Category Archives: 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.

A Visit with a Plantsman Extraordinaire

upper_patio.1600Spring just wouldn?t be the same without a visit to Doc Hencke?s garden in Scotts Valley. I think of it as a learning experience at his personal arboretum, outdoor laboratory, propagation field trial and stunningly beautiful landscape. At every turn colorful vines bloom high up into the trees he has collected and nurtured from his travels. Richard Hencke is a walking encyclopedia, energetic and funny while sharing his knowledge and stories about each and every plant. Here are just some of the highlights of this year?s visit.

The definition of the word arboretum describes Richard Hencke?s anemone_clematis_vine.1920garden perfectly. It?s a place where an extensive variety or trees, shrubs and herbaceous plants are cultivated for scientific, educational and ornamental purposes and my tour this year started at a tall California native Flannel Bush which he had to rope to the ornamental iron fence after it blew over in that wind storm a month ago. Looked to me that his efforts to save it will be successful and if anybody can it will be Doc Hencke.

Explaining that the soil in this part of his garden is blue hard sub soil and has taken it?s toll on a couple other plants. One of his Eutaxia obovata also called the Bacon and Eggs plant was just going out of bloom but 2 others nearby have suddenly died. Quite the loss as this shrub is one of those plants that really gets your attention when it?s covered with thousands of golden pea-shaped blossoms.

Next on the tour came the straw bale veggie garden. Since the soil in this straw_bale_veggies_Richard.1600sunny spot is also sub par this method of cultivation has been a real success. Richard told me that when the bales were first put in place he watered them thoroughly to start the fermentation process. He used a meat thermometer to check their internal temperature and determine when this process was complete and vegetables would thrive. He then soaked them with liquid organic fertilizer and applied some blood meal to augment nitrogen. His crop of kale, lettuces, spinach, bush beans and cucumbers looked robust and happy.

Always the story teller, Richard pointed out a Cantua, the Sacred Flower of the Andes that he air layered to increase his collection. He laughed when he told me of a trip to Peru and the guide who misidentified several plants. Richard had to gently supply the correct name for the species.

Also in his collection is an experimental round avocado developed by DT Fleming in Maui during the early 1900?s. It has survived 3 winters so far in Hencke?s Scotts Valley landscape so he is becoming more confident of its ongoing success. Took Richard quite a while to figure out which was the top of the seed. Being round he had stuck the toothpicks in the sides but put the wrong end in the water glass. He laughed that as soon as he figured out his error and turned it the other way up. It sprouted right away.

His Variegated Mint Bush at the edge of the back patio was just completing it?s blooming cycle but still covered with deep purple blossoms. Nearby we stopped at a very large clump of salvia confertiflora starting to bloom with showy red spikes of flowers. Richard lamented that it?s a little too happy. The clump has grown to near invasive size. ?Why did I plant this here? Now what am I going to do with it?, he said. This is a good lesson for all of us. The right plant in the wrong place can become a nightmare.

His collection of salvias that are planted in the right place include a beautiful salvia mexicana that will soon be covered with rich blue flowers. He also grows saeonium_blooms.1600alvia chiapensis and a salvia-like plant native to Hawaii called salvia lepechinia. This deliciously scented plant will be covered soon with reddish lavender lipstick-like flowers adored by hummingbirds like all the salvias.

The Hencke garden has a hillside for Hawaiian plants, a slope where he nurtures and propagate succulents, a shade garden for heliconia and houseplants that have adapted to his climate but trees are Richard?s first love. He showed off his hillside that is now home to sugar pine, silver poplar, gingko, alder, New England black cottonwood, tamarix, purple weeping birch and an Oklahoma Wild Sand plum that could win awards for it?s size and beauty.

Richard uses a Smart Timer to monitor and control his irrigation. That way he can use the minimum of water that allows his plants to survive. I put him in touch with another local gardener, Robby Frank, who helped him install the system. Gardeners are always pleased to help and share what they know and what they grow.

I enjoyed so many more plants and trees in Richard?s garden I could hardly keep up with the stories of their humble beginnings. As usual he packed my car with rooted cuttings and starts of many plants. I?m looking forward to the time when my Sacred Flower of the Andes starts to bloom.

Gardening for Frogs and other Creatures

Pacific tree_frog_on_potReading about the new wetland pond construction at the Ben Lomond SLV Homeschool in The Press Banner this past October 31st has me thinking about a low spot in my own garden that becomes soggy during the winter. Most mornings and evenings I hear the resident Pacific Tree frog singing his heart out. Maybe I can encourage even more frogs as well as dragonflies, salamanders and toads by installing my own wetland habitat. There are a lot of landscapes that I encounter that also have a ?problem? area with poor drainage and this would be the perfect solution. I?ve thought about building a wetland garden or bog garden for many years. This winter I?m going to do it.

The difference between a wetland garden and a bog garden is basically how long the water remains during the year. A wetland pond in our area is often seasonal, drying up in the summertime. A bog garden is damp even in the summer. A shady spot with a high water table is a good spot for a bog garden.

Wetlands are important to our ecosystem. One of the greatest wetlands in North America at Flame_Skimmer_dragonfiy-matingthe southern end of the San Joaquin Valley has almost completely vanished. There used to be almost 5 million acres of wetlands in the Central Valley and now only a small percentage remains. This habitat destruction is causing the disappearance of birds, frogs, amphibians and other wetland wildlife. You can help encourage these species in your own backyard and grow plants that are beautiful, too. Every little bit helps.

Most wetland plants don?t require standing water to grow successfully and will survive even in an area that appears dry most of the growing season. Many frogs including the Pacific Tree frog only need 3-4 weeks of water to lay eggs and the pollywogs to mature. Other frogs need a longer time to reproduce. The water need only be a little over a foot deep.

To create a wetland in an area that isn?t naturally moist and has heavy clay soil you will need to lay down a waterproof, nontoxic liner and cover it with soil. For a bog garden add decomposed plant matter and peat, Branches and logs can be placed around the edges as perches for birds and dragonflies and provide a spot for turtles to bask in the sun. Winter rains provide the best water to fill your wetland pond. Frogs and other amphibians are extremely sensitive to chemicals in tap water. Wildlife will be naturally drawn to your wetland. If you build it, they will come, I promise.

Blue_Damselfly-matingThere are many wetland plants that grow quickly when the soil in wet and then die back when the soil dries up only to return when moisture is again present. Species like cattails and rushes will do well being common in wetlands in our area. The plants you select depends on the amount of light, the length of time the soil will be saturated and the depth or water. Native trees like Big-Leaf maple, Red Alder and Box Elder are good companions for a wetland garden as are shrubs such as Snowberry, marsh baccharis and Yellow-twig dogwood.

Other native plants include Stream orchid, Deer fern, Horsetail, Cardinal lobelia, Twinberry honeysuckle, Cardinal Monkeyflower, Wood?s Rose, Blue Elderberry, Blue-eyed Grass, California Wild Grape and Giant Chain Fern.

Creating a mini-wetland in your own yard provides many of the same benefits that natural wetlands offer, providing habitat for creatures like butterflies, bees, salamanders, frogs and birds.