Saturday, April 19, 2008

Simple Drip Emitter Tubing

It’s irrigation season on my friend Chester’s garlic farm. The garlic has been growing all winter but now needs irrigation until July or so. That's him to the left, 85 and still growing and eatin' garlic.

About 18-years ago, I helped put in a simple drip irrigation system for each of his 4-foot by 10-foot planter boxes. I insisted on in-line emitter tubing.

In-line emitters are still probably the least well-known drip irrigation technology, but afford the best mix of efficiency, ease of installation, and resistance to clogging. The tubing is 1/2-inch in diameter with an emitter pre-installed inside the tubing at regular intervals.

These internal emitters seldom clog because they utilize what is known as a "tortuous path,” which forms a continuous vortex, a kind of horizontal tornado that keeps any sediment, sand or silt in suspension until it passes out of the emitter. (See the illustration above or in my books Drip Irrigation for Every Landscape and All  Climates or in Roots Demystified - Change Your Gardening Habits to Help Roots Thrive. Click on the illustration for a bigger image) In-line emitters even work with well water high in soluble iron-oxide or other minerals. In-line emitter tubing moistens the soil the entire length of the line, but slightly below the surface where the bulbous-shaped wet spots come together to form one nearly continuous moist zone.

The emitters come pre-installed in the tubing, which is most commonly sold in pre-spaced, 12-inch intervals—but also comes in intervals of 24- and 36-inches. The emitters inside the hose are rated to dispense either ½ or 1 gallon-per-hour (gph) and the hose is available in both non-compensating and pressure-compensating versions.

We used ½ gph pressure-compensating emitters on 12-inch spaces along the tubing. We placed three equally-spaced lines running down the length of every box. (See upper-left photo. Taken before the straw is added.) Each box has the three lines connected to the water supply and the other ends connected to a drain-down manifold to flush the system at the beginning of each irrigation season. That’s what Chester is doing in the right-hand photo above. The garlic has grown considerably during the rainy winter months.

The benefits of pressure-compensated in-line emitters are: it's easy to install, simple to snake around your existing plantings, it is easy to put together a simple array of tubing which can be readily removed from the vegetable beds for seasonal cultivation, suffers less clogging than porous tubing and most punched-in emitters Chester stopped using the filter several years back and still only a handful of plugged emitters. Even with iron-based irrigation water only a few emitters in the thousands of feet of tubing have clogged over the past 18 years, and not cracked or leaking. Warranty says 10 years, but this tubing is always under six inches of mulch, works at the greatest range of pressures (9-25 psi), provides consistent rates of irrigation without regard to slope or length, has no external parts to snap off (a premier advantage over all punched-in emitters), and the compression fittings don't leak and seal better than the hose clamps used with porous hose.

The regular interval of the emitter makes it easy to irrigate the entire root system of all vegetables—in this case, garlic—and ornamentals by simply running parallel line of tubing throughout these raised beds or any garden. This will insure the greatest yields when compared to any other irrigation method—even sprinklers.

The drawbacks are few: it requires extra planning for plants placed very far apart and at very odd intervals, it can't turn a sharp radius, and it’s not carried by very many retail outlets.

You can get by mail from Harmony Farm Supply & Nursery, Peaceful Valley Farm & Garden Supply, and DripWorks (one word). Google them for what’s sold on their web site. You may have to order from one of their printed catalogs.

Let me know if you’ve tried in-line emitter tubing. How did it work for your garden?

All rights reserved, Copyright 2008

Visitmy web site to learn about my gardening books.

NOTE: The comments section at the bottom of the post has disappeared. Click on the "___ Comments" button or the title under the "Blog Archives". Thanks, Robert

Labels: Chester Aaron, drip irrigation, emitters, gardening, garlic, in-line emitter tubing, irrigation, raised beds

Tuesday, April 15, 2008

Deer Fencing With a View, building one.

The old way to keep deer at bay was ugly.

Deer fence barriers have usually been made with woven wire mesh up to six feet and several horizontal strands of wire above that, creating a prison-perimeter that looks like Stalag 13 and that's not acceptable for most suburban or rural yards.

It's spring and the fawns will soon be looking to stake out new territory. Testing every fence.

I learned of a special fence that had a 20-year track record of keeping deer out. Because no part of the fence is taller than four feet, the home owner's view remains mostly unobstructed; the double placement avoids the looming ugliness of the tall eight-foot agricultural version while being, in my area, just as effective. There have been at least five replications of this type of fence after I built this model. They all work.

The fence are both only four-feet high. The two four-foot high fences are built five feet apart. (See the photo in the upper right above.) Since deer can’t talk, I’m left to guess why this seemingly uncomplicated design is so effective. The most common theory is that the deer can’t see enough room between the two fences to land and then rebound over the inner fence. For whatever reason, this configuration seems to work on both flat and sloped sites. The fences must be in the open"meadow" as a neighbor built one in the forest and it didn't work. (I was the first to take the bold leap to build one on a gradual slope.)

Both four-foot fences can be made with 2"X4" inch wire-mesh fencing attached to six-foot metal stakes pounded two feet into the ground. Or, for a more aesthetic look, the most visible areas of fencing can be made of wooden boards, pickets, or grape stakes. Because it requires additional posts and hardware, the cost of the double fence will be somewhat higher than that of an eight-foot barrier, but the unencumbered view is often worth the expense And working at four feet or less is much easier for the weekend fence builder.

I staggered the top of these grape stakes by six inches and left a gap as wide as a grape stake to give the fence a lighter feel. The inner wire fence was planted with honeysuckle, that rapidly obscured the wire and continued to be effective.

With two fences, two gates must be built at each opening. One attractive solution is to incorporate two four-foot gates into a five-foot-square eight-foot-tall arbor, which can also serve as support for climbing roses planted inside the inner fence. (I learned from the client that five feet was bit to tight to easily pass through with a wheelbarrow —it worked but is a tight, knuckle-scrapping width. So, all future designs will have a six-foot wide arbor.)

I decided to have the grape stakes on the gates reflect the curve of the arbor. I used cardboard to sketch the curve, flip it, and use it as a template for the stake. (See the illustration on the lower left.) The finished arbor, as seen above is attractive. However I felt I was taking a chance as the deer might use the hole to jump through. Luckily, after over 20 years no grazing ungulates have traversed the gate.

The client planted deer-resistant English Lavender (Lavandula angustifolia) grown from seed on the outside of the fence. Because the plants were grown from seed, there is a wonderful array of blossom colors—from typical lavender blue to royal blue to pastel blue and even almost pure white.

The combination of the lavender on the outside (the fourth photo) combined with the inner fence covered with honeysuckle and the fence nearly invisible. A pleasant, and fragrant, way to deter these beautiful, yet destructive-eating machines.

For the plantings outside the fence, it's important to realize that deer, their habits, and their appetites are always changing. However, in my garden, lavender has been untouched for 25 years. What deer eat and what will fence them out, varies throughout the country. Try each new strategy in moderation until you find out if it works. The answers to deer browsing will always remain as diverse as our local environments.

I built this fence nearly 20 years ago and no deer have crossed it. Once a mighty buck got trapped between the two fences. Luckily, he jumped out the way he came, away from the prized roses, strawberry plants, fruit trees and countless other delectables. If you don’t move to fast you can often slowly walk an animal back to where it breached the perimeter to see how it got in.

I rent my home and the layout of the house to the road and the garden would make it very difficult to construct a double four-foot fence. And the cost would be prohibitive. So I’ve settled upon planting deer-resistant exotics.

I wonder if this double fence will work in cold-weather areas where winters are snowy and harsh and deer become desperate. For one thing, snow drifts might make it easy for the deer to simply walk up to and over the four foot height. If you know of such a fence in your area, please let me know. For much of the west, it’s a solution worth experimenting with.

Electrical fencing, which provides a safe but deterring shock, is a common solution the snow parts of the country. A popular electric fence for parts of New England is a low-profile, five-foot-tall electric fence made of high-tensile wire.

Please post a comment - I want to know what you think.

All rights reserved, Copyright 2008

Visit my web site to learn about my gardening books.

NOTE: The comments section at the bottom of the post has disappeared. Click on the "___ Comments" button or the title under the "Blog Archives". Thanks, Robert

Monday, April 14, 2008

Greyt Detergents for Grey Water Systems

It’s time to turn the illegal valve to use my grey water.

Soap is soap, and most laundry detergents appear to be just the same old detergent. This is fine, unless you have a grey water system designed to irrigate your favorite petunias or roses with the used water from your washing machine. Plain soap, which is made from stuff like animal fat and lye (wood ash), doesn't stop minerals in the wash water from depositing a dirty "smog" on your favorite pure-white undies. So, over forty years ago, Procter & Gamble invented Tide as the first heavy-duty synthetic laundry detergent.

Detergents, fabricated from a variety of chemicals in addition to soap, are engineered to enhance the soap's cleaning capability and avoid graying those undies. But, alas for grey water users, chemicals in detergents are selected with only their clothes-washing capabilities in mind, and with no thought for a thirsty root's sensitivities.

To choose the best detergent for a grey water system, you'll have to read product labels. First, look for the most important element to avoid: sodium. Unfortunately, the amount of sodium in most detergents is impossible to ascertain, and they won't tell you on the 800-consumer phone line because "It's proprietary." As a rule, popular liquid concentrates have much less sodium than powdered detergents, which use cheap sodium-based compounds to bulk up the product.

Next, look for the words boron, borate or Boroteam. Boron rarely kills plants, but it will cause an ugly leaf-margin burn, and can be a real problem with alkaline soils in desert areas. Worse still, once boron is added to soil, it is not easily leached out. So skip all detergents with boron.

Phosphates chemically inactivate calcium, magnesium, iron and manganese without making a precipitate (depositing a grimy "smog" on cloth). These are the chemicals blamed in the 1970s for "ruining" lakes and rivers (it's since been learned that laundry phosphates weren't always the significant culprit). Actually, phosphates are a great ingredient for a grey water system because roots utilize them like a fertilizer. Since a grey water system is managed for the improved growth of the plants, buy a high-phosphate detergent—if you can find one (many states have banned in as an ingredient). Because you'll be monitoring your grey water system, you can make sure phosphates aren't leaching off your property to turn rivers or lakes green.

Finally, watch out for chlorine, which in its concentrated form is a very caustic, toxic and deadly chemical. The amounts of chlorine in detergents are actually quite low, but the prudent gardener will avoid this chemical altogether. (However, I have used chlorine bleach on occasion in the laundry and to remove stains in the bathtub, and have yet to see any visible consequences in my landscape.)

A quick survey of any supermarket will soon reveal a plethora of detergents either useless for grey water or, at best, ambiguously labeled. What's a lawless grey-water user to do? (It's still illegal in most places to use grey water.) I shop for a more “Earth-friendly” detergent but get the full scoop on boron, sodium, and chlorine.

For the latest on grey water developments, see the web site of the Guru of Grey Water, Art Ludwig:

Please post a comment - I want to know what you think. Are you an illegal grey water user?

Visit web web site to learn about my gardening books.

All Rights Reserved. Copyright 2008

NOTE: The comments section at the bottom of the post has disappeared. Click on the "___ Comments" button or the title under the "Blog Archives". Thanks, Robert

Living With the Roots of an Oak Tree

I laugh (and cry) at the little orange fences they put around oaks during construction. They are nearly worthless. While it keeps vehicles for hitting and scaring the bark, it in no way protects the feeding roots.

As a maintenance gardener I’ve had to dig up a few oaks. And just below the ground the roots have a covering much like bark. Bark absorbs very few nutrients. In a study of 25-year-old apple tree in the UK found that the first four feet from the trunk accounted for less than 10% of all the water and nutrients absorbed.

The wobbly-orange fences are, at best placed at the edge of the foliage. A good start as it may help to keep water off the trunk’s base. But this is a far cry from protecting the majority of the root system’s feeding roots.

In the photograph to the left, the construction company dutifully surrounded the oak’s dripline. But all the machinery and the house itself cover what used to be the leaf litter, duff, and organic mater (humus) that once both fed and protected the young feeding roots.

The tiny root hairs, that live for just a day or so, tend to grow up into the fertile strata of the humus and duff zone. They, like all plants, want to be the first to capture liberated nutrients as they become avaiable. As one researcher put it—“roots grow up not down”. While a bit overstated, they fact is the youngest rootlets and their root hairs reside well beyond the canopy of the tree, where all the construction is taking place. (Learn more in my book Roots Demystified,)

(See my Blog of March 31st to see diagrams of the extent of a roots wanderings.)

At one-half to thee times, or more of the width of the dripline roots gather nutrients and moisture far from the trunk or even the canopy.

The photo (on the above right) of the chairs face south along the Big Sur coastline are a good attempt to protect to crown of the young California live oak from moisture in the summer. The gravel does allow rain in the winter to percolate down along with oxygen and harmful gases escape. The compacted gravel is a bit hard on the feeding roots, but the tree seemed health. Perhaps this is one solution to living among oak woodlands.

Please post a comment - I want to know what you think.

Visit my web site to learn about my gardening books.

All Rights Reserved. Copyright 2008

NOTE: The comments section at the bottom of the post has disappeared. Click on the "___ Comments" button or the title under the "Blog Archives". Thanks, Robert