be more difficult to get rid of than mosquitoes. They are smaller than mosquitoes and more agile fliers.

The research on control leans heavily to “exclusion” techniques as opposed to chemical treatment, misting and fogging. Chemical treatments have proven, in testing, to have little to no effect. If spraying or treating with chemicals is not effective there is little sense in spending your time and money in addition to adding the pollutant to your environment. While exclusion is the preferred control method you should look your property over and make sure you do not have “wet'” breeding sites.

Exclusion techniques appear to be the most effective method of control. These include wearing protective clothing, installing ultra-fine mesh screening (US 16 Standard Mesh) in-home screens and enclosing patio and porch areas with this same fine mesh screening. If you are really determined to be outside there are also pop-up tents designed with drop-down screening fine enough to block the No-See-Ums.

Topical sprays have proven to be only barely effective but might add a bit of protection while working in the garden. You could use a mosquito repellent with DEET, in addition to wearing protective clothing.

There is some information that refers to trapping as being moderately effective to highly effective, the trap tested is the CO2 mosquito trap. A home version is not too expensive and might be worth a try. No-See-Ums and mosquitos breed in the same conditions so you would be controlling any potential mosquito population as well, it might be a win-win.

The UC information on gnats was very limited. The Bug Squad from UC Davis provides some more detailed information at https://ucanr.edu/blogs/bugsquad/index.cfm?tagname=Valley%20Black%20Gnats. The best information I found was a link to research-based information from the University of Arizona. https://cals.arizona.edu/apmc/docs/No-See-Ums-IPMShort.pdf

I hope you will find some success by employing these methods. The best method may be the passage of time and the increase in temperature.

Please do not hesitate to call us with more questions …hopefully we will find some new information on the control of No-See-Ums.

Help Desk of the UC Program of Master Gardeners of Contra Costa County (BHD)

Notes: Contra Costa MG'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.edu/HortCoCo/ You can also subscribe to the Biog.

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

Client's Request:  Hello. We would like to plant a shade tree in our backyard in mid-County. We have a fairly shallow well… and am assuming a high water table although we don't have any wet, boggy areas. We have two semi-dwarf orange trees s that we never water and they are productive and sweet. Can you recommend links for some shade trees in these conditions .... such as Crape Myrtle, deciduous Magnolia, and Japanese Maples? Thank You.

MGCC Help Desk Response:  Thank you for contacting the UC Master Gardener Program Help Desk with a question about tree selection. You didn't say how deep your well is, but the water table is probably deep enough that it won't impact trees in your landscape. Tree roots are generally found in the top 1 to 3 feet of soil, with only some sinker roots possibly venturing deeper. Trees don't usually have tap roots past the seedling stage, but rather grow roots that extend well past the dripline (outer edge of the tree's canopy). 

If you have good drainage in your soil, any tree suited for your climate should be fine. To test your drainage, dig a hole about a foot deep. Fill it with water and allow it to drain completely. Immediately refill the hole and measure the depth of the water with a ruler. Fifteen minutes later, measure the drop in water in inches, and multiply by 4 to calculate how much water drains in an hour. Ideally, you should have 1 to 6 inches drainage per hour.

The trees you specifically asked about were Crape Myrtle, deciduous Magnolia and Japanese maple. Crape Myrtles (Lagerstroemia spp.) do well in mid-county. They need full sun and seem to appreciate our hot summers. There are many varieties to choose from. This link is to an article from the Sonoma County Master Gardeners about growing Crape Myrtles: http://sonomamg.ucanr.edu/Plant_of_the_Month/Lagerstroemia_spp_Crepe_Myrtle/.

Deciduous Magnolia may not be a good choice. According to Sunset Western Garden Book, deciduous magnolias with saucer flowers do poorly in hot and dry areas. Deciduous magnolias with star flowers seem to do better, but are very slow-growing, and the variety called Star Magnolia (Magnolia stellata) stays quite small and is usually grown as a shrub.

Japanese maples (Acer palmatum) do best in cool climates and will need partial shade and protection from hot, dry wind in the hotter areas of the County. Morning sun and afternoon shade is best. The varieties with green leaves do better with more sun exposure than the varieties with red leaves or those with lacier leaves.

You might also consider Chinese pistache (Pistacia chinesis). It is well suited for our climate and makes a good shade tree. This link is to another article from the Sonoma Master gardeners:  http://sonomamg.ucanr.edu/Plant_of_the_Month/Chinese_Pistache/.

For other ideas, this link is to a searchable database where you can select aspects you want such as shade tree, deciduous, maximum height, etc. https://selectree.calpoly.edu/about. They have good descriptions of the trees, along with photographs.

If after you perform a drainage test you find you have poor drainage (less than 1 inch per hour), contact us again and we will research those trees more suitable for a boggier area. Don't hesitate to contact us if you have any questions.

I hope this information is helpful and you find a good shade tree for your yard!

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

Notes: Contra Costa MG'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.edu/HortCoCo/ You can also subscribe to the Biog.

Subject: Control of Anthracnose on Sycamore Trees

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

MGCC Help Desk Response to Sprays for Control of  Anthracnose on Sycamores:  Thank you for contacting the UC Master Gardener Program Help Desk with your question about treating anthracnose on Sycamore trees.  You have done a lot of research on this problem, so I am not sure we can tell you anything you do not already know. Sycamore, full-grown in suburbia is a large tree, and were a common tree planted usually several decades ago, but smaller lots and today's suburbia limit their planting these days. While they are often prized for their majesty (and heigh 60-100') they can e a problem from dropping branches, debris from leaves and branches, and anthracnose, especially if planted to close to a house and other trees. 

As you know, anthracnose is a fungal disease which can cause unsightly changes to Sycamore trees.  The effects on the tree can be brown spots on infected leaves to distortion of branches, cankers and dieback.  Unless signs consistently occur every year, trees are usually not seriously harmed; they just may not be aesthetically pleasing.  The fungi survive over winter on infected leaves and twigs or dead leaf litter under the trees.  Rain in the spring splashes the fungus onto new growth and starts the infection cycle again.  Infections are worse in years with heavy spring rain than those with dry springs.  The best management mechanism is to remove infected twigs, branches, nd leafs during the fall or winter to decrease the re-infection of the trees in the spring.  If there is a wet spring, spraying new growth with fungicides can be protective: however, University of California does not recommend fungicide applications for trees other than ash.  I believe you have already reviewed this document but the UC web link to the Integrative Pest Management (IPM) on anthracnose is below. http://ipm.ucanr.edu/PMG/PESTNOTES/pn7420.html

I reviewed the pesticide labels of the two products we discussed - Agri-Fos and Reliant.  If there is a difference in the products, it was not apparent to me.  It does appear that Agri-Fos is not labeled for use on sycamores for anthracnose and Reliant is allowed to be used as a foliar spray and as an injection into the tree trunk in sycamores for anthracnose.  Why these products, with the same active ingredient in the same concentration, are labeled differently is not apparent to me.  So, we forwarded this part of your question onto our local Urban IPM advisor to see if he can provide clarification on this…. And we heard back from our Urban IPM Coordinator. Here is his response:

 “Product registrants can seek wide or narrow spectrum labels, depending on targeted markets, costs, and efficacy information. In this case, the manufacturers of Reliant have included sycamore anthracnose while the manufacturers of Agri-Fos have not. It seems that Reliant is an older product that is registered for use against a very wide range of agricultural pathogens, so maybe it was cost-effective to include anthracnose. It's also likely that the inert ingredients of these two products are different. Agri-Fos, for instance, is usually injected or otherwise introduced internally, while Reliant is sprayed.

The more important consideration here is that phosphonates (active ingredients in both these products) are not considered effective sprays as per the UC IPM 'Anthracnose' 
Pest Note: http://ipm.ucanr.edu/PMG/PESTNOTES/pn7420.html

I think the last paragraph is the most important for this discussion, that phosphonates are not considered effective sprays against anthracnose."

Finally, as we discussed on the phone, you may try consulting another certified arborist to see what their recommendations for management would be.  We cannot recommend a specific company, but would recommend you find a certified arborist through the following website. https://www.treesaregood.org/findanarborist 

Best of luck and we will let you know if we find out more Please do not hesitate to contact the Help Desk again if you have more questions. 

Help Desk of the UC Master Gardener Program of Contra Costa County (SEH/SES)

Notes: Contra Costa MG'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.edu/HortCoCo/ You can also subscribe to the Blog.

Client's Request:  What bulbs can I plant in the spring?  Where can I buy them? Thanks

Help Desk's Response: Thank you for contacting the UC Master Gardener Program Help Desk with your question about bulbs that can be planted in spring. 

There are a number of bulbs that are planted in spring, although some are actually planted as early as February. Examples are amaryllis, tuberous begonias, dahlias, gladiolus, and tuberose. The UC Master Gardeners of Sacramento County have put together a list of bulbs and their planting and blooming times:  http://sacmg.ucanr.edu/Sacramento_Bulb_Planting_Schedule/ 

Note that the times are for Sacramento County. If you are in central or eastern Contra Costa County you should be able to follow the Sacramento timing. In western Contra Costa County, you may be able to plant those bulbs a bit earlier (several weeks) since there is less danger of frost. 

In terms of where to buy bulbs, I suggest checking with a local nursery. The big box and some other stores also carry them. I would suggest you carefully examine them all as the local box store where I live in central county often sells them displayed outdoors in full afternoon sun which isn't recommended as they should normally be out of direct sun and in a cool environment. Napa MG has published an excellent guide on storing bulbs (https://www.ucanr.edu/sites/ucmgnapa/files/153521.pdf). There are also many bulb growers and suppliers who sell online, and for many, they will probably be end-of-season pricing. 

I hope this helps. Let us know if you have additional questions or need further information.

Good luck with your summer-blooming bulbs!

Help Desk of the UC Master Gardener Program of Contra Costa County (ECS)
Notes: Contra Costa MG'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.edu/HortCoCo/ You can also subscribe to the Blog.