Texas Ebony

Today is the last day of February and also the last post on perfect Zone 9 plants for the garden.  They must be green through our hellish summers and freezing winter nights and use little water to qualify.  Today's plant is the Texas Ebony.

Surprisingly, this tree is not utilized in many landscapes and yet is greener than any desert tree I've seen around here.  It packs a punch in the yard and makes for a nice green addition to your plant collection.  Little water needed once established, the Texas Ebony thrives on sun and heat.  It's a slow grower and can reach an amazing height(25 feet!) as you can see in this pic taken at the Tucson Botanical Gardens.  In fact, I didn't know about this plant until I had to deal with another Texan issue in my garden....Texas Root Rot!!!  I had to find a tree that would be resistant to this nasty fungal disease and discovered that the Texas Ebony was perfect for that area.  It has done well now for 2 years and has grown a couple inches.  The only drawback is that it's spiny and your clothes will catch on it so be careful handling this tree.   It grows 30 feet high and just as wide.
"Texas ebony tree grows quite well in Southern Arizona. Native to the Chihuahuan desert, this highly decorative tree is remarkably drought tolerant. Under ideal conditions, it grows to 30 feet tall with an equal spread. Medium green, compound leaves are arranged along thorny branches that twist and change direction repeatedly. Cream colored, fragrant clusters of flowers are produced from late spring to fall. These sweetly fragrant flowers are followed by large, dark brown seedpods. Texas ebony grows rather slowly, eventually becoming a small to medium-sized tree with a dense canopy.
Plant Texas ebony tree in the fall or spring in full or partial sunlight. It tolerates almost all soil conditions from deep, well-drained soil types to heavy clay. Water newly planted Texas ebony trees thoroughly, every 7 to 10 days, for the first year. In its natural form, Texas ebony grows a dense canopy to the ground. Prune in early summer to raise the canopy. Prune only a few side branches, until the crown is at the desired height. Wear protective clothing when working with this tree, as its stipular spines are very sharp. Water established Texas ebony trees twice a month in the summer and monthly in the winter. Falling seedpods create litter that may be a problem in high traffic areas."
Source: http://www.horticultureunlimited.com/landscape-plants/texas-ebony.html

We'll take another break from my journal notes and explore Arizona and around the world.  More from Las Aventuras tomorrow.......

The Canopy Connection

Happy New Year!!! As promised, I would get this writing finished before I begin teaching again.  It has been a wonderful time for me as I have been writing, volunteering, reading, and just thinking.  I've set my gardening projects up for the spring, and I can't wait to add more plants.  What will it all look like when finished?  The past week I made the purchase of 10 whiskey barrels that will contain the cactus garden for the property.  I have the cacti ready to plant which include agaves, prickly pear(the purple variety:), totem poles, and the list goes on and on. There is so much more to work on in the gardens in 2011.  However, I won't be posting as much in the following weeks with school starting up again. 

A typical Amazon morning in the forest....the mist reveals the various heights of trees.

Here is my own work below from the Amazon in 2008

Today's write is about the canopy we create above our heads in the garden/s. For many people, myself included, when we moved into our home, there were trees established on our property. Or for some, there was nothing.  I have a lot of space to work with here on the grounds and each space is considered its' own garden.  One of the spaces is named the fern garden because all the plants have fernlike leaves and when the sun hits the leaves, it filters to the ground nicely. Very few ferns can grow in our desert  and unfortuneatly, it's one of the plants that I don't try and grow anymore. I have luck with the asparagus fern and that does really well in Tucson(so some varieties are out there for the fern fan club just not the ones many people like:)  You need moisture in the air and that is something we don't have an abundance of.....so you have to think about things you like about the fern and find plants that have similiar qualities.  You can then  recreate that look about ferns in your own garden space. 

Let's get back to the canopy. A garden is not what we only create below us on the ground but one that we can also create in the sky above.  It's probably the trickiest art form of them all.  The inspiration that I have used in my own work is from the forests both here and abroad.  A homeowner must always use caution when planting trees closer together and near homes for a variety of reasons such as the roots damaging pipes, the foundation and/or the structure itself.  Again, precautions must be taken to prevent trees limbs from falling off and smashing onto the roof or side of the house.  I speak from experience on this latter issue.  Mesquites are fantastic trees but they can also be dangerous during a wind storm.  Branches, sometimes large ones, like to fall off and smash everything in its' path.  The key to this is pruning....not liontailing as I have written about before, but the sometimes necessary removal of a tree limb to prevent harm or damage to structures and/or people.  These are the technical aspects of creating the canopy....now let's look into the art of the canopy.

Once the homeowner has established what's acceptable to place in the space, s/he can begin to design the air space above.  My particular fern garden will allow for light and wind to filter through like a southern garden that has willows.  Standing in the rain forest, looking above, you see birds and monkeys and a million other things living amongst the tree tops.  While this is the desert, it doesn't mean that life doesn't exist....quite the opposite!  We have so many birds here(see my previous post on Christmas in the Canyon).  I had to look at tree shapes and at their maximum mature heights to see how they would all interlock together.  Some trees are tall and narrow while others are rounder and shorter. Then you sketch on a sheet of paper the projected image of how the sky garden will look.  Don't be discouraged if the growth doesn't happen overnight. And you may have setbacks!  Remember my Chinese elm that croaked due to Texas Root Rot?  I researched and found a resistant Texas Ebony to replace the tree.  While slower growing, it will eventually connect with the other trees.  Some trees will shoot high into the sky and be narrow while others will create the "lower-to-the-ground" look and the mid level trees will fill out the center layer of sky space.  When put together, it will be the equivalent of a desert-like amazon rain forest....except all xeric:)  For this particular garden, I used a mesquite, the desert fern tree(lysiloma), the chitalpa, the jacaranda, the eucalyptus tree, the Texas ebony, and finally the Arizona Ash.  That's a lot of tree so figure out who your shorter trees are, then your middle layer trees and finish with your emergents or taller trees.  And like a puzzle, they will all connect in time:)

In the desert, naturally, things are spread out because that's how it works here......however, there are also oasis islands where a person will find these drawings a reality.  Again, observe other places and plan plan plan.  Another garden that I am working on is the tropical fruit garden which is opposite the fern garden.  It will have a different feel but one that will utilize the same ideas with fruit trees that do well here in Tucson like the fig, guava, loquat, etc. This blog is a record of all the things that inspire and create El Presidio Gardens.  A person can't say that just one thing creates a garden because there is so much history, art, observation, technical information......and just knowledge that goes into planning something special like this space.  These pics were pulled from the internet to demonstrate what I am writing about......but you can see in the video from yesterday,  the idea that I am working on from the post called "A Cold End".  Most of the trees have lost their leaves for the winter but you'll definitely see the eucalyptus. I look forward to the new year with the new projects...stay tuned for more in January. There's always something going wherever you may be.  If you're in the North, you're planning and looking through gardening books and if you're in the warmer areas, your protecting plants from frost and beginning your projects before the intense heat.  Wherever you may be....Happy Gardening in 2011!!

Texan Issues in the Garden

A while back, I posted something on Texas Root Rot killing my beautiful Chinese Elm over a year ago.  During my research, I found several suitable replacement trees for that area that were resistant to root rot. If you have had Texas Root Rot, you know that you cannot plant any trees that are susceptible to this disease again in that area.  It's just a natural fact here in Arizona that the fungus lives.  It's not everywhere, but it exists.  I've met a lot of people that have had this happen.  The tree will be beautiful one moment and in the next, the leaves will be dried and curled....they won't fall....they'll just hang on the tree.  At this point, the tree has suffocated and died.  The good news is that there are plants that will grow in these spots that have Texas Root Rot....and one of them is the Texas Ebony tree.  How appropriate!  Texas Ebony for Texas Root Rot:)  The elm was green and beautiful and it crushed me when she died. But from my research, I found that Texas Ebony, which is underused here in Tucson, was a perfect fit for that very green spot in my garden. Two cons about the plants....it's slow growing and it is thorny.  The pros are that it is so green and xeric that it's just plain ol' surprising that it can grow in the dry hot desert.....but it does.  It's from the legume family which means that it will add nitrogen back into the soil and that is a good thing for your other plants. Two plants I recommend for xeric gardeners, from Texas of course:), are the mountain laurel and texan ebony.

For more information on Texas Root Rot and suggested plants for these infected areas click on the link below for more information....

http://aggie-horticulture.tamu.edu/archives/parsons/publications/cottonrootrot/cotton.html

Cotton root rot, caused by the fungus Phymatotrichum omnivorum, also is known by several other names such as Phymatotrichum root rot, Texas root rot and Ozonium root rot. It is one of the most destructive plant diseases and attacks more than 2,000 species. However, either the fungus infects but does not kill monocotyledonous plants (grasses, etc.), or these plants are all highly resistant. In Texas (and Arizona), the disease is economically important in cotton, alfalfa, ornamental plants, and fruit, nut and shade trees. The fungus is prevalent in calcareous clay loam soils with a pH range of 7.0 to 8.5 and in areas with high summer temperatures. Therefore, the disease is limited to the southwestern United States.

Phymatotrichum root rot has been reported in Texas counties from the Red River to the Rio Grande and from Tom Green County to the Neches River.
Disease Symptoms
Disease symptoms are most likely to occur from June through September when soil temperatures reach 28oC (82oF). The first symptoms are slight yellowing or bronzing of leaves followed by wilting. Plants die suddenly after the first symptoms of wilting. Leaves remain firmly attached to the plant. Affected plants die suddenly, often after excellent growth. Large trees and shrubs may die more slowly.

Usually roots are invaded extensively by the fungus by the time plants have wilted. When roots are pulled from the soil, root bark is decayed and brownish, and wooly strands of the fungus frequently are apparent on the root surface. Affected plants pull from the soil with little effort.
Under moist conditions, sporemats sometimes appear on the soil surface. These mats, 2 to 16 inches in diameter, are first snow-white and cottony and later tan and powdery. On large roots and tubers, there are numerous small, cushion-like sclerotia or resting bodies about the size of a pinhead. At first they are light tan but later appear dark and warty.
The fungus generally invades new areas by continually slow growth through the soil from plant to plant. Occasionally, it spreads more rapidly on the roots of infected transplanted plants. The fungus can survive in the soil for many years, and often it is found as deep in the soil as roots penetrate. Affected areas often appear as circular areas of dead plants in fields of infected crops. These areas gradually enlarge in subsequent years as the fungus grows through the soil from plant to plant. Infested areas as may increase 5 to 30 feet per year.
Hyphae and strands. The fungus produces root-like strands (rhizomorphs) that grow through the soil until they contact the descending plant roots. Strands surround a root and grow toward the soil surface. Immediately below the surface, the fungus proliferates around the hypocotyl, producing a cottony, mycelial growth. Below this mycelium, the bark is destroyed, and the fungus fills the vascular tissue of the plant. Following death of the plant, sclerotia form in the strands
Plant barriers. This technique consists of planting resistant species around an infected area. These barriers either exclude or limit the spread of the pathogen. This technique assumes that the barrier plant does not harbor the pathogen in its root system. Make ornamental plantings of cotton root rot-susceptible species with isolated plants or groups of plants rather than in continuous rows as hedges. When the disease occurs in an ornamental planting, replace diseased plants with resistant species.
Fertilizer applications. To reduce root rot, apply fertilizers high in certain nitrogen forms. When nitrogen is applied as ammonia in a manner to fumigate as much soil as possible, research shows a reduced incidence of root rot.
In some cases, valuable ornamental plants and orchard trees have been treated successfully even after root rot infection has taken place. First prune the tree (or shrub) back and build a circular ridge (equal in diameter to the top of the plant) of soil some distance from the trunk. Work 1 pound of ammonium sulfate into the soil for each 100 square feet of surface within this ridge. Fill the area within the ridge with water to a depth of about 4 inches. Repeat the treatment and watering after 5 to 10 days. Do not apply more than two treatments in the same season. Following this treatment, water frequently to prevent drought injury. Acidifying the soil with sulfur around susceptible trees or shrubs may help delay or prevent root rot infection in areas where the disease is prevalent.
Resistant varieties. Development of resistant plants using conventional breeding concepts, has been difficult due to the pathogen's wide host range. However, the following list of woody and herbaceous plants has shown resistance or tolerance to cotton root rot and should be considered by the homeowner where the disease is prevalent. The hardiness zone is given for each woody plant listed. Check the map to determine the zone in which you wish to use the plant. Use any plant with that zone number or a lower number. Plants with a higher zone number usually will not be hardy in that area. Check the list for size and foliage type to aid you in selecting the plants best suited for your particular purpose.