Wednesday, June 26, 2013

How to kill an oak tree #973: Killing me slowly with backfill

God, this is disheartening.  Stopped for gas in Paso Robles, CA on Friday afternoon (Paso Robles = Oak Tree Pass in English - the most recent and perhaps most ill-fitting language of the area) and I saw this:

(Click to enlarge)
This tree is dying. It is a massive California white oak/valley oak (Q. lobata) with a crown spread of about 80 feet or so.

And therein lies the problem.  A crown spread of 80 feet equals a root system spread of more than 80 feet.  But when the gas station was built the grade was raised around the tree, save for a 10 foot diameter dish right around the trunk that was left at the original grade.

The grade wasn't raised by much - 6 inches in most places, maybe 12 to 18 inches farther away from the tree.  But that's enough, especially if (as I suspect) construction equipment compacted the soil in the drip line root zone.  Roots that were inches below the surface poised to swallow precious moisture from the rare Paso Robles cloudbursts and which had plenty of pores of air space in which to breath, are now several times farther from the hard packed surface, with no air space to breath and no water to drink.

The sad parts are:

1. Someone actually made an effort to help the tree by leaving a dish at original grade.  They just didn't know (I prefer that to thinking they knew and just didn't care) that the most valuable roots are way out below the drip line or beyond.  They didn't know that even a minor change in grade, especially when combined with soil compaction, can suffocate the fine feeder roots that are the lifeblood of any tree, no matter how huge.  The knowledge gap on construction sites is still, after all these years, immense.

2. The tree is dying so slowly - this gas station was built several years ago - that by the time it dies no one will connect its death to the damage that was done during construction.  Instead its death will be blamed on old age (Ha! This tree would live another 150 years left to its own devices) or on the insect and/or disease pests that aren't the primary cause of death but are only the secondary and opportunistic beneficiaries of the tree's stress and struggles.

The third and saddest part?

 (Click to enlarge)

3.  There's another tree right next door behind a car dealership that is dying in exactly the same slow way.

Sigh.

Obey the drip line people.  And if you're not going to - or can't - obey the drip line, then do the tree the honor of harvesting it and putting it to use, rather than leaving it to die a slow, drawn-out death that will leave its wood rotten and its spirit ruined.

Thursday, June 6, 2013

Slow growing oaks #463

I spend much of my time selling tree tubes to commercial pistachio, almond and pecan growers, helping them shave a precious year or two off the time from planting to first commercial crop, while reducing the inputs of water, labor and chemicals needed to reach that point.  When planting a new pistachio orchard in the San Joaquin Valley, under drip irrigation, fertilization and with a kajillion degrees days (OK, that figure is approximate) per growing season, getting a commercial crop in the 5th growing season is considered very good.

Acorns, on the other hand, could never be a commercial crop because oak trees are so "slow growing" and because they take at least 15 to 20 years to produce a crop of acorns... right?

Wrong.  Take a look:

 (Click to enlarge)

This is a sawtooth oak tree (Quercus acutissima).  It was planted in Georgia in the spring of 2008 as an 18 inch bare root seedling.  It is now about 30 feet tall (I'll post a photo of the whole tree soon).  Sorry the foreground is a bit blurry - turns out I don't do my best photographic work with chiggers digging into my skin.

The red circles in the photo mark the locations of acorns.  Yes, acorns.  This is the 6th growing season for this tree and it is going to have a very sizable crop of acorns.

This is not a specially selected sawtooth variety - just a standard "bed run" bare root seedling.  It wasn't watered.  It wasn't fertilized.  Weed control has been sporadic at best.

With even the slightest modicum of genetic selection and 1/1,000,000th the amount of plant breeding that has gone into corn, and with only slightly more intense growing practices, I guarantee we could have oak trees producing a sizable crop of acorns in the 4th growing season, if not sooner.

Tell me this shouldn't be the basis for a viable "new" (and yet very, very old) crop.