Monthly Archives: July 2015

California drought, drought tolerant gardens, dry river bed, erosion control, garden design, grasses, sustainable gardening

Dry River Beds – Beautiful & Beneficial

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Dry river bed down a steep slope

With so many people replacing their thirsty lawns with low water-use plants, I?m getting lots of requests for ideas about what to do with all that empty space. The sky?s the limit when you have a blank slate. Let me get you started.

If your old lawn was in the front you might consider putting in a sitting area for a couple of chairs and a bistro table. Use simple crushed gravel or more formal flagstone underfoot and surround the space with a low seat wall to add a bit of privacy.

Adding a dry river bed is another good solution. A dry river bed can slow runoff, spread it out and sink it back into the soil. Connected to a downspout they keep even more rainfall on your own property. If we get the El Nino storms that are predicted this will be a welcome addition to your landscape.

A dry river bed is a rock-lined swale that uses rounded river rock in addition to vegetation to allow

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Dry river bed with grasses and deer resistant oleander

runoff to soak into the ground. Make sure there is a 2% slope from beginning to end to ensure that water is conveyed away from your house to the desired location. Non-woven geotextile fabric is often used underneath the rock.

You can create a depression or rain garden at the end of your dry river bed and plant it with plants that tolerate wet feet in the winter. Both a dry river bed and a rain garden allow water to sink back into the ground. The plants remove pollutants from the runoff from roofs or other impervious surfaces.

A rain garden might be a simple, shallow depression filled with plants that can flourish in both moist and dry conditions. The size and depth will depend on your how much water you need to capture in a winter runoff

Sometimes a dry river bed will receive so much runoff that a dry well or dispersal pit is installed at the end. If you have a high water table or clay soil the water may not always soak in fast enough and an overflow device like this is needed. The goal is to keep water on your own property and not in the street or the neighbors? yard.

There are good looking dry river beds as we?ll as bad looking ones. A quick Google image search will show you what I mean. Your goal is to create something that looks like it belongs right where it is. The plants, the accent rocks, the cobble, the location – all need to work together.

If your property has a natural slope follow the natural terrain if possible. You can install a dry river bed on flat land also by creating a channel for the river bed to follow. Keep in mind that even a dry river bed is more interesting if it is not all visible at once. Soft, flowing curves and bends create a natural look.

Start with the rocks and cobble. Rounded river cobble looks most natural for the creek bed. In nature, water flowing down a river would round off sharp rock edges to produce cobble of different sizes. A river never has just one size of rocks and yours shouldn?t either.

Accent rocks can be any type that you like as long as you get a variety of rock sizes and shapes. Use the larger stones to direct and channel water. Placing rocks on the outside of a curve creates a more natural look.

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Pheasant Tail grass along cobble path

As in all gardens there is always a bit of maintenance to keep things looking and working great. Weeding in the first couple of months while plants become established is important. Replenish mulch as needed until the plants grow in.

Periodically remove leaves that have landed in your river bed and reposition rocks moved by runoff to keep your dry creek bed working for you when you need it. Also don?t start your dry creek bed too close to the foundation of your home if that area is flat. You can direct the water through a drain pipe connected to a downspout to a lower starting spot in your garden.

So whether you are adding a dry river bed to add interest to your lawn-free landscape or to double as catchment for winter storm runoff, make yours look like it?s always been there.

California drought, Stanford University trees, trees, water saving techniques, watering, watering trees

Save Water – Save Trees

I had to do it. I couldn?t resist. Even though I?d vowed not to get any new plants until fall planting season when I saw the one gallon Pride of Madeira just begging for a new home I succumbed to my impulse. I rationalized this plant was on my wish list and will be drought tolerant so I wasn?t being totally irresponsible.

I?ve always wanted an echium fastuosum on my hillside. I admire those huge spires of purple-blue flowers whenever I see them in other gardens. These are tough plants getting by with no summer water once established and the flower spikes are bee magnets. I covered it with a layer of shade cloth for a few days because it was so hot when I planted it. This will help it establish more quickly while the roots take hold in the soil.

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Flame tree on Stanford campus

In your own garden it?s wise to establish a drought to-do list. I?m talking about what plants get your precious water and what to let go.

As we enter another dry year many of our ornamental and fruit trees are dying. Many were watered along with the lawn you have now let go brown. Others might have been surviving on natural rainfall. Whatever the case in your garden don?t let your trees die.

Nature has already killed an estimated 12 million trees in Calif. forests since the drought began four years ago. Most of these have fallen victim to bark beetles that attack trees weakened by drought.

In our own neighborhoods, trees are a long-lived asset. A tree is not something that can be easily replaced. It?s OK to appropriately water trees. Dying trees can be a safety hazard and removing a dead tree is expensive.

It takes years to grow a tree to mature size. Save and use shower and cooking water to help them out. Maybe it?s time to install an simple laundry-to-landscape system to water your landscape trees. Or set up a separate drip or soaker hose for your trees and give them a good deep drink at least once or twice a month. And remember that the tree?s feeder roots are not at the base of the trunk but out at the drip line and a little beyond.

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Laurel tree on Stanford campus

A rule of thumb for determining when to irrigate is when 50% of the water has been depleted from the soil in the plants? root zone. This allows a buffer of water in the soil in case the weather suddenly turns hot and windy and applies to trees, shrubs and perennials.

Sandy soils hold less water than clay soils and must be irrigated more frequently. A common misconception is that it takes more water to grow plants in sandy soil than in clay soil. Actually the total amount required for the whole year is the same for both soil types. The amount of sunlight, wind, temperature and humidity control how much water a plants needs – the soil is only the reservoir.

To check the water content in the soil dig 8-16 inches down into the soil with a trowel, shovel or soil tube and feel the soil. At about 50% available water:
* Course soil appears almost dry and forms a ball that does not hold shape.
* Loamy soil forms a dark ball that is somewhat moldable and can form a weak ribbon when squeezed
between the finders.
* Clayey soil forms a good, dark ball and makes a ribbon an inch or so long and slightly sticky.

If you are planning to plant some new trees this fall, be sure they are drought tolerant natives or low water use non-natives. There are many nice specimens to choose from. And don?t skimp on the mulch.

It?s important to maintain our existing tree canopy and plant for the future. Even in times of drought, no especially in drought, planting and stewardship of trees is critical. Not just for their future but for ours as well.

California Native Plants, colorful foliage, compact shrubs, drought tolerant gardens, drought tolerant plants, espalier plants, flowering shrubs, Flowering trees, garden design, landscape design, low water use plants, screening plants

Screen the Neighbors with Low Water-Use Plants

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ribes sanguineum

We all enjoy privacy around our homes. Even if you?re best friends with your neighbor you don?t always want to wave at them each morning in your robe. Whether you have a property tucked way back in the forest with a next door neighbor that looks right down on your deck or a postage stamp size lot that could be an jewel if you just had a screen between you and the next property, there are techniques designers use to make your home a private oasis.

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azara microphylla

Narrow spaces can be challenging when you need to screen the house next door. There?s not room for a big, evergreen tree or hedge to solve the problem. One way is to use plants that can be espaliered against a fence or trellis. Some plants like azara microphylla naturally grow flat without much coaxing on your part. This small dainty tree is fast growing and reaches 15-25 ft tall. The yellow flower clusters will fill your garden with the scent of white chocolate in late winter. They are ideal between structures. I?ve used the variegated version to screen a shower and it?s working great.

Another small tree, the Compact Carolina cherry laurel can be espaliered also in a narrow space if needed. It grows 10 ft tall but that may be all you need to screen the neighbor. They are drought tolerant once established, deer resistant and the perfect host for birds, bees and butterflies. The leaves smell like cherries when crushed which gives this plant it?s common name.

A dwarf tree that also works nicely in this situation is a Southern magnolia called Little Gem. Naturally a very compact narrow tree it grows to 20-30 ft tall but only 10-15 ft wide. It can be trained as an espalier against a wall or fence and the sweetly scented flowers will fill your garden with fragrance.

Other small trees that make a good screen are purple hopseed, and leptospermum ?Dark Shadows?. Both have beautiful burgundy foliage. California natives that can be espaliered against a fence include Santa Cruz Island ironwood, Western redbud, mountain mahogany, toyon, pink flowering currant, Oregon grape and spicebush.

If you have a wider space to grow screening plants, one of my favorites is Pacific wax myrtle. This California native grows quickly to 30 ft tall with glossy, rich forest green leaves. Its dense branches make a nice visual and noise screen for just about anything or anybody. I?ve never used the subtle spicy leaves for flavoring sauces but I might try it next time a recipe calls for bay leaves. Best of all the fragrant waxy purplish brown fruits attract many kinds of birds.

Italian buckthorn is another evergreen screening shrub to consider. It reaches about 15 feet tall by 6-8 ft wide and has low water needs. It can grow 2-3 feet in its first few years making a quick screen. There?s a variegated version with stunning foliage that looks awesome mixed with the green variety in a hedge.

Another favorite hedge plant, the California coffeeberry grows 6-8 feet tall and gets by with very little summer water once established. Birds love the berries.

I also like osmanthus fragrans for a screen with a sweet scent and pittosporum ?Marjorie Channon? or ?Silver Sheen? with their showy variegated foliage.

If it?s just not practical to screen the perimeter of your property redirect your line of sight to keep attention focused on the garden instead of on the landscape beyond. A recirculating fountain as simple as an urn spilling onto cobbles at the base can disguise noise and become the focal point. There are lots of ways to add privacy to your home.