Newly emerging leaves on a red oak in the spring with male flowers

This spring season has brought with it an abundance of oak flowers or “tassles”.  I have noticed it on all of the oak species – live oak, post oak, blackjack oak, shumard (red) oak, etc.  They all have a bumber crop of male flowers this year. 

Oaks are monecieuos, which means that they have both male and female flowers on the same tree.  The male flowers are called “catkins” and hang down allowing the wind to pick up the pollen that they produce and send it to any receptive female flowers on the same tree or ones close by.  The pollen this year has been very heavy, coating cars and everything else outside that is exposed to the wind blown pollen with a yellow green film.

For allergy sufferers that are sensitive to oak pollen, the flowering should be over soon and the pollen  in the air should be decreasing over the coming weeks. 

I don’t know if the abundant male flowering will translate into an abundant acorn crop this fall.  The female flowers are much more inconspicuous and I haven’t had time to get into some trees to see if there is a coresponding abundance of female flowers. 

At any rate, the “worms” on your driveway are male oak flowers that have done their job of releasing pollen and are now dropping from the trees.

In our daily lives, we buy and sell many things.  We all want value in these transactions and the old adage is still true - ”you get what you pay for”.  This is true in almost every transaction and is true when it comes to choosing who will prune your trees.  This picture is of two live oaks for which the owner requested a pruning estimate.  The owner chose another company to do the pruning and they received the value that they paid for.  This post may seem like sour grapes, but I only want to point out that there is a difference in who gets into your trees.  We each have to decide what value we are willing to pay for.  There are a lot of tree cutters roaming the neighborhoods that will “prune” your trees for very little money.  Many of them do not have the slightest idea of what is good for the tree and what is good aesthetically.  All they know is to raise the canopy of the tree and strip out all of the lower internal limbs.  As you can see on these trees, there was no attention given to the density and weight at the end of the limbs.  These trees will now grow long and lanky limbs that will be prone to breakage and the suckers will come back with a vengence along the lenght of the limbs.  The health, beauty, and safety of these trees has now been compromised.  When you shop for pruning services, please make sure the provider is certified by the International Society of Arboriculture (ISA) and knows what they are doing in the trees.  Every cut on the tree has a purpose and each cut needs to be carefully considered before it is made.  Remember, “you get what you pay for”.  Trees are a valuable asset to your property.  Please don’t let the “tree cutters” near them.  You can verify ISA credentials by clicking here.

This brings up the topic of proper irrigation (or watering) of the your trees. It is very important to do it right. Many trees are killed with improper irrigation, mostly from over watering and keeping the top layer of soil saturated. The proper way to irrigate your trees is to provide a good, soaking irrigation that penetrates the top layer of soil and moves down into the layers underneath the top 3″. It takes about 3/4″-1″ of water in the root zone of the trees to penetrate deeply. This is a fair amount of water, equal to a good soaking rain. The trees should get this type of irrigation every week or ten days during the growing season, in the absence of rain. A drying cycle should occur between waterings. Tree roots (and all plants) need oxygen in the soil and the drying cycle allows for good gas exchange between the soil and the atmosphere. Without oxygen, tree roots die.

To accomplish good irrigation, without having half of the water run off and down the street, the irrigation should take place over enough time to allow the water to soak in. The best method for irrigation with an automatic sprinkler system is to set the controller to go through the zones multiple times. For example, if it takes your system 45 minutes of run time per zone to put out 1″ of water, then set the controller to go through each zone three times for 15 minutes each time. The first time through will break the surface tension of the soil and allow the subsequent cycles throught the zones to soak in well.

The goal of irrigation is to put a substantial amount of water on the root zone of the trees and then allow for a drying cycle before the next watering. Landscapes should not be watered every day or every other day. Watering once per week, with a good deep watering is very adequate for most landscapes. The trees will love it and so will your turf and shrubs. You will have less problems with fungal and bacterial disease issues and the plants will thrive with their roots down deep.

temperatures reached down to around 8 degrees and I’m afraid that any Fan Palms left from last year will not make it this year. The Fan Palms will survive short freezing periods above 15 degrees.

This is a picture of our neighbor’s tree that looked like this after last year’s freeze also.  So we’ll see if it survives. 

There is nothing to be done if the heart of the Palm froze.  That is where the new growth occurs.  The only treatment recommended is a fungicide sprayed into the center to minimize further fungal damage to already damaged tissues, but I am not convinced that it is worth the cost.  If you see  a little green start to show this spring, then your tree will probably make it. 

And remember…..North Texas does not have any native palms for one reason…….it gets too cold here occassionaly!  If you must plant palms, plant windmill palms as they can survive hard freezes down to about 5 degrees.  However, even the windmill palms have been knocked back some from this winter’s freeze.

• Trees reduce energy costs through shading of roof tops
• Trees add to to the market value of a property
• Trees add to our aesthetic enjoyment of our world which contributes to our overall mental and physical health

Trees on your property mean real dollars in your pocket over the long term, expecially in North Texas where the lack of trees is very noticed in the heat of the summer.  Investing in the maintenance of your trees will pay you dividends over the years as the trees bring you enjoyment, shade, beauty while you live under them and more money when you go to sell your property.

A recent report published by the US Forest Service’s Pacific Northwest Research Station provides some insight into the relation of trees to the value of a residential home or commercial property.  The report is titled,”Calculating the Green in Green: What Is an Urban Tree Worth?” Here are a couple of the key findings of the report:

• The presence of street trees increased the sale prices of houses in east Portland neighborhoods by an average of $8,870 and reduced time on the market by an average of 1.7 days.

• A tree in front of a house increased the house’s sale price by an average of $7,130. The tree’s benefits spilled over to houses within a 100-foot radius, increasing their combined value by $12,828.

This data confirms the results of a 1989 study in Austin, Texas published in the Journal of Arboriculture where the authors found that trees around residential homes added 13%-19% to the homes market value.

So, when you think of the trees in your yard, remember that they need regular maintenance so that they can give you back all that you ask of them.  And they do give us a lot, both in economic and aesthetic terms.

Looking at these pictures, you’d think they were taken somewhere in East Texas.  The first picture is a group of pines on Mingo Rd in Denton and the second is a group of stand of pines on Olympia Dr in Flower Mound near the Post Office.  The pines in Flower Mound are a remnant of the old Flower Mound tree farm that was on the land bounded by Morris, FM 1171, and old Rippy Rd before 2499 was extended north.

The point of these pictures is that the southern yellow pines (Slash and Loblolly) do well in the Lewisville area with the right soil.  There  are pines on I-35 near the Business 121 intersection on the east side.  There are not many left, but these were planted int he early 1960′s.  There is even a Pines Hotel still there to commemorate the pines that once filled that area.

If your going to plant the southern yellow pines, remember that they can get large and are a fairly messy tree to care for in your yard, dropping pine cones, needles, and limbs in abundance at various times of the year.  Don’t plant them if you have a pool.  The needles will constantly blow into the pool.

However, if you have space and want a piece of East Texas in your yard, Slash and Loblolly Pine will do well in the Lewisville area.

Spring is the worst time to prune your trees!  The trees are spending a lot of energy in producing the new spring growth.  Pruning them during this time of growth keeps the tree from recouping its “investment” in the carbohydrate producing factories – the new leaves.  Also, spring time is also active insect time and open wounds on trees can be attractive to certain pests looking for a place to call home.  Live Oaks and Red Oaks should not be pruned in the spring due to the activity of the beetles that can transmit Oak Wilt Disease. 

Wait until summer to prune your trees and better yet, wait until fall when the leaves have done their work and the tree has a good return on its investment in those leaves that will soon fall.

Winter is also a very good time to prune your trees.  Spring is the worst time and it can actually hurt your trees to prune in spring!

The pictures above are emerging Burr Oak and Red Oak leaves.  Taken on 3/31/2010.

Blackjack Oak in Flower Mound, Texas

Why do we prune trees?  Don’t they do well by themselves without our help?

We ask a lot of the trees that grow in an urban environment.  Space is limited, the soil has been compacted, soil nutrients are constantly being depleted, people damage them, etc.  Pruning is one of the management techniques that help a tree maintain its health and vigor in the space we are asking it to grow in.

Proper pruning is much more than cutting the lower limbs, or stripping out the interior suckers.  A tree is well maintained when professional arborists are allowed to work in the entire crown and only remove limbs and small branches that enhance the health and beauty of the tree.

Pruning is generally done for these reasons:

• Removal of deadwood
• Reduction off of buildings and other structures
• Reduction of interference with neighboring trees
• Reduction of weight to reduce breakage hazard
• Selectively thinning to improve air flow through the canopy
• Reduce transpiration rates to match root water absorption capacity
• Shape and beauty of the crown

Notice that beauty and aesthetics are last in the list.  A healthy tree is generally a beautiful tree.  We prune first for reasons of health and the trees beauty will become evident.  At times we may need to shape a tree that has lost a limb in a storm or for some other reason, but generally pruning is done first and foremost for the health of the tree.

Trees should be analyzed for pruning every 2-4 years depending on the species, the site, growth rates, etc.  Trees should never be pruned for pruning sake.  A professional arborist can properly analyze a tree for pruning, provide recommendations for the long term health of the tree, and specify what pruning (if any) should be done.

Staking of a newly planted tree should only be done if absolutely necessary.  If a tree is planted correctly in the native soil without additives, staking is often not necessary.  If a tree needs to be staked, here are some pointers that will help insure the long term health of the tree:

• Always use a broad strap or a soft hose around the tree trunk, never put wire or rope alone around the stem
• Don’t over tighten the wire so that unnecessary pressure is put on the stem of the tree.  Allow for a little movement of the tree.
• Use 2-3 stakes and wire placed low on the trunk if the root ball wobbles
• Use 1 stake and wire if the tree bends in one direction to help straighten the stem
• NEVER leave the stakes and wire past the first season.  The tree’s roots should be firmly established and holding the tree stable after six months to a year if planted correctly.
• Do not place stakes right next to the trunk of the tree or through the root ball.  Place outside of the root ball.

Trees need to bend and move in the wind to grow properly and gain a good taper on the stem.  If the tree is left staked, it will not get enough motion and the stem wood will not grow correctly.  Also, the tree will eventually grow around guy wires which produces a weak point in the stem and point of fungal infection.  Below are pictures of a prime example of trees that were staked when planted and the stakes and wire was left on too long.  Every one of these trees has a large canker wound and internal rot in the stem due to the negligence of not removing the staking after the first season.

These beautiful street trees have had their lives and usefulness cut short because the staking was not removed quickly from the trees.  Every tree in the row has the same canker and rot due most likely to the improper staking in their early life that caused the original wounds that have spread up and down the stems.

If you have trees that were planted too deep or have been covered by landscaping and fill soil, please call Tree Shepherds at 972-317-9598 for a consultation and remedy.