Nursery and Floriculture Alliance
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Nursery and Floriculture Alliance

From the UC Blogosphere...

Can I have a Glass of Water? Please, Please, Pretty Please? No! Now Go to Bed: Tough Love for Your Plants During Drought

There is an emotional connection to our plants. We plant them, feed them, water them, clean-up after them and worry about their growth and development - sometimes it seems a lot like what we do for our children or our pets, although to a lesser degree.  There is definitely an investment of time and resources that goes into gardening.

It is tempting to pamper our plants through frequent fertilizing and watering to ensure that they grow big and lush.  It understandably gives us a lot of pleasure and sense of accomplishment to see our plants thrive and bloom, or produce a bounty of fresh juicy fruit and vegetables. But, with a drought situation, now is not the time to pamper your plants. Now, is the time for tough love.  Your plants might not like it much.  They might become "petulant" by withholding their lushness, not flowering like before or not producing as much. But, they will survive.

Most of us unknowingly over-irrigate our plants, so its ok to reduce the water you give them.  In fact, the amount of water given to plants can often be reduced by 20-40%.  Most established landscape trees, shrubs, and groundcovers, regardless of the species planted, perform acceptably well with 20-40% less irrigation than they are typically given.

To reduce irrigation with the least harm to your plants, water infrequently and deeply.  Do this by increasing irrigation runtimes and extending the number of days between irrigation events. I know this seems contrary to the idea that you should reduce the irrigation runtime and keep the same frequent irrigation interval, but this will work.

Schedule slightly longer irrigation runtimes so that the entire root zone of plants is rewetted at each irrigation; then gradually increase the interval between irrigation runtimes over a few weeks. This practice will allow you to save water while allowing your plants to adjust to a new watering regiment.  After extending the interval between irrigations, the water budgeting or seasonal adjust feature found on many sprinkler controllers can be used to fine tune runtimes and achieve optimum water conservation.

When watering, consider the root systems of your trees, plants, shrubs and lawns:

  • Tall fescue lawns normally have roots 6 to 12 inches deep
  • Bermudagrass and other warm season grasses are normally at least 12 inches deep
  • Trees, shrubs, and groundcovers are normally found within 12 to 24 inches of the soil surface
  • Vegetables vary in depth from 6 to 48 inches (a chart that shows the root depths is linked below for you)

In order to fully wet the soil without creating runoff or puddling of water, it will usually require scheduling 2 to 4 relatively short irrigation cycles of 5 to 15 minutes on each irrigation day, depending on slope, soil type, output of the irrigation system, and how much water is needed.  Splitting up the watering like this give the water a chance to really soak into the soil instead of just running off the dry surface.

Adjust the runtimes in your irrigation controller every month to account for changes in the average weather conditions.  This alone can reduce landscape water use by up to 10%.

It is important to gradually reduce the water over a few to several weeks so the plants can adjust to less water.

Try to irrigate during the very early morning hours (between 2:00 am and 6:00 am) because evaporation is lower and usually there is little, or no, wind to disrupt the pattern of sprinklers during these hours if you are watering lawns.  In addition, water pressure is a little better for irrigation systems during this time.

Night time watering in dryer areas does not normally cause greater incidence of plant disease because the humidity is relatively low.  And, contrary to common belief, midday irrigation does not harm plants.  However, It isn't effective in conserving water.

To find out how deep the water is going into the soil, take a long screwdriver (or similarly shaped tool or soil probe) and probe the soil in several spots an hour or so after an irrigation. The depth that the screwdriver or tool can be easily pushed into the soil is the depth that the water has penetrated. If deeper wetting is needed to wet plant roots, then additional irrigation cycles are needed. If the soil is wet beyond plant roots, then the runtime should be reduced.

Checking the soil moisture each day during drought - or really hot, dry days - with this technique and watching the plants for signs of wilt or water stress will enable you to see how long it takes for soil to dry to the point where water must be replaced. This is the maximum interval between irrigations for the current season.  Ideally, irrigation is applied just prior to the onset of plant stress, so schedule irrigation about one day shorter than the maximum interval.

Note: Established small shrubs or groundcover are those that have been in the ground for a period of one year or more. A tree or larger shrub must be in the ground for at least 3 years to be considered established.

To determine the root depth of your herbs & vegetables, go to: Herbs & Vegetables Root Depth Chart


Posted on Friday, July 31, 2015 at 6:00 AM

How I Converted My Yards to Drought-Tolerant Plants and Shrubs, Part 1

This segment will discuss remaking our back yard.  We also took on the project of replacing our front lawn once the backyard renovation was mostly complete, but more on that in the next post! 

In late 1996, my husband, two children, and I moved from Montana to San Ramon. In Montana, we had tried to make a living in a rural setting, but “You can't eat the scenery", I learned too late.  When we moved to San Ramon, for a variety of reasons, we needed to find an empty house read for immediate possession. The house we bought came with a big backyard pool. We certainly enjoyed having the pool for many years, but once the kids were out of the house, we didn't use it much. The solar panels used to heat the water meant the pool was only hot enough to swim in from mid-May through September. While the maintenance costs weren't astronomical, we spent plenty to keep it in good condition. Other swim venues were very close at hand – San Ramon's huge swim complex is right over the creek at California High School – and I belonged to 24 Hour Fitness so I could swim there in an indoor pool any time of day.

Deconstruction of Pool Begins
In 2013, we got a couple of bids to repair the pool and decking, and found out it would cost more to fix it than to take it out completely. We decided to take out the pool.  Beginning in December 2013, our contractor began work to completely remove all evidence of a pool. Because we got rid of the pool all together, we received a $13,000 reduction in our property taxes. In other words, we pretty much paid ourselves back for turning the backyard into a living space for families.

At the time of the pool's deconstruction (as I like to call it) I was in the midst of my Master Gardener training through Contra Costa County and University of California County Extension Program (UCCE).

I knew from my MG training I wanted to have raised vegetable beds and to plant easy-care plants and shrubs. Since we live near the entire spectrum of K-12 schools, we also decided to add lawn for salability purposes. Many parents would want to have a play space for their children.

Our house is a typical tri-level suburban house that sits on a 70' x 100' sf. lot. In my Soils class, I learned our house sits on clay soil with no nutritive value, suitable only for supporting a 1500 sf. house. I would have to bring in lots of good stuff if I expected anything to grow! Because of San Ramon permit requirements, we had to replace our pool, and concrete decking with the same type of soil our house sits on. We had a soils engineer overseeing the placement and compaction of soil trucked in from the East Bay Hills. Only the final 12 inches could be ‘living' soil we could plant ornamentals and trees in. We were assured the soil was decent, though we might want to add compost and other amendments to attract worms and the like.

Filling the Pool up with Filf Dirt
As you can see from the pictures, the pool and required concrete decking really did take up 80% of the arable yard. (I love the one of the diving board to nowhere!) Once this contractor was finished, we needed another contractor to bring in ‘good' soil for our two 8' x 3' raised beds, the hillside where the giant date palm tree and a large cypress bush reside, and the rest of the yard that did not need fill that met permit requirements. Before this work was done, Bill spent countless hours building a paver patio and yards of French drains to carry water away from our house. Handy husband Bill also put the two raised beds together. For good measure, he tacked on landscape wire to the bottom to keep rodents out.

Pool filled in and beginning of Backyard Grading
Our landscape contractor brought in ‘good' soil and compost, created the irrigation system for the lawn and the raised beds, and laid warm season fescue grass sod. He moved agapanthus plants and removed some palm trees that we did not want (though one grouping has since grown back and it is easier to keep them now). Much of the perimeter's plantings pre-existed this renovation work. Lined against the house, three types of geraniums (that I have propagated more than once), and agapanthus (that I had moved from elsewhere) have thrived with very little direct sun. Both of these plants are extremely low maintenance and are rarely watered. You can get cuttings or corms from friends that will fill in your planting area in less than a year, guaranteed! Along this same wall, I took out a bed of geraniums and replaced them with half a dozen nearly dead Abutilon plants in 4” pots. Happily, for me, all but one of these plants are flourishing and have put out many yellow, pink and red colored blossoms in abundance! Oleander bushes cover another side along a neighbor's fence.

The hillside at the back of the property was covered with mulch, which was easy to live with and easy to replenish as necessary. The landscaper first moved the mulch to the level surface around the grass and the raised beds, and then added soil to the hillside. I have since added a lime tree, two miniature agapanthus plants, and three pittosporum bushes to the hillside, and creeping rosemary and white yarrow against the date palm behind a stone wall barrier. The fourth side, along our other neighbor's fence, now has agapanthus, two rhododendrons someone gave me, a transplanted ornamental onion set, and in the corner, a leafy grape plant that so far does not bear fruit but turns a lovely red on the fall. My neighbor's vinca minor has been creeping into that corner as well, and I am doing my best to encourage it.

Backyard leveled out

My two planter boxes hold a mishmash of plants. Last year's crop of heirloom tomatoes, tomatillos, various peppers and artichokes were a wash-out due to the lack of enough hours of sun. Now I am using the beds as a nursery of sorts, to grow small plants and seedlings for re-planting elsewhere. I also have one artichoke that is blooming, and some red onions and garlic that I expect will make it and be edible 

Finished backyard

I have barely touched the surface of my efforts, but I am happy to know that every plant is there because of me. It's okay if some die, because I know where I can get more. I have to admit I did not enjoy the work initially because I had so little confidence. I thought I had a ‘black thumb.' Now I know that is not true. Although I have a long way to go to become a ‘master' master gardener, I know I can accomplish what I set my mind to achieve. And boy, oh boy, is that a great feeling!

Next chapter: My front yard conversion: a lot more work that continues to this day!

Posted on Wednesday, July 29, 2015 at 1:02 AM

Grapes Not Looking Too Good?

Client's Question and Request:
I'm in central county and growing Zinfindel Grapes in my backyard garden. The vines are now several years old and producing fruit this year. The grape leaves have now developed “blotches” and the grapes look “cloudy” and not very healthy. What's the problem and what can I do about it? The pictures below show the leaf damage and what the grape bunches look like.

Zinfandel Grape leaves impacted
earlier by powdery mildew
Zinfandel Grapes impacted by
Powdery Mildew

MGCC Help Desk Response and Advice:
Based on the grape samples and the photos you provided, the problem with the grapes appears to be powdery mildew.

Powdery mildew is a common fungal disease on grapes. It first shows up as faint white powder on the grapes but later can progress to cause brown russeting on the developing grapes. That russeting was somewhat apparent on the grape samples you brought in. Affected fruit cannot ripen normally and may crack as it grows.

Shady conditions and lack of good air circulation favors the development of the disease on grapes. When the vines are pruned iduring dormancy so that shoots are positioned in the next growing season, try to prune so that the plants will allow exposure of the developing fruit to sunlight and good air circulation. Avoid overhead watering of the vines which can spread the fungal spores to new locations.

Next growing season, watch closely for the appearance of powdery mildew. Early signs of a developing problem include young emerging leaves being deformed or showing a puckered condition. Prune out such areas as soon as they appear and it may help to prevent new infections.

If you lose a large percentage of the grapes this season, you may also want to consider the use of fungicides to prevent a recurrence next year. Take a close look at this UC website which gives detailed information about different types of fungicide that can be used and includes directions on how and when they should be applied:

We hope this information is helpful. You're welcome to contact us again with any further questions

Help Desk of the Master Gardeners of Contra Costa

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:, or on the web at

Posted on Monday, July 27, 2015 at 12:10 AM

Native Plants



Native Plants 

By Nancy Hartwick  UCCE Master Gardener


What are the advantages of landscaping with California native plants?  Mary, Atascadero


 Native plants can be quite liberating. They free the gardener of the work and expense of fertilizing and watering. Natives need no fertilizer because they work in partnership with bacteria in the soil called mycorrhizae. These partners help the plants absorb water and nutrients and fix nitrogen in the roots of some species.

Watering is required when the plants are first put in the ground. But once they are established, usually after the first year, little or no water is needed, except in times of extreme drought. Some species of plants, such as Ceanothus and Arbutus will weaken and die if overwatered.

Coastal California has a Mediterranean climate, with normal rainfall occurring from fall through spring. Summers are dry and watering established natives at this time is a definite no-no.

The gardener will have little or no use for insecticide as these plants are adapted to live with our naturally occurring insects. Forgoing insecticide may allow more beneficial insects, such as bees and butterflies to thrive in the native garden.

Soil amendments are also not recommended. Rather, choose plants according to the type of soil you have, be it sand, sandy loam or clay. You may find several types of soil on different parts of your property. So work with it, rather than against it.

Also, study the needs of the plants you want with regard to environmental factors such as sun exposure, drainage and wind. Plants   that do well in the north part of the county may not thrive at the beach or in south county. Furthermore, what grows in your front yard may not thrive in the back yard due to differing microclimate conditions. 

Your garden may look a little sparse in the beginning, as many of the plants are slow starters. But make note of the estimated size of the mature plants, and plan carefully to avoid crowding.

For an extensive list and descriptions of California native plants, visit  There you'll find information about the plants as well as planting and maintaining your native garden.

Posted on Sunday, July 26, 2015 at 4:31 PM

Daily Life For Master Gardeners

Let's Talk About the Weather

By Andrea Peck


After last week's impromptu rain shower I thought that I would address the issue of excessive rain.

Some may find that hilarious. I mean, one downpour and we're running around with silly grins on our faces or getting hit by lightning. It's California, Land of the Perfect Weather, what is there to even talk about?

Look at us. Just as we started to figure out the details of utilizing our greywater we are besieged by record breaking, monsoon-like rain. The most shocking thing, besides the amount of rainfall, was the temperature. I checked my own thermometer and it was 82°F inside my house. Should I be outside sweeping in my bathing suit? Yes. By all means. Did I mention it was midnight?

But, I need to clarify that this was the second night of the two-day siege. The first night was a horse of a different color. It all started with a thunderous clap at around 1:30 a.m. The sound, a booming explosive crash led my mind to one thought-- clearly we have been invaded and the house is falling apart. I leapt from the bed and ran to the room of all things disruptive—the living room. My legs traveled with a quickness that I can only say was half-flying. The dogs, who were second on the scene, looked at me somewhat quizzically. Their fur covered noggins were either amazed at my superior speed or embarrassed by me. They are laid-back California dogs after all.

Quickly realizing the source of the fracas –thunder and lightning-- I headed back to bed. Not long thereafter, a drizzling rain started. This turned into a moderate fall and then I realized I had better get up again and check our drains. Our home is located in a particularly low spot that in 1964, when the home was built, probably caused little problems for the owners. However, as time wound on, further development created runoff that leads through many streets and passes along the sides of my home. The owners at one time had to create sizeable drainage that cuts along the length of the property. “The drains” as we call them are four feet wide and about 8 inches deep. In a heavy storm they fill to capacity and run like a little river. It is a pretty exciting exhibition. Problems can easily arise if objects interfere with this flow.

I should have known better. Call me complacent but we have become accustomed to this drought. My drains have become storage for the detritus that explodes from the confines of my home. Well, punishment comes in the wee hours of the morning when lightening threatens your life and water threatens your home. Nevertheless, I am happy that this onslaught besieged us. Now, we have no excuse. The forecast this winter is an El Nino which brings a lot of rain and warmer temperatures. I have seen the temperatures. I have seen the rain. Now I am a believer. Time to get ready.

A few things to think about:

  1. Start at your roof. Make sure the roof is in good condition. If we do receive wet weather this year it will not be fun trying to patch the roof in the rain.  Move to your rain gutters. I'm sad to say this is something that we have neglected in our home. What a shame! This year I vow to have existing gutters cleaned and inspected. I would love to get rain barrels all around. Don't forget downspouts. There are great extension pieces that you can connect to the end of your downspout and direct the water to plants or lawn. Divert runoff from concrete, roads and your front door. My lovely neighbors had a problem with their garage flooding until some smartie found a leak in the roof gutter directly over the garage. Problem fixed! So easy.


  1. Clear brush and prune large plants and trees. Excessive amounts of water can weaken the root of susceptible trees and bushes causing them to fall over. If you live in an area like I do where water moves from one place to another it may behoove you to keep those areas clean and free from excess leaves, twigs and skateboards in order to prevent a buildup of water


  1.  For those who live in soggy spots it is a good idea to have sandbags ready. Make sure that they are accessible and that you can lift them quickly and easily without injuring yourself. One year my husband filled the bags and I could barely lift the things. After that I swore that I would fill the bags myself. A lighter bag is better than a bag you cannot lift. Also, sandbag material (the plastic bags) tends to degrade very quickly so make sure you won't be lifting a bag that is ready to fall apart. If you have one area that consistently floods, consider purchasing a little submersible pump.


  1. In case of emergency, have car keys, belongings, and medication handy. Make a plan with family members. If you have pets, add food, water and bedding, including pet crates, to your list. But, please don't risk your life—while discussing the threat of fire and creating a plan with my two kids, my son insisted that he would rescue the gecko. And the gecko's food. It took quite a bit of convincing to dissuade him from this plan of action. Keep important papers handy. We have our important papers in a portable file box. Of course, knowing myself as I do, I will forget that box. Nevertheless, it is there and ready to go.


  1. Friends. Figure out who they are. I would put this at the top of the list because in my recent experiences I discovered quite by chance how important reliable social connections are. Know your neighbors, particularly the ones who are home, able-bodied and helpful. They may just save your life one day.


  1. Finally, do not underestimate the power of water. It does not take much water (two feet or less) to move your car. Remember water and electricity do not mix. Never go out in a lightning storm. According to our local expert John Lindsey, many are killed and injured each year due to lightning strikes. It is not the stuff of myths. In fact, if you haven't heard, a white truck was struck by lightning in the last storm here on the Central Coast.


Note: I realized I have not included instructions on caring for your poinsettia! Here are the recommendations for June and July:

During June you should have moved the pot outside in a shaded area and continue with water and fertilizer. (You can use a water soluble fertilizer).

During July, pinch an inch from each stem. Continue care as in June.

If you have not changed pots you still have time to do so. Use a soilless mix and a pot that is 4 inches larger in diameter than the existing pot.

For the full post with details go to this link:

Posted on Sunday, July 26, 2015 at 4:25 PM

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