Tuesday, November 13, 2012

Test That Soil!

Ok, so it took a while to get started on soil basics for vegetable growing but lets get going with it and then we'll move forward into some more detailed gardening information for the Permian Basin over the course of the next few weeks.

To begin growing veggies, you need to understand what kind of soil you have and that can only be done properly with a soil test performed by a laboratory.  A soil test will give you an idea of the texture or parent material of the soil in which you'll be growing vegetables. There is little you can do to immediately change the texture.  Most West Texas soils are somewhat sandy but heavily composed of limestone which was deposited, according to the experts that spend a lot of time figuring out this kind of stuff, millions of years ago.  Its going to take a little time to improve the soil texture and this is done by amending the soil with organic material.

Please note that texture can't truly be changed without digging all of the soil out and starting over with lots of new soil from some alluvial (mineral rich deposits from flowing water) source and that's simply not practical.  The solution is to use lots of composted organic material which is the topic of the next blog.  For now lets just stick to foundational reasons to start your gardening with a soil test.

The test will also give you an idea of its pH and fertility.  Soil pH is a measure of soil acidity.  Soils with a high pH are called basic and are common in the Permian Basin.  As you can see by carefully examining the graph below, basic soils, or those soils above a pH of 7.0, begin to tie up iron, manganese and zinc.  The higher the pH, the greater the reduction in the availability of these nutrients no matter how much is in the soil.  Iron is a particular problem for development of healthy and productive vegetables since it's a primary component in chlorophyll.  Iron deficient plants often exhibit symptoms of yellowing between the veins of leaves.  This is known as interveinal chlorosis and leads to a lack of carbohydrate production by the plant and poor development or perhaps in extreme cases, starvation of the plant to the point of dying.

Dead plants can't grow veggies so what's the solution?  Many people add chelated iron to the soil but this is temporary.  Most astute gardeners add amendments and grow vegetable varieties that are tolerant of our pH (another topic we'll fold into the blog soon).  Some vegetable growers use fertilizers that help decrease the pH but again this is temporary and the effect is limited.

So for now, just start with an understanding of what kind of soil you have by getting it tested.  You'd really, really be surprised by how rarely this is done.  A lot of folks go out and spend their hard earned dollars on plants from the local nursery and plug them into the ground without any knowledge about their soil.  A soil test is a must.


Tuesday, November 6, 2012

Parasites attacking Drought Weakened West Texas Trees

Here we go again!  Another tree parasite making its way into our lawns.  This interesting looking conk belongs to the Ganoderma family of Fungi and is another noxious little creep that makes its living by feasting on our trees.  Ganoderma is frequently found wrapped around the base of West Texas Honey locusts and Red oaks and each tree exhibits a unique mortality spiral once infected.  Honey locust has the more predictable response with a life expectancy not to exceed six years after initial signs.  Red oak mortality is highly variable and may die completely in months or linger for two decades or longer after initial signs.

Notice the use of the word sign!   A sign is tangible physical characteristic associated with a pest while the term symptom is used to describe a response, visible or otherwise, that the host presents.  This is an important distinction because symptoms almost always appear before signs.  For example, two Cedar elm trees in the same lawn may bud out at different times, with the sick tree leafing out later.  Another symptom of the weaker tree may be smaller and fewer leaves or leaves that appear to have a nutrient deficiency caused by some disturbance in the uptake of minerals from the roots.  If these symptoms are noticed, the tree owner should take a close look within the root zone for other evidence of problems.  At least 80% of all tree problems begin here.  A tree with a decaying root crown--that narrow circumferential band where the stem transitions into root tissue--is a candidate for removal.

Tree failure is unpredictable even Superman, whose x-ray vision should provide him some insight into the structural integrity of the woody fibers, would be wise to avoid placing a bet on a failure date.  Science can't, and probably never will be able to quantify all of the variables that determine the behavior of living organisms.  And when you're talking about two tons of rotten wood dangling over your shiny new automobile removal is warranted.  Besides, upon seeing all the bustle of a maintenance crew around your property, Mr. and Mrs. Jones across the street may begin to think your about to raise the bar a notch on keeping up with them.

When arborists discuss tree failure they usually do so in terms of risk percentages based upon known failure histories and their professional experience.  That's why its recommended that you hire an arborist with a little of that valuable experience under their belt.  Educated consumers should always ask a few questions prior to signing any contract.  That's right!  You need to plan on having a little paper to backup any agreements you make with this type of service.  Ask for insurance.  Don't just ask if they carry insurance  but ask for proof.  Check for professional certifications.  Arborists certified by a recognized organization such as the International Society of Arboriculture, have had to demonstrate some basic understanding of tree biology which is important in this case.  Understand there is a difference between membership in a professional organization and certification through that organization.  Finally, ask for a list of satisfied customers.  Most arborists expect you to check their references, so do.  Call some of their clients and ask them if they were satisfied with the services they received.  If they say no, run away!  If that crazy tree hugger gave you the name of a reference that didn't appreciate his workmanship, something ain't clicking upstairs.

Remember too that the cheapest bid isn't always the lowest in the long haul.  That pickup truck bandit that offered their services at a price too good to believe probably offered you a price that was too good to believe.  If he drops a one thousand pound limb on the corner of your home because he wasn't using safe rigging practices, who's gonna pay for the damages?

Stop pondering if your tree's ever gonna recover from the tumorous looking growth developing at its base and take some action.  Call a certified arborist.  In this case, waiting one more day for Ganoderma to vacate your property without a little assistance could kill you.

Monday, October 29, 2012

Root rotting fungi making an appearance at a site near you.

Be on the lookout for mushrooms at the base of your trees.  After months of drought followed by the recent heavy rains, the conditions are ripe for the development of mushrooms near the base of woody plants. These mushrooms, known as fruiting bodies, are signs that your trees may already be infected by root rotting fungi.  The most dangerous of these is the Armillaria species.  Armillaria fungi are particularly lethal to hardwood deciduous trees such as oak, elm and honey locust.  These fungi create a hazardous problem for homeowners that have large mature trees near their home.
The fruiting bodies of these fungi are commonly called honey mushrooms because of their golden yellow color, but there is nothing sweet about them.  As Armillaria invade the wood of trees to extract nutrients for their survival, it degrades the structural integrity of the tree.  This often happens without any visible signs of infestation until mushrooms develop.  By then, the risk of tree failure is a reality.  There is very little that can be done for the infected tree.  Removal is usually the best option.  If the tree is allowed to remain, there is some chance that it could topple over onto a target such as your home, your car, or worse.  Contact a professional arborist immediately if you spot mushrooms at the base of your tree. 
Tree removal in this situation is not a job for the do-it-yourselfer.  Once a tree has lost its structural integrity its direction of fall, even in a controlled environment, becomes unpredictable.  Certified arborists receive special training to help mitigate the irregular behavior of trees with internal decay.  The most important reason to contact a certified arborist is to identify the pathogen and determine the best control measures to be taken. 
The loss of one tree by Armillaria could spell the beginning of disaster for your other trees.  Very often, the spread of a plant pest is checked once it destroys its host but Armillaria thrives on both living and dead wood and can remain active in your lawn long enough to attack healthy trees.  If removal is warranted, it should involve as much of the root system as is practical.  Of course you don’t need to rip out your entire lawn but you will want to remove as much of the infection as you can.
One of the very best ways to ensure a healthy tree is to keep it properly watered during drought so it can defend against invading pathogens.  By collecting rainwater, you may be able to capture enough supplemental water to keep your all of your plants healthy even during drought.

Friday, October 26, 2012

Mulch that root zone

The roots of trees extend radially away from the trunk as much as 4 times the height of the canopy.  What! Does that mean a 20 foot tree has a mass of roots as far as 80 feet away?  Yes.  Well, of course that depends on a few things but generally speaking, that's correct.
Whats more, those roots that extend farthest away from the tree have a massive surface area relative to the anchorage roots closer to the stem.  The great number of root hairs associated with the finer ends of the roots system are thin and therefore extremely efficient at absorbing minerals, oxygen and water.  By the way, 80 to 90 percent of the roots of a tree are located in the top foot to 18 inches of soil. Not a mirror image of the tree canopy.  Thus the common term "root plate."
Check out the root system of the wind-thrown tree below.

Another interesting thing to know; roots form beneficial relationships with native soil fungi.  The roots spill nutrients into the surrounding soil and the fungi absorb and use them for growth and development.  In return, the fungi attach themselves to the root system and increase the absorptive surface area of the roots, allowing the roots to take up even more minerals for the tree. Cool stuff huh?  Well, some companies make and sell soil fungi, known as mycorrhizae, for mixing into the soil root zone with the belief that it will make your trees healthier and able to withstand adverse conditions.

Ok, so I stole a picture from Wiki, but it was the best example I could find of mycorrhizae on short notice.

I have an idea!  If most soils naturally contain some type of mycorrhizae, why not just improve the soil conditions of the roots zone to aid in the development of the fungi.  In fact, that's exactly what happens under a 4 inch layer of organic mulch.
The soil, or dirt if you prefer, under a thick layer of wood chips stays cooler and moister for longer periods than bare soil or soil covered by pebbles, rubber tires, or other inorganic mulches. Studies have also shown that, over time, the ability of soil to hold minerals and oxygen is improved under natural mulches.  Of course they need to be "fluffed" occasionally to avoid having a water-tight mat form over the roots, but that only takes a few minutes per year.  Organic mulches will even break down and provide some minerals to the roots, so when its time to replenish the decomposing mulch, simply stick a pitch fork into the existing layers, twist it back and forth a few times, then add the new mulch right on top.  This is what it should look like:
Yep, that's grass growing right through the mulch.  No need to kill the grass first, just mow it down and throw the mulch on top.  Notice that this bed of mulch extends all the way to the edge of the tree canopy and beyond.  It does little good to extend the mulch only a few feet away form the trunk since the most efficient roots are much further away.  If the grass annoys you, spray it with glyphosate, aka RoundUp.  Glyphosate is not active in the soil, therefore it wont get into the root system through the dirt.  It must contact something green on the plant in order to effectively kill it.  So spray the grass leaves and don't allow the chemical to drift onto the trunk or in the canopy.  Actually, if it gets onto the trunk, it probably wont do any harm but if it were my tree, I'd avoid letting it hit the trunk.

Monday, October 22, 2012

Right Plant, Right Place!

In the middle of a West Texas July, I drink copious amounts dihydrogenmonoxide.  I'm a native West Texan, so I poke fun at my oldest daughter, when she occasionally makes the summer trip from Cape Cod, Massachusetts to Midland for a visit.  She's accustomed to the cooler weather and higher precipitation of the Eastern seaboard.
For large woody plants such as trees, a similar visit would spell certain disaster.  Whoever heard of a sugar maple in West Texas.  They can't go indoors to cool off for a spell nor can they grab the garden hose at will to replenish their scorched foliage.  Even if they could, the salts in our water would pitch them into shock.  This over simplified analogy illustrates several reasons West Texas landscape plants need to be adapted or native to the region.  The most important of these is water.
The single most important limiting element that determines the survival of a plant is water.  Plants that are physiologically adapted to survive in regions of abundant rainfall will not perform well in the Permian Basin in the long haul.
No more common question is reaching the ears of arborists in West Texas right now than “how can I save my trees?”  We've seen the removal of hundreds of dead and dying trees for a couple of years now.  Few of these trees have been lost to insect pests and fewer still met their demise from fungal diseases.  Usually, these pests secondarily attack weakened trees. 
Trees that are maladjusted or non native to West Texas have been hanging on by tenuous threads of luck for many years and when the drought struck, their luck ran out.  One problem with planting a non-native landscape tree in the Permian Basin is that it typically has a high demand for water. 
Let’s consider trees in the true willow family.  Willows are native to a region in China that has a constantly damp clay soil and receives an average of about twenty-five inches of rainfall annually.  Willows are fast growing weak-wooded trees which are easily damaged in high winds and ice storms.  They can expect a healthy life span of about thirty years under optimal conditions.   After thirty years, they may hang on for many years in various states of decline.
Obviously Willows can be forced to grow in our poor soils and extreme heat as long as enough water is provided to supplement the thirteen or fourteen inches of precipitation we expect to receive every year.  But when the precipitation drops below projected amounts and supplemental irrigation is limited to two hours per week, trees with high water requirements such as willows, begin to agonize.  This same scenario is true for Silver maple, Mulberry, Sweet gum, poplar, Sycamore and a host of others not well adapted to conditions in the Permian Basin.
Now let’s consider another tree which is native to China that does well in the Permian Basin.  Chinese pistache is native to a region in western China that receives rainfall averages between 0.6 inches to 7.9 inches annually.  These conditions are similar to ours which is one reason Chinese pistache performs well in West Texas.  While it’s not native to Texas, it is adapted. 
If you already have a mature non-native tree on your property don’t give up on it just yet.  Many such trees can be drought hardened, to an extent, by slowly cutting back on the amount of water they receive over the course of several years.   The goal is to encourage the development of a root system that extends its reach further out into the surrounding soil.  Another way to keep these trees is to get more water to them by collecting and storing rainwater (see earlier posts) for use later.

Wednesday, October 17, 2012

What are Butter Beans? Mmm Mmm good! That's what they are.

Well, they're Lima beans and they're easy to grow. The South American native Phaseolus lunatus, a.k.a. butter beans, are grown in the spring by sowing them into healthy soils with ample organic matter once the soil temperatures have reached 55 degrees Fahrenheit.  Most beans are a little sensitive to soil temperatures and Lima beans will  not germinate in cold soils.

Plant the seeds about an inch deep and 10 inches apart.  Supply a couple inches of water per week but don't allow the soil to become waterlogged.  I'm a big advocate of amending garden soil with compost and one reason for this is water holding capacity.  Compost is nothing less than miraculous.  You can build copious amounts of beneficial organic matter of your own simply by layering leaves, lawn clippings and kitchen waste in a large pile in a corner of the yard.  By occasionally watering and turning this heap of decomposing material for a few short months, you'll generate a dark, rich, soil-amending fertilizer that's easy to work into your soil.

Butter beans mature somewhere between 60 and 90 days after seedlings sprout.  If you've never had them green then you're missing out on a real treat.  Harvest most of the pods while they're still soft but plump with the little buggers looking as if they want to jump onto your plate.  Allow a few to remain and mature on the plant until they become tan and hard.  These can be stored and used to start another crop later.

The Enchanted Cook (http://theenchantedcook.blogspot.com) posted the following recipe for two that she got while shopping at a farmer's market in her community:

1 Tablespoon extra-virgin olive oil
1 Tablespoon salted butter
1 1/2 cups fresh Lima beans
2 large cloves garlic, minced
kosher salt to taste
fresh cracked pepper to taste

Heat skillet to medium heat, add oil and butter.  Add Lima beans and cook, stirring occasionally for about 15-20 minutes.  Add garlic, salt and pepper and saute a minute or two longer.

Is your mouth watering?  I'm off to dinner!

Jeff Floyd
Texas A & M Agrilife Extension Agent – Horticulture

Tuesday, October 16, 2012

Rainwater Harvesting Viable Alternative in Arid Climates

Gone are the days when we could expect to apply endless amounts of municipal water to our West Texas lawns without forfeiting a little capital.  Some estimates place outdoor irrigation as high as sixty percent of total home water use with at least half of that being wasted by poorly timed or inefficient systems.   In the future you can anticipate hearing more about novel methods of providing water for your home and particularly your landscape.

One innovative method to supply supplemental water to your garden or landscape is to catch and store rainwater.  This little trick, called rainwater harvesting, can be simple or complex but all systems share some basic components.   For the simplest system you’ll need a surface to catch the rainwater.  The obvious choice for a catchment surface is the roof of your home.  A gutter system is essential for conveying the rain from the roof to a storage container.  Finally, a reservoir with a hose attached to a spigot at the base is a handy means of delivering the stored water to the location you intend to use it.  More complex systems may incorporate a timer with a pump connected to an irrigation system.  Another consideration is perhaps a treatment method to supply water for in-home use.

Avoid using a storage tank that allows light to penetrate through to the water.  Light will encourage the development of algae and microorganisms that will place a strain on your filtration system. If you must use a clear or opaque tank, paint it entirely with a dark color to deny the penetration of light.  Place a screen over the point where the rain enters the tank from the gutter to ensure that mosquitoes don’t have easy access to the water.

In your calculations, the shape or slope of the roof isn’t important, rather the footprint of the roof is used to determine the size of the catchment area.  If you are fortunate enough to plan the construction of your catchment surface, avoid materials that contain lead such as some wood shingles or flashing.  Standard composite shingles and metal roofs work well.

How much water can you expect to collect?  A 1,000 square foot roof will catch approximately 630 gallons of water from a one inch rain (rainwater harvested = square feet of surface area x inches of rain x 0.63).

Jeff Floyd
Texas A & M Agrilife Extension Agent – Horticulture