How can homeowners drastically reduce irrigation and still maintain a viable and pleasing garden? There are many garden practices that can help conserve and maximize water use.  By implementing these, even with less water, plants are able to survive summer heat and drying winds. One effective water management strategy is irrigation by hydrozones.

Start by drawing a plan of your property indicating your trees, shrubs, annuals, lawn, a vegetable garden and other plants.  Circle and group plants with similar water needs in hydrozones.  Separate hydrozones could include lawn/turfgrass, mass plantings or annual flowers, mass plantings or perennial flowers, non-turf perennial ground covers, and individual trees and shrubs.  Not sure of your plants' watering needs?  Find out the water requirements of specific plants, by clicking on the link: http://ucanr.edu/sites/WUCOLS/.

Design a system with multiple independent zones so you can schedule irrigation according to each area's watering needs.   Use a variety of irrigation methods and convert to drip irrigation where possible.  To guide you in adjusting and resetting irrigation controllers as weather and seasons change, use UC's Easy Calculator for estimating water needs.   You can also explore that site to find out about ET zone maps (ET refers to evapotranspiration).  You'll see that Contra Costa County has 3 zones: 1,8 and 14. 

Grouping of plants with similar watering needs could also include plants with similar root depths, plants that prefer shade or full sun, or plants located on a slope.  Providing you keep your irrigation systems in good working order and with proper planning, irrigating plants according to hydrozones means plants receive only the quantity of water they need. No wasted water or overwatered plants!  

Since it is difficult to maintain large plantings of vegetables and bedding annuals during a drought,  consider reducing their size or eliminating them altogether. Doing this would allow water to be directed to more valued or expensive perennial plantings such as fruit trees which are considered a high irrigation priority.  Consider reducing your lawn hydrozone area and expand your patio or deck to allow air and water to reach the root zone of trees.

Maximize your water use in all hydrozones by following these beneficial garden practices.  Apply 2 to 4 inches of mulch to slow down evaporation, inhibit weeds and keep soil cool.  Add organic matter, such as compost to the soil.  Water established plants deeply and infrequently.  Water slowly and evenly around the drip line of trees using low pressure and applying water to a minimum of four sites around the perimeter.  To keep evaporative loss to a minimum, water early in the morning, when the wind is down and temperatures are cool.  Keep plants out of the wind. Familiarize yourself with your soil type and water infiltration rate as this will help avoid runoff.

By understanding the water needs of plants, drought gardeners can care for many types of plants, even with reduced irrigation.  Grouping plants into hydrozones and watering them according to their needs is a proven effective water management solution.

 

 

 

 

For more about evapotranspiration, see UC's Evapotranspiration and Plant Water Use

 

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

Client's Request for Information and Advice:

I live in central Contra Costa County and have a very large Sycamore tree in my front yard. I would guess it's height at 40 to 50 feet. It has an 8 1/2 foot circumference, and many large branches have grown over my house. I am not sure how old it is, but my guess is that it is at least as old as the house, which is 65 years old. It was here when I moved in, which was 35 years ago -- and it was very large then.

The tree has received water from the lawn that surrounds it, although I am now cutting back to watering only every two weeks due to the drought, which I understand should be sufficient for the tree. It has not been pruned except occasionally to keep it out of the power lines. Large roots are visible on the surface of the lawn. I believe the only fertilizer it has received would have been when the lawn was fertilized, which hasn't occurred for probably ten years.

Sycamore tree branches over roof

My question concerns the branches that are growing over my house. Are Sycamores of this size safe growing over a house, or should I have those branches pruned back?

I hesitate to contact a tree pruner, as I am not confident that they would give me an accurate, unbiased answer since it would be in their interest to suggest that pruning was necessary.

MGCC's Help Desk Response:
Thank you for contacting the Master Gardener Help Desk.

You are right to be concerned about your tree, especially during the drought. Trees on residential properties can add value to the property, provide a pleasant setting for the house, neighborhood and community, shade from the hot summer sun, and a “sense of place”. There would no doubt be different neighborhoods without our trees. Because of these factors, homeowners taking good care of their trees are usually amply rewarded.

Your Sycamore tree is probably a California Sycamore (Platanus racemosa), a widely planted residential tree for its beauty and shade which can live for over 150 years. While generally easy to get along with, Sycamores do have their problems at times, namely Anthracnose and Powdery Mildew (see http://www.ipm.ucdavis.edu/PMG/GARDEN/PLANTS/sycamore.html). Overall though these are usually minor irritants to the homeowner if the tree is properly cared for, e.g. watering to maintain its health, and some pruning to provide for appropriate growth.

However, our research find that Sycamores are known to experience a phenomenon called "Summer Branch Drop". More information about this phenomenon can be found at this link from the Journal of Arboriculture. (http://bit.ly/1HormZb) 

While Master Gardeners can provide advice and appropriate references on the care of your Sycamore, we are not professional arborists, especially for significant concerns such as yours. From the pictures of the overhanging branches, it would seem that an assessment of the health and well-being of your Sycamore by a professional arborist is appropriate. While the cost of professional consultation is not insubstantial, the payback in peace-of-mind and protection of your investment in the tree and house could be substantial. So, in spite of your misgivings about the motivations of a tree service company, we would strongly advise that you have your tree inspected and evaluated by a certified arborist, probably a consulting arborist to provide a neutral 3^rd party evaluation. Certification of arborists is by the International Society of Arborists (ISA). Some certified arborists are independent consultants while others are associated with specific tree care companies. While the independent consultant's consultation is probably close to a given fee, you should be able to request an estimate from any tree maintenance company for their proposed work. UC provides some advice on dealing with contractors and consultants at this link (http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74125.html).

ISA Certified Arborists in our area  can be found at this link http://www.isa-arbor.com/findanarborist/findanarborist.aspx. Once on line at the ISA page, to find an arborist in our area, use the Search by location function. Choose United States from the pull down menu, then type in the zip code and radius of interest (25 miles should be more than ample) and search again. This will bring up a list of certified arborists who work in our area as well as distinguishing who that are associated with and/or an independent consultant.  My search found that there are many certified arborists to choose from in our area.

It appears that the tree has been receiving reasonable cultural care. Fertilizing established trees is usually not necessary. Your watering schedule may be sufficient, but we recommend that you speak with the arborist about caring for your tree during the drought as well, especially since you have exposed roots.

I hope that this information is helpful. Please do not hesitate to contact us again if you need further assistance.

Help Desk of the Master Gardeners of Contra Costa

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Note: The  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/

Advice from the Master Gardeners of Contra Costa's Help Desk

The Client's Concerns and Requests:

I have a Ficus benjamina which has white waxy globules on the base of many of the it's leaves (see picture right). I've had this tree a long time and I'm concerned it's somehow diseased. I don't want to lose it. Could you tell what the globules are please? What concerns I should have about the health of the tree?... and some guidance on keeping the tree healthy and alive?

Response from the MGCC Help Desk:
Thanks for bringing the Ficus benjamina (Weeping Fig) leaf samples and photos into the MGCC office this morning. Having a sample made it easy to see the white sticky globs at the base of each leaf. When we looked at the leaf under the microscope, there were no insects present on the leaf or under the white waxy substance. We also looked at another Ficus growing in our office and found that it, too, had the same white sticky globules on the base of each leaf.

Ficus benjamina
potted indoors

After further research, we discovered that there are several cultivars of Ficus benjamina which have a dark black “wax” or “phenolic” gland at the base of each leaf which secretes latex to attract fig wasps that pollinate the tree in nature. The white substance you are seeing is a latex leakage which crystallizes when exposed to air. The reproductive systems of species in the genus Ficus are unique. A University of Hawaii article on Ficus benjamina explains that each species of Ficus has an associated species of agaonid wasp and pollination can only occur when that specific wasp is present. Your plant is trying to attract a tiny little pollinator wasp which in all probability has not been introduced to our area. I don't believe that the white substance you have is anything to worry about. If you are concerned about the aesthetics of the white spots, you might try wiping and/or washing them off. Curiously I noticed that the heat of the microsope caused them to liquefy and drip off! For more information on the special leaf gland on some Ficus cultivars, see the University of Florida article http://hortsci.ashspublications.org/content/34/6/1051.full.pdf.

You also mentioned that you might also have a sticky substance in the middle of the lower surface of some of the leaves. If these are in locations where they wouldn't be a drip from the leaf gland of possibly a nearby leaf, it is possible that you might have scale or another sucking insect. As I mentioned, we didn't see anything under the microscope. You might want to examine your leaves, and contact us if you do see any signs of scale or other insect. (Although not a UC guidance document, the UC references cited in the article on Ficus Benjamina Pests” at http://homeguides.sfgate.com/ficus-benjamina-pests-40044.html would be the primary UC guidance MGCC would use to determine appropriate care if there were pests on your Ficus.)

Ficus are notoriously finicky about water, light, and transplanting. From the picture you provided, it looks like you have a nice light filled location for your tree. Because the back corner is dark, it is a good idea to frequently rotate the pot. You mentioned that some of the leaves are turning yellow. Yellowing leaves can be a sign that it is either getting too much or not enough water. (We did mention that Ficus are finicky?) You said that you water your plant once a month, just until runoff, and that the roots are “tight”. It may be that the root ball is very compacted and not able to take up enough water because the water is quickly running through the pot. One method of helping to get the root ball to take up water we would propose would be that several times a year when you water the plant, completely submerse the pot in a tub, bucket or pot of water. Leave it for several hours, giving the rootball a change to become fully saturated. You will want to drain off any free flowing water when you remove your plant from the tub/bucket/pot. After that continue watering as usual.

Regarding repotting, check the roots of your Ficus tree to determine if/when it is time to repot the Ficus. If the pot appears crowded with roots and there is little soil left, your Ficus has probably become root-bound and needs to be repotted. When repotting, after removing the tree from the pot, brush the soil away from the root ball to assess how badly root-bound the Ficus has become. If some of the roots have begun to circle around the ball, carefully unwind them with your fingers. Gently separate the roots in the root ball, releasing any dirt that may have been clogging it. Cut off any dead or rotten roots using a small pair of gardening scissors or pruning shears. If any of the roots have begun to grow through the drainage hole in the pot, prune these back as well. Select a new pot that is 1 or 2 inches wider in diameter than the old pot. Fill the bottom with several inches of fresh potting soil, place the tree into the pot, and backfill with new potting soil to cover the roots and stabilize the tree. Often when their environment is changed, whether a change in water, light, rotating the plant, or transplanting there is a chance the Ficus will drop its leaves - but in time they should grow back.

Feel free to contact us if you have any additional questions.

Happy gardening with a great indoor plant.

Master Gardeners of Contra Costa's Help Desk

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Note: The  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/