- Author: Help Desk Team
Irrigation is not a ‘set and forget' thing. Your watering schedule should be adjusted each season (at least four times each year) as water needs in the landscape vary greatly from season to season. Seasonal adjustments allow us to adapt to changing weather conditions, plant growth patterns, and water availability. If your irrigation system isn't adjusted with the seasons, your plants can suffer from overwatering in the winter or underwatering in the summer.
As seasons change through the year, your plants' needs will change, too. For example, a 15-foot wide Chinese pistache tree (Pistacia chinensis) growing in Concord needs 52 gallons of water each week in July, 24 gallons per week in October, and only 8 gallons each week in January. Adjusting irrigation according to the season can decrease water use by half and your plants will be healthier.
You can calculate how much water your landscape should have for best growth. Look up the water needs of your plants in this database: https://ccuh.ucdavis.edu/wucols-db. Determine how much water is needed for each of your plants throughout the year here: https://puddle-stompers.com/waterwonk/how-much/index.php
Even knowing what your plants ‘should' need, it's best to test your soil occasionally to make sure the water you apply is getting to the right place. To test the depth of your watering, use a soil sampling tube or a small trowel to dig down 6–8 inches deep and observe the moisture level at the bottom of the hole. Get your hands dirty and learn what your soil feels like with varying moisture levels.
There can be substantial water waste when automatic watering systems are left to run on their own. Some systems come with a rain sensor function that will automatically turn off the system when it rains and others are smart controllers that adjust the schedule based on environmental factors. It might be time to upgrade your controller to take advantage of these benefits.
Some additional reminders for good irrigation practices:
Apply the right amount of water
Overwatering is more common than underwatering and can lead to more disease problems.
Water plants deeply and infrequently
The entire root zone should receive water, but let the soil dry partially in between to reduce the chance of root rot and other diseases.
Water early in the morning
Cooler temperatures and less wind will reduce evaporation, especially if using sprinklers or above-ground systems.
Avoid runoff
This happens often in clay soil and the water is simply wasted. Cycle the irrigation giving enough time for each cycle to be absorbed.
Regularly maintain your irrigation system
Check for leaks or damaged parts that could be wasting water and preventing water from getting to the right place.
Apply mulch
A 2- to 4-inch layer will reduce evaporation, minimize weed competition, and improve the soil.
See these links for more information on irrigation:
https://sonomamg.ucanr.edu/Drip_Irrigation/Drip_Irrigation_in_Different_Landscape_Situations/
https://sonomamg.ucanr.edu/Drip_Irrigation/
Help Desk of the UC Master Gardeners of Contra Costa County
Advice from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Client's Request: We moved into a house that has a large yard (1 acre). It's 20 years old and could use some updating. The sprinkler system is not efficient and we have too much grass. ($1200 water bills.) Do you have anyone that you could recommend that could put together a plan for us to update the landscaping and irrigation?
Response from the Help Desk: Thank you for contacting the UC Master Gardener Program Help Desk with your request for a recommendation for a landscape professional.
Congratulations on your new home and large yard! It is an exciting proposition to update an older landscape to be more efficient and beautiful.
The UC Master Gardeners of Contra Costa County cannot recommend any particular landscape design, construction or maintenance company. However, the following organizations, listed in alphabetical order, provide references to these professionals. This list is neither comprehensive nor all-inclusive, and no endorsement of any business or professional is intended.
American Society of Landscape Architects (ASLA) is the national professional association for landscape architects. Landscape architects typically hold a degree in landscape architecture, covering a broad range of skills and knowledge including design, planning, grading and drainage, construction, and horticulture. California requires a landscape architect to earn a license to practice. The ASLA website maintains a searchable list of members as well as photos of award winning residential projects. http://www.asla.org/ISGWeb.aspx?loadURL=firfin and
http://www.asla.org/homeandgardentips.aspx
Association of Professional Landscape Designers (APLD) This 25-year-old self-governing organization established a peer reviewed certification program based on built projects. The organization also “encourages all members adhere to a code of professional standards, to actively participate in continuing education, and to be current with state-of-the-art developments and trends throughout the field.” Their website has a search function that will help you find a local designer. https://www.apld.org/
Rescape California is a San Francisco Bay Area nonprofit organization that promotes sustainable landscaping. Qualified landscape professionals must complete a comprehensive training program and use sustainable practices. http://rescapeca.org/education/for-professionals/design-professional-training/ . (Information on their qualification program) and http://rescapeca.org/directory/ (online directory of Bay-Friendly Qualified Professionals)
Bringing Back the Natives Garden Tour is a local (Alameda & Contra Costa Counties) organization that seeks to educate and encourage the use of California native plants in home gardens. The organization provides contact information for those landscape professionals whose gardens have been featured in their tours.
http://www.bringingbackthenatives.net/find-a-designer (contact information and links to photos of gardens created by each designer)
California Landscape Contractors Association (CLCA) is a non-profit trade organization of state licensed landscape and landscape-related contractors and professionals.
http://clca.org/consumers/consumers_home.php and
http://member-clca.org/max/4DCGI/directory/contractor/index.html (directory of members)
Qualified Water Efficient Landscaper (QWEL) graduates have been trained in water-wise landscape practices including plant selection, irrigation system design and water management. QWEL maintains an online list of certified professionals in the East Bay. While the website lists all professionals under the category of non-residential, many perform residential services. http://www.qwel.net/ and
http://www.qwel.net/graduates/east%20bay/ (list of certified professionals)
While we can readily recommend you consider these organizations' members, they are only as good as their individual members, and you should also get recommendations from their clients to confirm their capabilities. Finally, we would also recommend that you pursue recommendations for these types of services from your neighbors, especially those with gardens and yards that you admire.
Hope you find the above information helpful! Please let us know if you have any additional questions.
Help Desk of the UC Master Gardener Program of Contra Costa County (SLH)
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 this spring. We will notify you if/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 Blog (http://ucanr.edu/blogs/CCMGBlog/)
Advice from the Help Desk of the
UC Master Gardener Program of Contra Costa
Help Desk Client: My mature 40 foot redwood trees seem to be showing signs of stress from the continuing drought. While it gets just as much water from my garden irrigation as it did pre-drought, I now am noticing that various branches are showing needle die-back. Can you tell me what's wrong? Is it the drought or something else affecting the tree? And if it's something else, what is it and what should I be doing to correct it and bring back the trees to full health?
We have completed our research. The symptoms are consistent with the types of water stress we are seeing on redwoods in the central parts of the county where redwoods are not well-adapted. Under the microscope, there also appeared to be some fungus, but not the aggressive type that would cause a serious problem in your trees. More likely the fungus, in an opportunistic way, came into the needles that were already dying from the drought stress. No treatment is advised or necessary, other than good cultural care of the trees.
The best course of action is to follow the advice you received while visiting us last week: making sure that you water the trees out at the dripline and beyond during the warm, dry summer and fall months prior to the rainy season. Avoid watering near the trunk which can predispose the trees to rot. Redwood trees will compete with each other if planted closer that 7 feet apart, increasing their water needs. Water stressed trees should not be fertilized. As long as the needles are green and growing during the spring and summer, fertilizer is probably not needed.
General Information on redwood trees in the garden can be found at this University of California website http://ipm.ucanr.edu/PMG/GARDEN/PLANTS/redwood.html.
Also, as noted above, during the drought, the MGCC Help Desk has fielded many questions and concerns about redwood trees. A previous blog responded to many of your and others' concerns, especially with advice on irrigation, at http://ccmg.ucanr.edu/HortCoCo/?blogpost=19256&blogasset=12496. Your perusal of the advice and recommendations should help you determine the necessary steps to make your redwood trees healthy again.
I hope that your trees will become healthier ithis spring after all this good rain we are having along with the possibility of supplemental irrigation over the non-rain periods. Please let us know if you have any more questions.
Help Desk of the UC Master Gardener Program of Contra Costa County (JL)
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
MGCC Help Desk Request:I am located in Central County. I am having issues with my lemon tree. I have attached some photos. I was hoping you could give me some advice.
I have never sprayed pesticides. I am hoping for a more organic solution to the issues. I know it might not be possible.
I have not fertilized it this year. It is on our sprinkler system so it gets water daily. Some of the leafs have spiderweb looking substance under the leafs. Some leafs are yellow. I have also noticed the spikes are very large. Thank you so much for your help.
MGCC Help Desk Response: Thank you for contacting UC Master Gardener Program with your lemon tree questions and for sending the photos. The symptoms you are seeing could be the result of various minor problems that occur on citrus. The curled leaves show signs of citrus leaf miner. Citrus leaf miners are moth larvae that create shallow tunnels in young leaves. They can distort the leaves but are generally not harmful to the tree. You are probably seeing the end result of leaf miner damage that was done previously. For more information on citrus leaf miners, see: http://ipm.ucanr.edu/PMG/PESTNOTES/pn74137.html.
We are not sure about the spiderweb type substance. It could be from an insect, e.g., whiteflies, but if so you should also find sticky areas on the leaves. Also, any pictures of the insect would be helpful. It is also possible that there are spiders on your tree. If that is the case, I would not worry. If you want the spider identified, see if you can get a photo and we will try to identify it.
The fruits look like they may have been damaged by the thorns which you indicated are very large. That would happen if the fruits were rubbing against the thorns. Is that possible? If not, another possibility would be herbicide damage. Is it possible that herbicides were used anywhere near the citrus tree? Even your neighbors? Make sure you remove the damaged fruits from the tree before we have any more rain. The damaged areas provide an opening for fungi and other diseases to get into the tree. Also, large thorns might indicate that the branch is a juvenile branch or is coming from below the graft, the "bump" near the bottom of the trunk. If from below the graft, you should consider removing that branch as it probably will not produce edible fruit.
The spots on the leaves may be from a fungus. The fungus may be the result of the watering, especially if the sprinkler system is putting water on the leaves. Make sure that the sprinkler is set low and also make sure that the sprinklers are not dampening the tree trunk. Wet tree trunks can lead to root or crown rot from fungus growing around the roots and crown (where the roots and trunk meet). Root and crown rots are serious diseases that are difficult to treat and can ultimately kill the tree.
The daily sprinkling may also be causing other problems for the overall health of your tree. Daily watering might not be supplying the citrus with enough water. Citrus, like most trees, do best with less frequent, and deep watering to promote stronger roots. To give you an example of how infrequent the watering should be, watering in the heat of summer should be done about every seven to ten days. This would be for citrus planted in the ground and with several inches of mulch under the tree out to drip line. In a pot you would need more frequent watering as they dry out faster. If other plants on your irrigation system need frequent watering, you should consider setting up a separate irrigation system on a different timer for the lemon. For more information on watering citrus, see: http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/CULTURAL/citruswatering.html.
You mentioned that you had not fertilized the tree this year. Yellow leaves are a common sign of a lack of nitrogen. Citrus trees require regular fertilization, especially with nitrogen. The fertilizer should be applied in January or February (prior to bloom) with a second application in May and perhaps a third in June. This link has more information on fertilizing citrus: http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/CULTURAL/citfertilization.html.
Finally, I thought that you might be interested in this general write-up on growing citrus in Contra Costa County: http://ucanr.edu/blogs/slomggarden/blogfiles/4260.pdf
Please let us know if you have any remaining questions. You are also welcome to bring plant samples into our office if you want more information. We are open Monday to Thursday, 9am to 12 noon.
Good luck with your lemon tree..
Help Desk of the UC Master Gardener Program of Contra Costa County (ECS)
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
Help Desk Response: Thank you for contacting the Help Desk with your questions and concerns about your Bush Anemone plant with yellowing leaves.
Once established, this is a very hardy low-water-use plant, but even these varieties need extra water usually for the first several years while becoming established. However, yellow leaves can be a symptom or either under or over-watering. You mentioned that there is only one one-gallon dripper for 40 minutes a week, which would give the plant less than one gallon a week. Even for a young drought-resistant plant, this may not be enough, especially since it was planted this spring spring and in sandy soil. Also, one drip emitter would only be watering one side of the root ball. You can check on the moisture in the root area by carefully digging down beside the plant with a trowel or your hand, to feel for moisture, or if you have a soil moisture meter that can also be used. When you water, you want to wet the whole of the root ball and then let it dry out between waterings. If you want to continue to use drip, a circle of inline emitter hose around the plant or at least 2 emitters on opposite sides of the root ball would provide more even moisture than a single emitter.
http://ucanr.edu/sites/scmg/ Plant_of_the_Month/ Carpenteria_californica/.
The paragraph on Cultivation provides some good advice on getting your Bush Anemone back in good health and watering appropriately for the first several years. (The pictures in this blog post were also copied from the Sonoma County Master Gardener article in the link.)
I hope this is helpful, and that your plant will do well.
Follow-up response from the client: Thanks so much for this information. I have mostly drought tolerant plants but I always find that first year or two a big question mark. I have a newish lavendar that seems to be thriving with no water at all - and then this which seems to need more. And I love this plant when grown, so I don't want to lose it! I'll give it more water until the rains (hopefully) begin.
Help Desk of the UC Master Gardener Program of Contra Costa County (SMW)
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/).