Over my 30 year career, I have observed extremely high cone production on spruces in concert with the bottom branches dying from the bottom upward. My opinion is that these symptoms were a direct result of extreme stress exerted upon trees that had been transplanted as balled and burlap trees or spade truck trees. Poor nutrition, planting too deep, girdling twine or girdled roots are to blame. The worst part of this story is that improperly planted trees dies several years (5-15) after planting and absolutely after the warranty expires. As a tree pathologist and consulting arborist, its my job to determine the stress factors upon trees in there present location and make recommendation to correct.
Back in 2009 I was called to diagnose problems with three hundred-fifty (350), 10' tall blue spruce outside of Jackson Hole. Two different companies had planted trees on this property in the same season.
Company A: Three hundred twenty five (325) had been planted 8-12" below grade. the bottom branches of these trees had to be removed by the landscaper just to get the soil back in the planting hole. The cages were still attached, burlap was still covering the top of the ball and was still wrapped around the trunk secured there by the nylon twine. The burlap had not begun to decay and the combination of burlap and twine all below grade with soil microbes eating away at the portion of trunk bake buried was beginning to girdle the trunk. These trees all had different stages of root, basal and vascular disease's. These stressed trees (325) had been producing bumper crops of spruce cones for 3 years straight prior to my arrival and the tops were bent over due to the weight with some 50-70 cones each year being represented.
Company B: Twenty five (25) trees where planted at the proper grade. The burlap was removed back to the edge of ball and they also removed the twine. These 25 all had maybe 15-25 cones each.
After remediation and implementing of a proper health care program of all trees in question, with the exception of a few that were just too far along to save are now healthy and produce alternately, a light crop one year of 20 cones and a bit heavier cone crop the next year of about 30 cones.
My take on this situation and many other sites is that stressed trees that have been transplanted improperly may very well begin to produce a mega cone crop as it senses it's mortality. Healthy trees on the other hand produce but a bucket full each year.
As you inventory your spruces or a friends trees, which ones don't look like the others? On average as you scan the landscape, which individuals trees are loaded with cones? They may just be the tip of the iceberg and the others may just be a year or two from having the same problems. In this situation, sooner is better. For every year it took the tree to become visually stressed, plan on the same amount of years to get them back to showpiece condition.
Until next time...
Until next time...