Redwood trees are from our coastal regions which generally contain well-drained, neutral to acidic soils and maintain a cool, moist climate. In Kern County, we get very hot and generally have clay, hardpan, (especially in newer construction) and alkaline soils. In addition, redwood trees planted here do not have a forest of closely planted trees and a heavy floor cover of its own compost. These differences in our climate cause many, many problems. The following suggestions will help keep your trees alive and healthy.
1- Have your soil tested
Soil pH determines the availability of nutrients to the tree. If your pH is too high (alkaline) or too low (acidic) your trees will struggle or die. A soil test is always the best place to start.
2- Increase drainage
Redwoods need great drainage. Drilling holes and filling them with pea gravel is the best way to increase drainage and oxygenation around the roots. This should be done at the drip line every year, and as the trees grow this drainage area will expand with the tree. We do not use P.V.C. pipe in the ground because the holes in the pipe plug up quickly making them ineffective drains.
3- Deep root feed
No “tree” fertilizer will do much good if you just apply it to the surface (no matter what it says on the bag). Phosphorus and potassium will not move more than an inch through the soil. These are the two nutrients that provide rooting, fruiting, flowering, cell wall thickness, disease resistance and all around plant health. YOU MUST DEEP ROOT FEED TO GIVE THE TREE THE NUTRIENTS IT NEEDS!
4- Fungicide application
There are several fungi that can attack redwood trees. A healthy tree will be less susceptible than a weak one. If your tree has been diagnosed with a fungus disease, a fungicide application is an option. This should always be done AFTER adjusting your soil pH, drilling drainage holes and deep root feeding your tree. If needed, a fungicide application may be applied as a foliar and/or ground application. Ask one of our staff about the fungicide most appropriate for this application.
After you have done all of these things you should perfectly healthy redwoods, right? We wish it were that easy. Unfortunately, with the Bakersfield weather and redwoods will take a beating.
You should not prune the lower branches as these provide shade for the tree’s shallow roots and keep the bark from scorching. You should make sure these trees get plenty of water. Remember that water should pass the roots and move on into the water table. Drilling drainage holes, once again, at the beginning of summer is suggested.