UC Master Gardeners, Santa Clara County, CA
University of California
UC Master Gardeners, Santa Clara County, CA

Waterwise

Garden Help > Monthly Tips

Even in years with plentiful winter rainfall, our summers in Santa Clara County will always be dry. Planning your landscaping and gardens for our summer dry conditions will put you ahead of the game for future droughts and water restrictions. Here are some useful tips and links for homeowners and gardeners who want to manage their garden and landscape in a responsible, waterwise manner.

Waterwise Tips

Ailing Ornamental Trees

If you have an ailing tree, here are some questions you can ask yourself to begin diagnosing the problem: is the entire canopy of the tree affected? If the answer is yes, you can reasonably guess that something is wrong below the soil. A lack of nutrients (refer to the UC Pest Note on Mineral Deficiencies) will likely cause the leaves to either die (necrosis) or lose color (chlorosis). Too much or too little water will also cause foliage problems (See UC Pest Note on Poor Water Management, Poor Drainage).

If only parts of the tree are affected, it is likely your problem is above ground. Is there a pattern to the distress? You can rule out or suspect sunscald by determining which side of the tree faces the harshest sun (UC Pest Note on Sunburn).

What kind of tree is it? Is there new growth? If there is, that’s a great sign that a single event rather than an ongoing problem distressed your tree. The UC IPM website will direct you to species-specific pests and disorders to begin diagnosing your tree's ailments.

Aloes

Aloe Vera is just one of 500 species in the Aloe genus. Most are native to Africa and parts of the Middle East. They generally grow in a rosette pattern and store water in thick fleshy leaves and stems. Some are dangerously spiky at the tips. Flowers are usually brightly colored and grow on spikes. Aloes are easy to grow in our climate and also make good indoor plants. They are most often propagated from cuttings or by dividing the “pups” from the parent plants. Be careful not to overwater these succulents, especially if they are outdoors during frost season.
 
More Information: Aloe Cultivation

Arboretum All-Stars

Arboretum All Stars logoThis is the best tool for landscape planning available to Northern California gardeners! The UC Davis Arboretum All-Stars are plants found to be especially successful in California. The website covers essential planting basics for landscape planning, including easy-to-grow plants with low-water needs, fewer pest problems, and other outstanding qualities. As an added bonus, most are California natives that attract beneficial wildlife.

Container Color Choice

If you are growing plants in containers, keep in mind that light colors do a better job at reflecting the sun. This helps keep the soil from drying out too quickly and reduces the chances of the roots burning. If you already have dark pots, consider painting them a lighter color, or be especially careful about watering.

Drip Irrigation

Low volume drip irrigation system
Low volume drip irrigation system
Consider various forms of irrigation conversion! Irrigation systems, especially drip and micro-sprinklers, have drastically improved over the last few years. For example, there are kits that convert pop-up sprinkler heads to low-flow systems. The conversion kits include a pressure regulator to control changes in pressure and a filter to improve water quality. Water usage is reduced through better water management, control of distribution and less loss from evaporation. Other advantages include :

- Water is placed more accurately and efficiently in the root zone, it is applied at a slow rate that reduces loss from runoff.
- Dry soil between plants allows you to work in the garden between irrigating.

The key to success is watering long enough to supply adequate water to the root zone. Inappropriate watering commonly damages landscape plants. As with any irrigation system, they are efficient only when soil around the plants being irrigated is regularly monitored for proper moisture levels (Reference: UC Pest Note Poor Water Management, Poor Drainage).

Drought or Disease

Drought stress on magnolia (Magnolia), Missouri Botanical Garden
It can be hard to tell if a stressed plant is suffering from a disease or a lack of water due to drought. Water stress causes plants to lose their leaves, shrivel and droop, with split bark and brown branch tips soon to follow. These symptoms could be mistaken for diseases that attack the plant’s roots and vascular system. But it’s also true that water-stressed plants can be more susceptible to pathogens due to their weakened state. Check soil moisture for your ailing plant, and if it’s dry, try irrigating the plant. If it doesn’t respond, contact the our Help Desk for further assistance.

More Information: Drought or Disease

Drought Tip - Laundry to Landscape Irrigation

A laundry to landscape system is an easy way to save water in times of drought. It can be installed easily at a low cost to send rinse water from clothes washers directly to the landscape. 

Suitable plants include fruit and ornamental trees, shrubs, and ornamental annuals. It’s not applicable where the water would come in direct contact with fruits or vegetables. 

More information: Laundry-to-Landscape Graywater System

 

Drought Tip - Lawns

Conserving water during a declared drought emergency, by Laura Monczynski
This landscaping feature—imported long ago from rainy, foggy England—does not translate well to a semi-desert with frequent droughts. Lawns demand a huge investment of water, money, time, work, equipment, and fertilizers and other chemicals. According to Scientific American, U.S. lawns require the equivalent of 200 gallons of drinking water per person per day. Many people are joining the "lose the lawn" movement, and UC Davis offers several plans and examples to help you get started on a yard design more appropriate for our climate. Valley Water offers rebates and guidance for lawn replacement. If your family uses your lawn and you want to maintain it this summer, follow the irrigation regulations of your local water company and aim for survival rather than a lush green carpet. A lawn that looks light green or brown will often be dormant (not dead) and will perk up with the winter rains; the roots can survive much longer than the blades above ground. Keep it mowed in the meantime so that weeds don’t go to seed and take over. Concrete and synthetic (plastic) turf do not benefit the environment other than not using much water.

More information: Drought Resources 

Drought Tip - No Fertilizer

No fertilizer
Fertilizing your lawn and landscape encourages lush new growth. That’s usually what we want, but not during a drought. That new growth requires extra water to support it. Plus, if a plant is already drought-stressed, fertilizer may cause it more stress by stimulating growth that can’t be supported with limited water. In other cases, plants may slow or shut down growth under drought stress to conserve resources and will not use fertilizer.

More information: Skip fertilizing 

Drought Tip - Trees Come First during Drought

Tree with irrigation ring by Laura Lukes-2
With no end to the drought in sight and water restrictions in place, Santa Clara County residents must make some tough landscaping choices right now – namely which plants in our yards should receive our limited supply of water? The answer is trees. Because trees take years to grow, they aren’t as easily replaced as other plants. Besides that, trees provide shade critical to cooling our homes while releasing oxygen and reducing energy use. Using a hose or soaker hose, slowly trickle water in a large circle under the canopy of the tree (but not right at the trunk). Deep watering for two hours once every few weeks will keep established trees alive.
 
More information: Tips to Keep Trees Alive
 

Echeveria

It's easy to have color in your yard without using a lot of water. Instead of planting thirsty annuals, consider some of the many types of succulents. Echeveria does well in containers or in the ground. Plant them in well-drained soil and allow the soil to dry between waterings. They aren't particular about sun or shade, although some can be a little sensitive to full afternoon summer sun.

Fall Irrigation

You can still expect some warm weather during October, so keep watering the garden until the fall and winter rains begin. As temperatures drop, less water is needed for plants.

Check your soil periodically by digging gently into the soil next to the root, about 6 inches down (deeper for bigger plants). If the soil does not hold a shape when squeezed it is too dry; if it continues to hold shape after the pressure is released it is too wet; if the soil has a shape then crumbles quickly, it has the right amount of water.

Hydrozone any new plantings by putting plants with similar water needs together. This helps ensure that less water is wasted and that all plants get the right amount of water.

If you have an automatic watering system, this is a good time to inspect the system for leaks and blockages, check the timer for batteries, and reprogram the system as necessary for cooler weather and rain.

If you don't have an automatic watering system, think about installing one. Many systems are very affordable and easy to install by the home gardener. Take a look at some "smart meters". They are more expensive, but incorporate weather conditions, your location, and your soil into the programming, making them very efficient.

Fertilizing Ornamentals During Drought

One way to manage plants during drought is to reduce the amount of fertilizer used. While plants need nutrients to survive and be healthy, excess fertilizer promotes additional growth, which then demands more water.

Garden Planning in a Drought

Drought tolerant landscapes can be beautiful, UC
Even when we get good winter rains, our summers are dry. So, water-wise garden planning is always a smart choice. We can prioritize the plants with more value, including food production or a long-term investment. If your existing plants are crowded, consider removing some so they don’t compete for water. This is a great time to get rid of any that you don’t really like. Why waste water on them? Don’t add new plants to your landscaping while we remain in a severe drought. Even drought-tolerant plants and California natives need extra water to get established.

More information: Drought: Gardening Tips

 

Going Native

Native shrubs, trees, and flowers are well-adapted to our climate and soil, and support native butterflies and bees and other wildlife. They are drought-tolerant once they are established, but need adequate water for the first year or two to establish a strong root system that will help nourish the plant for years to come. Planting them in the fall gives them time to settle in before being hit by the heat of the summer sun. Consult Water Wise Plants and the California Native Plant Society for more information. 

Lawn Care

Lawn, by Donna Lee
As the weather changes, many of our management techniques have to change. Lawns need more water as the temperature increases and the humidity lowers. But please be sure not to overwater, too much water is being wasted by going below the root zone or running off.  Adjust timers monthly throughout the year. In the warmer months, lawns may need water twice a week. It is not good to water daily. If watering is daily and brief, the roots will stay shallow and susceptible to drying and burning. Be sure to water as early in the morning as possible to avoid evaporation. This also helps reduce fungal diseases by giving the grass time to dry out during the day. Poor watering practices are the main reason for dead and dying areas in lawns and a common source of urban runoff.

Make sure you are mowing to a height appropriate for your type of grass. Mow frequently enough so that only one-third of the leaf is removed at any one time.

Fertilizing is important, even if you are grasscycling, which only provides about 20% of a lawn's fertilizer needs. Grass is all leaf so the primary nutrient needed is nitrogen. Keep on top of weed removal.

Thatch is the layer of living and dead grass material (blades, rhizomes, stolons) that can build up on the surface of the lawn. A thin layer protects the soil surface and shallow roots from drying out from the sun, but a thick layer prevents water from getting through. You can remove dead grass material on the soil surface with a special thatch rake to allows water to reach the roots more easily. 

More Information: The UC Guide to Healthy Lawns

Save Water and Make Your Plants Happier

After your vegetable garden is well established, it's better to water thoroughly once a week rather than giving it a light watering every day. Doing that will encourage a deeper root system which will help the plants tolerate dry weather better. This is also true for fruit trees. For more information visit UC Pest Note on Watering Fruit and Nut Tress.

Tomato blossom end rot

Tomato blossom end rotA brown depression on the bottom of tomatoes is usually blossom end rot (BER). This disorder is related to a calcium deficiency aggravated by irregular watering. Since most soils have adequate calcium, watering is usually the problem. Without regular watering, the calcium in the soil cannot reach the plant. Mulching can help. Water tomatoes regularly. Avoid flooding them so the roots sit in water. For more detailed information about BER please view Managing Blossom-End Rot in Tomatoes and Peppers.

Water Budgeting

We always need to use water wisely. Sometimes it is necessary to stop and think about your landscape and prioritize water use. Trees are a long-term investment, yet mature trees may have extensive root systems enabling them to find enough water on their own. Fruit trees may need watering approximately monthly during the summer in order to produce good fruit. Vegetables should always be given adequate water in order to fulfill their purpose in the garden; otherwise the little bit of water you used will have been wasted if the garden is not feeding you well. It’s helpful to understand that home-grown vegetables use much less water overall than ones purchased at the store. Established flowering shrubs, especially California natives, tend to need less water than annual flowers and maybe a more water-efficient way to have color and beauty in your garden. Lastly, keep the weeds under control so that they don’t rob water from the plants that you actually want.
 
 

Water the Roots, Not the Plants

It's tempting to get the hose out and spray your dry, thirsty plants, but you don't want to waste water. Keep their feet nice and cool, but resist the urge to squirt the leaves unless they need a cleaning (for dust or white fly for instance).

It's a common belief that daytime water on the leaves will burn them. While it's possible, according to scientists—for hairy leafed plants where water droplets are held above the leaf surface—but not very likely. It's more the water will simply evaporate and not do your plants much good and could encourage fungal pathogens if wet overnight.

Watering Hydrophobic Soil

Just as a dry sponge repels water, overly dry soil can do the same thing. This dried out soil is called hydrophobic. Hydrophobic soil can waste a lot of water as water drains away from the plant's root zone.

In pots: learn more about how to re-wet very dry soil on our Watering Hydrophobic Soil page. In the yard: setting sprinklers to run for 5 minutes, waiting for the water to soak in, and then running for a longer time can prevent water loss due to hydrophobic soil.

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