We tend to take tree roots for granted. Being hidden out of sight, and for the most part silent, a tree’s roots are often overlooked (literally), or misunderstood. Remember, half of your tree is, or should be, underground.
A tree’s root system has a number of functions, some of which will take a fair amount of imagination to appreciate! How does a huge, leaning tree remain standing for hundreds of years? How can an ancient oak survive in a seemingly bone dry savannah? How does a tree in downtown Ashland eke out a living with absolutely NO mulch, NO irrigation, NO nuthin’? A tree’s roots have in no particular order, five major functions: to anchor, absorb, store, transport and breathe. What a job!
If you deny the tree’s roots the ability to perform any of these these functions, failure is sure to follow…
If you were to tell someone that you have an old oak tree on your property that has a root system, if carefully taken apart and laid end to end, would circumnavigate the earth at the equator, you might not be far off!
Scientists have found over 6000 (yes, six thousand!) miles of roots in a cubic inch of soil from a single ryegrass plant! Imagine, if you will, the totality of the mass of the root system of a mammoth redwood?
In order for roots, and a tree to survive, remember WETS: Water, Elements, Temperature and Space.
When a tree (and its root system), gets bigger as it matures, the irrigation regime changes as well. Amazingly, I see a drip emitter, or two, right at the base of mature trees all over town! There are NO absorbing roots at the base of a mature tree, or at least there shouldn’t be…
Roots are lazy for the most part, and will take the path of least resistance whenever they can. If you irrigate often and shallow, you will have a myriad of surface roots, and the opposite is true as well, deep and infrequent will make for a strong, well-formed root system.
How then, do trees survive in the forest? That is magic! The real bugaboo, is asking a tree to survive in a lawn. You can water a lawn every day, and properly mulched, a newly planted tree will need a drink about once a week or so, a little more often if subjected to extreme heat or drying wind…
I like to mulch about twice drip line or so when possible. Cooling the encompassing soil around the roots will facilitate their journey through the soil strata. Mimic a forest environment, and your tree will be happy!