Ponderosa Pine issues

[Montana_Sam]

Hi all

I recently built a small house pretty close, maybe 25', from a large 4-stocked Ponderosa Pine, (western yellow to some). The excavator guys piled up the back-fill around the base of the tree, and then smoothed everything out after construction...the feeder roots have most definitely been jeopardized. 3 of the stocks are doing very well, lots of lush green new growth, full crowns looking healthy. One stock, perhaps 34" dbh, has shown some significant crown thinning in the 2-3 years since construction...needles dropping throughout the seasons, cones dropping when the other stocks are not, and the tip top is still lush and green, but it is struggling.

Any advice? I have spread a thin layer of compost and loosely planted alfalfa in hopes of rejuvenating the compacted soil, and I give the tree some extra water during July and August (this is Northwest Montana, drought during late summer is common).

thanks

 

[Montana_Sam]

Here is a photo of the tree during construction...the big one on the right. At the time of the photo the tree was doing just fine, no noticeable decline. You can see the pile of backfill at the base of the furthest stock...this is the stock that is declining.

 

[Dbodave]

I haven't had any luck slowing or reversing pine decline. Simply mulching the area will prevent further compaction and soil will de-compact over time (years). Some people also do air spade work that can loosen the soil without damaging roots. It's not my area of expertise although the company I work for is moving in that direction for some jobs, mostly to excavate root flares to get at stem girdling roots on smaller size trees. It's also a good opportunity to ammend the soil with organic matter and carbon that can help promote micorhizae and retain soil moisture better.
It's good that you are watering. How much? I would put the hose on full blast for an hour or two once a week in droughty weather.