Riparian Buffers - Reforesting Waterways

Today we are going to write about Riparian Buffers - or planting trees and other plants along waterways.  This may seem like an odd topic given the blog's title of "The Arid Arborist."  However, we feel that the uses of trees should be enumerated at every opportunity, and proper care of our waterways encourages tree growth everywhere.  We will both discuss the uses and challenges of planting along waterways, and ways in which the Groasis Waterboxx may help.

First, what is Riparian Buffer?  A Riparian Buffer is a green zone planted with native trees, shrubs and grasses along a waterway that protect against non-point source (generalized) pollution, inhibit erosion, and provide habitat for wildlife.  These may also serve the very important goal of windbreak and flood mitigation.  Riparian is derived from "ripa" meaning bank in Latin, from which our word "river" is clearly derived.

Riparian Buffer in Iowa - From Wikipedia

Uses of Riparian Buffers

Sediment Removal - In one paper (Mankin, 2007), the authors found that Riparian Buffers stopped over 97% of sediment from entering the waterway.  This same study found over 90% of fertilizer components (which can cause choking algae blooms near the mouth of rivers) were stopped by Riparian Buffers.  The effects of erosion into our waterways can perhaps best be seen at the Mississippi Delta, were millions of tons of topsoil is lost to the Gulf of Mexico.

Windbreaks - While the research on Riparian Buffers as windbreaks is not as robust, the use of trees elsewhere as windbreaks is well known.  If being used for windbreaks in temperate regions (all of the United States), conifers should be used extensively as these will work in winter when deciduous trees have lost their leaves.

Flood Mitigation - Riparian Buffers allow heavy rains to more slowly reach waterways through several mechanisms.  First, plants form physical obstacles to water as it flows downhill (imagine a ball rolling down a flat piece of plywood versus a pegboard with pegs every 2 inches).  Second, the roots of the plants loosen the soil and allow water to percolate downward to underground aquifers rather than all staying on the surface.  Finally, plants transpire (absorb and then emit as water vapor) huge amounts of water, turning liquid water into water vapor.  If the Riparian Buffer is used for flood mitigation, grasses, shrubs and trees are useful.

Litter containment - it is deeply distressing to the author how much preventable litter we see floating into our nearby creeks.  Much of this is unintentional - trash left out for pick up and then blown into a creek by strong winds (another reason for windbreaks), but Riparian Buffers would enable the trash to be stopped before entering the water and becoming a danger to fish and other wildlife.  The trash is much easier to remove near the base of trees rather than from the bottom of a swollen stream.

How Can the Groasis Waterboxx Help?

What role can the Groasis Waterboxx play in Riparian Buffers?  We have tried multiple times before the Waterboxx to plant different trees along stream banks.  Our first effort we planted 2  8 foot tall Weeping Willows (Salix babylonica) approximately 5 feet above the level of a nearby creek.  We believed that rainfall would be sufficient to get the willows' roots to the moisture at the water level.  In this we were mistaken.  The summer following planting was very dry, and even weekly watering didn't save our willows.  Next we tried planting both one smaller weeping willow and several bald cypress (Taxodium distichum) right along the water level (during a relatively wet period in spring) realizing that our trees may be washed away in heavy rains.  Our trees were not washed away, but the bald cypress never bloomed due to unknown reasons (possibly because it was in a frost pocket which injured it).  This weeping willow did do quite well for a time, doubling the size of its canopy in less than a year.  However, during a dry summer spell, the water level of the creek fell well below the roots of the willow, revealing that the willow roots were barely in soil and mostly in the creek itself (now in open air).  The willow quickly died.  The Groasis Waterboxx solves both the problem of inappropriate amounts of water and frost pockets.  If we had planted our trees at the top of the creek bank with the Groasis Waterboxx, we would have provided the trees with just the right amount of water to sustain them during dry spells without opening them to flooding that would expose and then kill their roots.  The trees also would have been better positioned to serve their proper purpose in the Riparian Buffer, slowing flood waters and preventing sediment runoff.

The Groasis Waterboxx from Dew Harvest

The Groasis Waterboxx dramatically increases tree survival (up to 99% when done properly in one Sahara desert planting trial), and is reusable for up to ten years.  The Waterboxx can be purchased from Dew Harvest in the United States.

More information on Riparian Buffers is available here from the Arbor Day Foundation. We would love to hear your comments below - to leave one, please click on "Comments".

Sources: Mankin, K. (2007). Grass-shrub riparian buffer removal of sediment, phosphorus, and nitrogen from simulated runoff. JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, 43(5), 1108-1116. 

Evergreen Hedges - Tree Selection and Maintenance

     As Americans have rediscovered their back yards over the past several years and decided to spend more time in their current home because of the recent recession, more have decided to plant evergreen hedges.  The advantage of hedges are obvious - privacy, sound reduction from nearby streets and neighbors, habitat for wildlife, as a windbreak lowering heating costs in winter, and improvement in home value and curb appeal.  Unfortunately, we have seen a significant number of dead hedges over the past several years - mostly due to inappropriate trees for the area, inappropriately planted and insufficiently watered during the recent droughts.  We will attempt here to educate on the best types of evergreen tree for certain growing conditions, and how the Groasis Waterboxx might be useful in the planting of the hedge.  For the purposes of this post, we will only be discussing trees that grow at least to eye height (thereby blocking line of sight).

Arborvitae

      In the Great Lakes region where we are based, this is definitely the most popular hedge tree.  The Thuja occidentalis 'Emerald' variety seems to be the most commonly planted, but sometimes the faster growing if less picturesque Thuja standishii x plicata 'Green Giant' is used.  Both of these arborvitae (Latin for "tree of life") can be grown in zones 5-7, with the 'Emerald' variety hardy to zone 3 (see zones below).  

USDA Hardiness Zone Map - From Wikipedia

The 'Emerald' variety has a very nearly cylindrical appearance (with a slightly tapered spire), but tends to grow only about 12-18 inches per year, and reaches it maximum height of 20 feet slowly.  The 'Green Giant' variety can grow up to three feet a year under ideal conditions, and can potentially grow to 60 feet in height.  Both of the arborvitae are extremely sensitive to drought.  Over the last three summers, we have seen approximately 60% of established arborvitae die and 90% of newly planted arborvitae perish.  These trees, when bought potted from nurseries, almost always have a thick root ball when their base is removed from the pot.  Even when properly planted, these roots tend to stay near ground level, and will quickly dry out in periods of even partial drought.  One solution to deal with this is the rather arduous task of snaking a soaker hose throughout the trees every spring, and watering them thoroughly at least once weekly.  The soaker hose will need to be removed and stored before freezing in winter.  This can quickly become expensive, and tends to further cause roots to grow near the surface.  A (far cheaper) solution is to plant small bare root arborvitae (available from Arbor Day for as little as $2.49) using the Groasis Waterboxx.  The Waterboxx allows you to plant smaller, much cheaper (potted arborvitae sell for around $35 at big box home improvement stores due to the recent die off) arborvitae with properly formed roots.  The Waterboxx induces the roots of the tree to reach downward toward capillary water, not laterally (staying near the surface).  Because the Waterboxx contains a water reservoir and collects dew, you will not need to irrigate the trees after planting.  After approximately one year (depending on growth), the Waterboxx can be removed and reused.  You can calculate whether using a Waterboxx will save money during the first year using our calculator.  

Leyland Cypress

The Leyland Cypress (X Cupressocyparis leylandii) is also an excellent evergreen hedge tree, with the ability to grow much farther south than the arborvitae (up to zone 10).  The Leyland Cypress is also considerably more drought tolerant, as well as faster growing than the 'Emerald'  arborvitae.  The drawback to this tree is its mature size (up to 60 feet) and its susceptibility to infection.  As with the arborvitae, we recommend planting bare root Leyland Cypress using the Waterboxx, giving the tree an excellent foundation with deep roots.  The Waterboxx can be removed and used again to extend the hedge or to plant other trees.  

It is important to be a good (and thoughtful) neighbor when planting hedges, not planting tall plants that will block sun from reaching a neighbor's yard.  Also, each of the hedge trees discussed here can get certain diseases (arborvitae are susceptible to bagworms [Thyridopteryx ephemeraeformis] which appear to be pine cones at first sight) that will need to be dealt with immediately if spotted.  These diseases are more likely to take hold of unhealthy trees, another incentive to use the Waterboxx to properly establish the hedge at planting.

Be the first in your area to start growing plants with the Groasis Waterboxx. The Waterboxx can be purchased in the United States from Dew Harvest, with discount prices on orders of five or ten. We would love to hear your comments below - to leave one, please click on "Comments".

   

Hybrid vs O.P. tomato varieties

Tomato hybrids are F1 crosses between two stable inbred lines.  Since tomatoes are primarily self-pollinated, O.P. (open-pollinated) varieties are stable inbred lines – with perhaps a little variability from low level chance outcrossing.

The vast majority of all of the commercial tomato production in the world is with F1 hybrids, whether the hybrids are designed for processing or fresh market use.   Higher fruit yield in F1 hybrids is probably the biggest driver here, but stacking disease resistance genes is another benefit.  Since most commercial breeding companies are breeding for traits other than flavor – most F1 hybrids, with a few outstanding exceptions, are lousy in that regard.

Heirloom types, developed over many generations by families and/or communities, have been selected primarily for flavor.  These are all O.P. types, though I know there are some companies talking about heirloom hybrids - heirloom x heirloom I suppose.  Heirloom varieties typically have their own set of challenges: low yield, disease susceptibility, short shelf life, and/or fruit quality (cracking/catfacing, etc.) problems.

In the last several years several breeders have begun crossing commercial hybrids with heirloom types to get the best of both worlds – but that’s a different story.

As a tomato breeder I see intrinsic advantages in F1 hybrids – some obvious, others not.

Hybrid vigor or heterosis.   This is usually simply defined as performance in the F1 that is better than either of the parents.   Numerous scientific studies report and commercial tomato breeders have demonstrated the potential for heterosis for fruit yield, and there is substantial evidence of heterosis for other
traits (reference; pages 115-127), including sugar and acid content - key drivers for flavor (reference).  We make several dozen new F1 crosses every year and in many cases we see exceptional flavor in the F1 generation that we never successfully stabilize in succeeding filial generations.  Several years ago my friend Bill Jeffers sent me seed of a F1 cross he made (Indian Stripe x Sungold).  Flavor in the F1 generation was out of this world, and to our mutual disappointment we were never able to capture anything close to this in F5/F6 lines.  Another breeder friend Keith Mueller has commercialized the F1 hybrid “Purple Haze” derived from a cross between Black Cherry and a (Brandywine x Cherokee Purple) line he developed.  He says that this specific combination demonstrates heterosis for flavor that stands out from other similar crosses he tested.  I am confident there is heterosis for flavor in tomato, but realize it will require a lot of test crossing to identify parents that fully capture this.

    Stacking disease resistance traits.  Wild relatives of tomatoes have been a rich source of genes for resistance/tolerance to key tomato diseases.  With few exceptions these disease resistant genes are inherited as dominant alleles – e.g. Resistant x Susceptible = Resistant.  In a F1 hybrid typically one parent will be resistant to one set of diseases (e.g. ABC), the other resistant to another set of diseases (e.g. DEF) with the hybrid then resistant to both sets of diseases (e.g. ABCDEF).  This has proven to be a very effective way of stacking disease resistance in tomato varieties.

Some genes are desired in the heterozygous state.  In inbred (i.e. O.P.) lines the plants are homozygous at virtually all loci.  For a particular gene/locus the heterozygous condition is only possible in a hybrid, or an unstable segregating population.  The recessive rin allele is involved in fruit ripening.  In the homozygous state the fruit never ripens, in the heterozygous state (rin/+) there is delayed ripening of the fruit, providing extended shelf life (reference).  Many of the vine ripened tomatoes (cherry, grape and cluster) now being marketed in grocery stores are rin/+ F1 hybrids.  The NC State rin/+ hybrid Mountain Magic is an excellent example of a tasty tomato with exceptional shelf life (and state of the art multiple disease resistance).   More recently a discovery was reported that a loss of function mutant allele in the gene SFT, which codes for the flowering hormone florigen, had a profound effect on plant growth in tomatoes.  Homozygous sft/sft plants had significantly delayed flowering and low yield, heterozygous plants sft/+ (in determinate plants)  had 60% higher yield (photo above) and enhanced flavor (reference).

New F1 hybrid (Aft/+)

Complementary traits.  Some of our best inbred lines absolutely nail some traits (e.g. flavor and/or fruit type), but have one or more key weaknesses (e.g. splitting, poor seed yield, late fruiting or plant architecture).  By selecting hybrid parents that compliment each other for key traits, we’ve identified F1 hybrids that are clearly superior to the parents.  This is perhaps another ramification of the heterosis discussion above.

There are only two disadvantages of hybrids vs O.P. varieties that I can think of:  a) seed production is more complicated, more expensive and grower saved seed is not an option; and b) a significant portion of the customer base for tasty locally grown (homegrown or farmers markets) fresh market tomatoes has an anti–hybrid bias, unfortunately often confounding F1 hybrids with GMO traits, organic vs conventional, or big biz vs family owned operations. 

Frogsleap Farm is a two person husband and wife breeding team, working with the best heirloom and commercial hybrid germplasm we can find, and developing novel varieties (including F1 hybrids) for both organic and conventional producers.   We think both F1 hybrids and O.P. varieties will have a place in an exciting marketplace of unique and tasty tomato varieties adapted for use by home gardeners and small to medium sized tomato producers.

The Figure Eight Central Opening of the Groasis Waterboxx

The Waterboxx took a great deal of time and money to design (seven years and over seven million dollars) and all aspects of it were carefully considered.  An interesting aspect of the the Waterboxx is the figure eight central opening.  This is shaped this way for several reasons, detailed below.

The Waterboxx is designed to work well enough to grow trees in the desert.  In a Sahara planting trial, 88% of single saplings planted with the Groasis Waterboxx survived.  This compared to only 10.5 percent of non-Waterboxx trees that were watered once weekly surviving.  While the 88% survival of the Waterboxx trees is great considering the very inhospitable conditions in the Sahara (no trees naturally grow there), the Waterboxx is a significant investment, especially when purchased in large quantities.  If the survival rate of trees using the Groasis Waterboxx was closer to 95%, the investment would have a much better return.   Mr. Pieter Hoff, the inventor, decided that the Waterboxx should have enough room to plant two small saplings in its center.  This allows natural selection to be used, allowing trees to compete for light and resources.  After one year, the stronger (meaning taller and healthier looking) of these two trees can be spared while the weaker is cut at the base.  In this way, the chance of one tree (out of two initially planted) surviving in the driest harshest conditions in the Sahara is now 99%.  The relevant math formula is (0.88+0.88)-(0.88*0.88) = 99%.

Secondly, the length of the central opening of the Waterboxx is meant to be oriented East-West.  This allows sunlight, originating in the East and traveling overhead toward the West, to reach the trees through most of the day.  The Waterboxx even has a compass rose imprinted on its lid to help with orienting it correctly.

The blue cap and lid overflow are to be placed on the north of the Waterboxx to maximize sun exposure (image courtesy of Groasis)

So the central opening of the Waterboxx allows two trees (or even one tree and one other annual plant as seen below) to be planted, with the stronger one surviving the first year.  It allows sunlight to reach the growing plants during most of the day, while the rest of the Groasis Waterboxx prevents the soil from drying out and weeds from competing directly with the Waterboxx plant.  Finally, the Waterboxx's narrow opening prevents wind from drying out the young plant during its first year critical period.

Once the Waterboxx planted tree has a growth spurt, after about one year, and its canopy becomes so large it may soon have trouble fitting through the central opening, the Waterboxx is removed and reused up to 9 more times.  The tree then has a mat or mulch placed around its base, and is drought resistant due to its deep, Waterboxx induced roots.

The Waterboxx is available for purchase from Dew Harvest in the United States. We would love to hear your comments below - to leave one, please click on "Comments".

The Lotus Leaf Inspired Waterboxx Lid

Plants have had hundreds of millions of years to acquire traits that are useful to them.  Most people are familiar with plants that can snap shut on insects (Venus' Flytrap or Dionaea musipula) in order to digest their bodies for nutrients.  The Toxicodendron genus, including poison oak, ivy and su mac, produce an extremely irritating oil that prevents the plant from being eaten (or easily removed).  Unknown to many lay people, however, is the incredible ability of the lotus leaf to rebuff water.

For much of the last half century, botanists have known that the lotus leaf exhibits very high water repellence, or superhydrophobicity.  This is useful to the plant because as water is slicked off the surface of the lotus leaves, dirt, bacteria, and algae are also washed off by this water.  This allows the lotus to prevent blockage of photosynthesis by dirt, and protects it against other parasitic organisms (the bacteria and algae).

Water sticks to most surfaces, but not the lotus leaf - From Ralf Pfeifer via Wikipedia 

The reason for this strong water repellence was elucidated by examining the surface of the lotus leaf at the microscopic level.  When looked at with an electron microscope by the botanist Wilhelm Barthlott, the lotus leaf was seen to have tiny pyramids or papillae.  These points minimize the contact the water has with the surface, preventing strong bonds from forming between the leaf and water droplet.  This is illustrated below.

Graphic by William Thielicke showing pyramidal structure of the surface of the Lotus leaf.  This surface guarantees that water won't stick to the surface of the lotus leaf, or the Groasis Waterboxx lid that has similar microscopic pyramids on its surface.  

As the water won't stick to the surface of the leaf, it slides off, taking substances and organisms harmful to the lotus with it.

A device which mimics this property was developed a few years ago for the planting of trees in very dry places.  Its designer knew that for as much rain and dew to be collected as possible, the lid or collecting dish would need to hold onto very little water, instead channeling it to the roots of a plant.  This device was called the Groasis Waterboxx.

When Pieter Hoff was designing the Groasis Waterboxx, he wanted to ensure that all possible condensation and rainwater that fell on the lid of his Waterboxx was channeled into the Waterboxx basin for later use by the plant.  He of course used a sloped, corrugated lid, made of polypropylene (a plastic known to be water repellent).  However, he also added pyramids to the surface of the lid at the microscopic level, mimicking the ingenious lotus effect.  All of these features meant that even a very thin layer of dew deposited each night could be saved and used by the growing plant.  The ability of the Groasis Waterboxx to propel water downward in shown in this video.

People assume the smoothest surfaces are the slickest, but this is not true when it comes to water.  Water cannot form strong bonds on the surface of the lotus leaf, and for the same reason it can't stick to the surface of the Waterboxx.

The Groasis Waterboxx took over seven years and cost over seven million dollars to develop.  You can, however, buy the Waterboxx today for less than fifty dollars (and significantly cheaper for large orders), and use it for the the next decade to grow drought resistant trees.  Visit us at Dew Harvest. We would love to hear your comments below - to leave one, please click on "Comments".


Our Sources:

http://news.nationalgeographic.com/news/2003/02/0227_030227_lotusmaterial_2.html

http://en.wikipedia.org/wiki/Lotus_effect

http://www.youtube.com/watch?v=LJtQ6dvcbOg

How To Help A Tree To Survive Drought

Drought has become an increasingly common and severe problem across the United States.  In my own area of Indiana, we have seen three extremely dry summers, culminating in the truly impressive drought of 2012 in which multiple mature trees died, and almost all newly planted trees perished.  Much of the U.S. west of the Mississippi is still mired in drought.  So the question arises, under these dry circumstances, how do we help trees survive drought?

As mentioned, the trees that are most vulnerable to drought are those that are newly planted.  Most people have grown accustomed to buying fairly large (~6-8 foot in height) trees at local garden centers.  These trees are grown in pots, and usually have very thick secondary root systems, frequently circling the interior of the pot.

Even if planted using the best techniques (discussed below ), these roots will mostly grow laterally, staying near the surface.  This lateral growth allows them to absorb rain right after it falls, but also makes the roots very susceptible to drying out in periods of drought.  When rain is infrequent, the area closest to the top of the soil dries out first.  If all or almost all of the tree's roots lie in this top soil zone, then the tree can quickly dry out and die (or become more susceptible to other diseases like pests).  For this reason, it has long been advised that you water trees deeply yet infrequently, in an attempt to get these roots to grow more deeply.

In practice, store bought trees with such thick root balls can rarely have their roots redirected downward.  When you have a new, store bought tree, the best you can do is dig an appropriate hole (twice the width and one times the depth of the root ball) and make sure the tree stays watered when there is no rain.  An alternative is to use a watering bag like the TreeGator®, but these bags also need to be refilled by a human, not saving much effort but greatly increasing cost.  

Buying trees from garden centers often leads to disappointing results. According to Richard Harris, Professor of Environmental Horticulture at UC-Davis, "the smaller the plant when transplanted into the landscape, the better will be its relationship to the environment" (Kourik, 2008).  For this reason we recommend the method of planting detailed below.

A new and better way to grow trees that will be permanently drought resistant is to grow younger trees (saplings) that still have their primary (tap) root, and to grow these trees with the Groasis Waterboxx.  The Waterboxx is a deceptively simple invention.  It functions in multiple ways to ensure that tree roots grow downward, not laterally near the surface.  It does this by collecting dew and rain water and slowly channeling it to the taproot of the tree.  The slowly released water forms a column beneath the Waterboxx, and the trees roots will grow straight down within this water column.  "When it comes to moisture, roots are lazy.  They won't grow to a water source, but will grow where there is moisture."  (Kourik, 2008).   After this root growth, the Waterboxx can then be removed, leaving behind a tree with a deep taproot that has much better access to deep moisture in the soil.

As you can see in the video above from Groasis, the Waterboxx will make trees resistant to drought long term, thus allowing the landowner to conserve water.  If you are interested in purchasing the Waterboxx, please visit our parent website, Dew Harvest. We would love to hear your comments below - to leave one, please click on "Comments".


Kourik, R. (2008). Roots demystified: change your gardening habits to help roots thrive. Occidental California: Metamorphic Press.

Growing Grapes without Irrigation (and with the Groasis Waterboxx)

Wine is one of the hallmark beverages of civilization, and for most people drinking it is a everyday luxury.  However, rarely do we think about the amount of inputs that go into one bottle of wine.  Vineyards are frequently located in arid regions, and these vines are frequently irrigated.  The Economist recently published a piece about the amount of irrigation water that goes into making one liter of wine.  The result - approximately 950 liters of water go into every liter of wine, or over 700 liters of water per 0.75 liter bottle of wine.  This means over 175 gallons of water go to make less than one quart of wine.

Water shortage is unfortunately going to be one of the defining characteristics of the Twenty-First Century.  Surely there must be a better way to grow grapes than with traditional irrigation that wastes so much water.  Luckily, there is - The Groasis Waterboxx .  The Groasis Waterboxx is an ingenious invention by a Dutchman named Pieter Hoff.  The Waterboxx is a self-recharging water battery for trees - it collects dew water each night (and rain when it happens to fall), directs a small amount to the roots of a growing plant, in this case grape vines.  The roots grow deep to underground water, and the Waterboxx prevents evaporation of the moisture in the soil immediately around the grape vine.  In this way the Waterboxx greatly helps to conserve water.  The one year results of grape growing with the Waterboxx can be seen below.  The Waterboxx requires water only during initial set up.  The inventor recommends 8-12 gallons be slowly poured on the planting site, then 4 gallons be placed in the reservoir (green basin) to be slowly released.  You can learn more about the Waterboxx at our parent website, Dew Harvest. The incredible results of the Waterboxx in the desert, growing grapes, is seen below.  

Grape vines two months after planting with the Groasis Waterboxx. (Photo courtesy of Groasis.com)

The same grapes 4 months after planting with the Waterboxx; significant growth is already evident. (Photo courtesy of Groasis.com)

The vines continue to grow 6 months after planting.  (Photo courtesy of Groasis.com)

The same grape vines twelve months after planting.  The Waterboxxes were not refilled during this time, but collected dew and rainwater and funneled this to the roots of the growing plant.  The Waterboxx will stay in place indefinitely for these vines (it lasts up to 10 years), further assisting in watering of these grapes. (Photo courtesy of Groasis.com)

We would love to hear your comments below - to leave one, please click on "Comments".