Gold Oak Press

Healthy Walnut Bark

Everyone loves a good mystery, except if you’re a farmer and the mystery is why your newly planted walnut trees are turning a strange color… The following account describes my father’s attempt to unravel a farming mystery:

Today Luis brought to my attention a disturbing development.  The bark of some of the new walnut trees that we recently planted is beginning to yellow.  Not a good sign.  

Yellowing Walnut Bark

The 1225 trees displaying this condition were planted several weeks ago under less than ideal soil moisture conditions, i.e. too wet.  A similar number of trees from the same nursery planted in January have sprouted and are growing satisfactorily.  Could the yellowing result from the soil conditions at the time of planting?(Why didn’t we plant all the trees in January when soil conditions were favorable?  Why did we resume planting in March before the soil had dried out sufficiently?  More about that in a later post.) 

When planting too wet, it is difficult to firm the soil around the roots without compacting the soil.  Eager to avoid compaction it is easy to leave air pockets around the roots, limiting good soil-root contact.  

But in the past we have planted satisfactorily under similar conditions.  Also, since the trees were planted we have had two substantial rains which have nicely settled the soil around the roots. 

Could the trees be displaying freeze damage suffered at the nursery before being dug? Remember those record temperatures we experienced in December?  

That seems like a reasonable possibility, but why didn’t the January-planted trees display similar symptoms?  Also suspect is the fact that the yellowing is occurring on the east side of the tree, suggesting that the damage occurred in our field since the tree orientation would not correspond to that in the nursery. 

But why the east side?   Stressed or damaged bark is very sensitive to sunburn even at low temperatures.  But sunburn usually occurs on the south and west side.  

Have sent pictures and wood samples to the nursery in overnight delivery.  Let’s see what they say.

This entry was posted on Sunday, April 18th, 2010 at 1:53 pm and is filed under Farming. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.