I don't know man. An old tree like that and given climate may yield extra lifespan from higher fertilizer concentrations poured into augured holes 2-3' deep beneath the dripline in a staggered pattern 1-meter apart; 1/2 a US Cup per hole, done annually or biannually, during mid to late Fall.

I'm not a certified arborist but I did stay at a Holiday Inn once so that qualified me to say that in a previous job I did do applications on old trees showing symptomatic age issues just like yours. When you're finished auguring and fertilizing, return with a rake and backfill the holes.

Fertilizer provides more plant material for photosynthesis and boosts their immune system to help ward off pests. Of course everything no matter what it is carries with it a death sentence the day it begins life... an all purpose fertilizer is what you use....

Congrats on your concolor.

Much regards,

Dax

Nurseries SELL A. concolors here in central MD, but I don't see many large ones around. My climate is (very) slightly drier, slightly more continental than yours (probably generally cooler summer nights), so the chances of one growing well here are probably somewhat higher.

Another conifer that struggles here is Pseudotsuga menziesii. A friend of mine in Cecil County has one that is about 25' tall. It's got a full enough canopy, but has a sickly appearance to its foliage, & appears to only grow about 8"/yr.

"so the chances of one growing well here are probably somewhat higher. "
Agreed.

"Another conifer that struggles here is Pseudotsuga menziesii."

Yeah, the best looking Douglas Fir I've seen in the DC area (never noticed one at the arboretum but I suppose there is one) was at Tyson's Corner, on a steep grade abutting a parking lot. Probably drained very well due to both the slope and the fact that the fill might have been chock full of rocks, aggregate bits or sand. With all the reconfiguration around Tysons in the past 20 years I doubt it's there anymore. BTW Tysons's is the highest elevation in Fairfax County - 500' - and probably has reasonably cool nights when we are under zonal flow in the summer.

With all these various non-coastal western conifers the main risk on the east coast is drowning, probably. The Taiwanese Pseudostuga wilsoniana, OTOH, is growing about 18" a year. An exception is Calocedrus decurrens which seems to relish all the rain it can take as long as it has well drained soil.

Gardener365 I have had that thought, but I really think an aggressive fertilization regime will let some pathogen set in.

This post was edited by davidrt28 on Mon, Sep 2, 13 at 0:17

There's no point in placing dry fertilizer in 2'-3' deep columns. Scatter it over the ground around the tree instead - if there is a specific indication fertilizer will be helpful.

David, I've posted this before -- the "biggest" concolor I've seen, at a campus in west MD. Looks fine -- it's actually double trunked but you can't see it. I'd think the DC National Arb would have some older ones, but I can't remember.

My own planted concolor grows painfully slowly...

Thanks beng. Good looking tree. Why the secret, or do you not remember? When you say western MD, do you mean somewhere WAY out there, like Frostburg State which is fairly elevated and has cool nights - almost as cool as southern England's - or Mt. St. Mary's near Frederick?

David, just can't remember any of the firs. :) I'll try a web-search for concolors at the DC Arb.

The concolor's on the Jr College campus in Hagerstown. It's up on a rise, so the drainage is good. I've seen a couple similar concolors near Cumberland, which also has some surprisingly nice Blue Atlas cedars about 30 yrs old -- 50' tall.