Coastal redwood tree not thriving
I planted this California costal redwood tree as a 6” sapling in a pot and raised it there until it was 2’ tall then transplanted it into my garden where it grew as much as 2-3’ per year for more than 10 years. It’s over 30’ tall now. I fertilize it with 10-10-10 pellet fertilizer a couple times a year. It was thriving. Then it started to not thrive. First the back to back blizzards of 2010 bent over the top until it broke, then new double tops grew. Second, in the last few years it’s been losing as many as 12 branches at a time when the winds are strong. They snap off where they connect to the trunk. Third, while the sunny South side of the tree always developed some brown needles over the Winter, now the Winter brown needle thing is all over the tree, not just on the South side. Fourth, there are now beetle bore holes in the trunk that just started appearing a few years ago. One beetle bore hole group I can see is in a horizontal line about 10’ up on the trunk. The tree used to have foliage thick enough that you couldn’t see through it. The foliage now seems thin. I always water the tree during times with less rain. The soil is clay like but in 1991 before planting the tree I had a bulldozer with a bucket dig up the whole area and added humus and other amendments. The tree thrived there for many years. Would you please recommend things to do to turn this California coastal redwood around and make it thrive again. Thank you. - Martha
If your tree is truly a California Coastal Redwood, (as opposed to a Dawn Redwood) you have had good luck with it.
We don't have good information about how it would do here, because it is native to the Pacific Coast, with pretty specific cultural needs, such as fog as a water source, that can not be met here.
Given previous limb loss, we hate to think how it may be fairing in todays weather.
The tree sounds as if it may be in decline.
In it's native range where it would be happiest, it doesn't seem to have insect or disease problems. Any chance your horizontal "borer holes" are woodpecker activity? See here: https://extension.umd.edu/hgic/woodpeckers-and-sapsuckers
We don't have good recommendations about what to do for your tree other than to suggest having a tree health expert, a.k.a. a certified arborist come to your property for an on-site evaluation of the tree.
You can search for a certified arborist at this site from the International Society of Arboriculture: www.treesaregood.org