Tuesday, November 27, 2012

Tips for peak growth with Tree Tubes: Prune seedlings to a single stem

One of the most frequently asked questions from first-time tree tube users is:  "Should I prune my seedlings to single stems before applying the tree tubes, or should I gather the lateral branches and lower the tree tubes down over them?"

Unlike most things in forestry where foresters like be give lengthy "there's no wrong way to do it" replies, in this case the answer is absolute and unequivocal:  YOU PRUNE TO A SINGLE STEM BEFORE APPLYING THE TREE TUBE.

This seems counter-intuitive.  Then again, many things pertaining to tree tubes are.  But there are two very good reasons for pruning seedlings to a single stem before placing a tree tube on them:

1) Better tree form = better long term health.  In general, if you bend lateral branches upward to fit into a tree tube, those lateral branches will continue to grow up and out of the tube.  The result is a very acute angle between the lateral branch and the main stem.  The narrower that branch angle a) the weaker that branch connection is and the more prone it will be in the future to breaking under heavy wind and/or snow loads, and b) the more difficult it will be down the road to prune that branch properly.

Generally speaking if you put a tree tube over a single stem you get a single stem growing up through the tube and out the top.  You might get a few very small lateral branches in the tubes, but these tend to remain very small and are easily pruned when the tube is removed.

So simply from the standpoint of long term tree health Best Practice is to always prune seedlings to a single stem before "tree tubing" them.

2) Faster growth!  Fast growth is one of the primary reasons (besides protection from deer browse) that people use tree tubes in the first place, and pruning to a single stem before applying tree tubes flat out results in faster growth.

This is the part that seems counter-intuitive.  You get a nice big seedling from the nursery, complete with 2 or 3 good-sized lateral branches.  You plant the seedling and are just about to apply the tree tube.  You look at those lateral branches and think, "Cripes if I prune these branches I'm leaving 50% of the seedling I paid good money for laying on the ground.  Plus, doesn't it need the leaves on those branches to fuel more growth?"  Both perfectly natural thoughts and valid concerns.  I had the same thoughts and concerns myself, so I did a trial.  In my mind I thought I was trying to balance the better tree form I would get from pruning to a single stem with the faster growth I assumed I'd get by leaving the lateral branches in tact.  To my great surprise - and after 23 years tree tubes still never fail to surprise me - the seedlings I pruned to a single stem before tubing them not only exhibited better form, they also grew faster... A LOT faster!

I believe that there are two reasons for this faster growth, one obvious and one not-so-obvious:  a) All of the seedling's growth energy is channeled into a single stem, and b) removing the lateral branches and their leaves allows for better air flow/exchange in the tree tubes, and allows each leave to absorb more sunlight.

The importance of pruning to a single stem is illustrated perfectly in this video from Tree Protection Supply, a long-time distributor of high quality tree tubes (in fact there are several highly informative videos about Tree Tubes at Tree Protection Supply's You Tube Channel

As with so many things with tree tubes over the years, customers have pointed me in the right direction.  One grower I know in Mississippi not only prunes his seedlings to a single stem before applying tree tubes, he picks off all of the lateral buds leaving only the terminal buds.  Who am I to argue with his results?  Take a look:

(Click to enlarge)
This is a hybrid shumard x willow oak.  The acorns were gathered in autumn 2010.  They were not sown in nursery pots until July 2011.  This seedling was planted in autumn, 2011.  It was about 18 inches tall at the time.
This photograph was taken in September 2012 - after one growing season in the ground.  The green tree tube is 4ft tall, and the beige "tubextender" is 2ft tall and was added to keep deer from browsing the tree after emerging from the 4ft tree tube.  From there you can do the math and see how tall this tree is - after getting planted in late autumn 2011 as an 18" seedling - after just one growing season.  Amazing.

A lot more went into achieving that kind of growth (aggressive weed control, supplemental fertilization, etc.) and we'll cover those things in future posts. 

But a major factor in achieving this kind of growth is simply PRUNING SEEDLINGS TO A SINGLE STEM BEFORE APPLYING YOUR TREE TUBES.

Thursday, November 15, 2012

Absolutely astounding growth of oaks in tree tubes

This is unbelievable even to me - and I've worked with tree tubes for 23 years. 

This is a hybrid oak - overcup oak x white oak.  It was planted in March, 2011 as an 18 inch seedling.

(Click to enlarge)
This photo was taken yesterday, against a darkening Mississippi sky.  That tree is now 11 feet 8 inches tall.  (The tree tube is 4ft tall and the photograph is taken from ground level looking up.)
Let me be a little more clear, because it really is hard to wrap your brain around this:  In just two growing seasons this tree has grown 10 feet 3 inches since being planted as a seedling.

When I take a step back I shouldn't be surprised.  In fact these are the kind of results that I believe will become commonplace in the next decade.  It is the result of several factors:

1) Tree seedling planting stock is much, much better than ever.  Nurseries are selecting seed from superior trees, and are producing healthy, vigorous planting stock (especially stock growing in root-pruning pots) that is ready to "hit the ground running" with little or no transplant shock.

2) Trees - even oak trees - actually, especially oak trees - are inherently capable of remarkable growth.  Reaching that growth potential is simply a matter of removing the obstacles - the stresses - that prevent it from growing as fast as it might.  Those stresses include weed competition, drought, lack of nutrients, and of course animal browse.

3) Tree Tubes make it easy for growers to eliminate most if not all of those stresses:

> They shield tree seedlings from deer browse

> They make it easy to locate tree seedlings amidst the grass and brush, and protect them from weed control treatments that eliminate vegetative competition (thus making more moisture, nutrients and light available to the seedling)

> The shelter tree seedlings from drying winds, and capture and condense transpired moisture, returning it to the soil to be re-absorbed by the seedling.

In subsequent posts we'll be looking at how to achieve peak growth performance like this!