Category Archives: dry river bed

Lessons in Water Conservation

There’s a saying that you should learn something new everyday and while visiting Robby Franks’ Scotts Valley garden recently I added valuable lessons to my irrigation know-how and successful succulent and other low water-use plant cultivation.

robby_frank_slope_sept2016_Slope with dry creek bed, succulents and other low water-use plants.

You might remember a prior column of two about this “serial mole killer” as Robby laughingly described himself several years ago. He told me he’s licked his huge mole problem by exclusion and trapping plus he’s been the benefactor of a large gopher snake and a couple king snakes from the neighbors so he’s pretty confident now that his garden and all the work that goes into dividing and transplanting and mulching will not go in vain.

The soil in Robby’s garden is quite sandy and thin. He’s done wonders adding his own compost over the years. We all know mulching is one of the best ways to conserve water in the landscape. Robby has long been an advocate of composting and regularly renews the mulch in his garden. He even calls himself “Mr Mulch”. He has permeable paths and a dry river bed that allow rainwater runoff to soak into the soil slowly. He keeps his plants pruned in a naturalistic manner because “smaller plants use less water'”. But all this wasn’t enough. His 3 “dumb timers”, as he calls them, were using too much water. That’s when he started researching weather based smart irrigation timers.

robby_frank_garden1The dry creek bed

“To me it seemed like an easy way to conserve water and it’s better for the plants as well”, Robby said. “It will increase the irrigation times if the weather is hotter and dryer than usual, decrease it if colder and turn itself off if it rains”. After research Robby eventually chose the Rainbird ”Simple to Set” Smart Indoor/Outdoor Irrigation timer.

At a raised feeding platform a covey of quail were enjoying an afternoon snack. Below a group of Mexican marigold, fortnight lily, society garlic and euphorbia were thriving and Robby explained they are all watered with one irrigation hub called an Apollo 8 Port Bubbler. It is simple to install and screws onto an existing sprinkler riser or other 5/8” tubing. Each port can be adjusted to deliver just the right amount of water to each area. Attached a micro spray to the end of the 1/4” tubing and plants grow larger and deeper root systems.

robby_frank_garden2Collection of plants requiring little irrigation

Robby’s garden is a diverse collection of plants from all over the world. He told me he’s been impressed how the cordyline are growing and considers them better performers than the popular New Zealand phormium in both heat and cold conditions. But succulents are his passion. He’s got five varieties of sedum, three types of aloe including his favorite ‘Red Tip’, two varieties of sempervivum although he laments they are slower growing then he’d like, echeveria and his new favorite plant, Dyckia ‘Red Devil’. Although technically not a succulent but in the genus bromeliad it does have similar characteristics. “They remind me of an underwater scene”, he said. Their dark, spiky foliage did look a bit like giant sea anemone.

Robby does a lot a research and loves to share the knowledge he’s gained about plant cultivation and irrigation. Many a garden in Scotts Valley have benefited from his passion. Robby Frank is on a crusade to save water and Smart Irrigation and mulching is one way to do it.

Sheet Mulch Away that Old Lawn

Replacing that water guzzling lawn or dramatically reducing the size is a good place to start conserving water and is easier than you think. If you’ve been paralyzed with the thought of digging out and hauling away hundreds of square feet of heavy sod or using dangerous grass-killing chemicals, sheet mulching is the method for you.

sheet_mulching_in_progressSheet mulching in progress

This simple technique eliminates the lawn by smothering it with layers of compost and renewable materials. Here’s how to do it:

  1. Mow the lawn down to 1-2”, leave the clippings in place and soak with a hose.
  2. Flag the locations of sprinkler heads you will be keeping for your new plantings and cap off the ones you won’t need.
  3. Add an inch of compost to speed up the decay of the grass. If your lawn borders a driveway, path or sidewalk you’ll have to remove about 3” inches deep of soil along these edges and back 8-12” so that the new mulch doesn’t slide off into the sidewalk.
  4. Put down 2-3 layers of newspaper or one layer of cardboard overlapping the edges by 6-8” to prevent regrowth at the edges. You can buy recycled cardboard in rolls for larger projects or find your own at appliance or bicycle stores. Wet the cardboard or newspapers to keep them in place as you go along. It’s best to use cardboard or newspaper thatwill break down quicker. Don’t use plastic sheeting because water and air cannot penetrate it.
  5. Add a 3” layer of mulch such as bark chips from a tree trimming company. You can use compost, straw or shredded plant material. If you have Bermuda grass or other weeds like oxalis you will need to layer about 8” of mulch to smother them.
  6. Water thoroughly.

sheet_mulch_installPlants installed immediately after sheet mulching

If you can wait a month or more to let the decomposition process get going so much the better. If you just can’t wait you can begin planting now by scraping away the mulch and poking a hole in the cardboard or newspaper where the plant is to go. Then add some compost to help the new plant become established. Be sure to plant high enough to prevent crown rot and keep the mulch a couple inches away from the stem. The top of the root ball should be 1-2” above the soil and just below the mulch.

Modify the sprinkler to drip and remember to adjust your irrigation system run times to accommodate your new plantings.

This is a basic “lasagna” method for lawn removal. If you are planning to replant with water smart grasses you would choose finer composted mulch instead of bark chips. Either way the process works on the same concept as a compost pile. As the lawn dies from lack of light, it decomposes with the activity of beneficial worms, insects and microorganisms coming up from the soil and doing their job to break down the nitrogen and carbon in the sheet-mulch layers. It’s a win-win situation for the environment and your water bill.

sheet_mulching_one_year_afterOne year after lawn removal by sheet mulching

Water conservation starts with losing or reducing the thirsty traditional lawn and reducing irrigation. Transform your landscape into a resilient garden that not only saves water but acts to build the earth into a living sponge that harnesses rainwater and replenishes the aquifer at the same time. Attracting wildlife to your new beautiful garden is a bonus.

Be sure to apply for your rebates and have your lawn inspected, even if it’s dead, before you start.

Dry River Beds – Beautiful & Beneficial

dry_river_bed1Dry 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

OLYMPUS DIGITAL CAMERADry 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.

OLYMPUS DIGITAL CAMERAPheasant 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.