Saturday, December 7, 2019

Fall, Winter Storms vs. Your Trees


40-50 mph winds + several inches of rain over a few hours = the recipe for a typical winter storm in much of California. 


TV news crews rush to the most photogenic damage during these rare occasions: downed trees, usually leaning against a house or crushing a car.

Without the correct care of the trees on your property, winter storms and trees will not get along. Most susceptible are the trees that keep their leaves year round, such as eucalyptus and camphor, along with the conifer family: pines, firs, redwoods and cedars. All that mass of greenery acts as a sail in a heavy wind, bending trees at ridiculous angles. Another cause of winter tree failure is crown rot, which despite its name, refers to the deterioration of the root system near the base of the tree. Combine that with a couple of inches of rain onto already saturated soils, and you have tree roots heaving towards the surface, leading to these pictures popping up on the TV news:


If this is the view from your window, the day after a major rain and wind storm is not necessarily the best day for the gardener to tackle the hazardous task of cleaning up the remnants of trees, shrubs and other plants that took a beating. If wind and rain is still in the forecast, the prevalence of slippery conditions and the chance of more falling debris should limit your cleaning chores to dragging broken branches away from the scene of the crime. It is not a good day to be climbing ladders or scrambling into trees while balancing a chain saw. Leave that to the professionals.

Arborists offer this good piece of advice for those surveying the fallen aftermath of a major storm: Limb failure is largely a product of poor tree maintenance over time. Take care of your trees, or they may take care of themselves in ways you won't appreciate.
According to the University of California publication, "Inspect Your Landscape Trees for Hazards", a nice day in autumn (or winter, spring or summer, for that matter) is the time to take an inventory of any possible future tree damage before you, your house or your car becomes the next victim of a falling tree or branch.

Leaning Trees: Are your trees not as upright as the result of recent heavy winds? Can you see newly upheaved roots or soil around those trees? Then, immediate action is required: call in a professional, certified, bonded and insured arborist to do an onsite inspection and offer a solution (find one near you at Newly leaning trees are an imminent hazard. 
If you have a tree that has leaned for a number of years, that tree can still be a hazard during wet, windy weather. Taking periodic photographs can help you determine if a greater lean is developing.

Multiple Trunked Trees: This co-dominant condition can result in breakage of major tree parts during storms. Usually, these trunks are weakly attached. Inspect the point where the two trunks meet; if you see splitting beginning, call in an arborist.

Weakly Attached Branches: Trees with many branches arising from the same point on the trunk are prone to breaking during wind storms. Prune out any split branches. Thin out multiple branches.

Hanging or Broken Branches: If you see storm damaged branches hanging from the tree, remove them as soon as possible. This includes removing any completely broken branches that may be resting elsewhere in the tree's canopy.

Cracks in Trunks and Branches: Measure the depth of any cracks with a ruler. If those cracks are more than three inches deep, call in an arborist to determine the best course of action.

Dead Branches/Trees: Branches or entire trees that have completely died are very likely to come tumbling down in a storm. Dead branches are most noticeable in the summer when the tree is in full leaf.

Cavities and Decay: Large, open pockets where branches meet the trunk, or at the base of the trunk, can mean big trouble. The presence of mushrooms on the bark or on exposed roots may indicate wood decay. Call in an arborist.

The Arbor Day Foundation website has this animated guide to proper pruning techniques.

Also: Tips for Hiring an Arborist. 

And, an illustrated guide for pruning large branches (which are branches that are greater than the thickness of your thumb): the three-cut method.

Saturday, September 28, 2019

October Garden Tasks

October is an outstanding time of the year for gardens and gardeners. The soil is still warm, but air temperatures are much more pleasant. New plants love the warm soil; gardeners love the 70-degree days. Here are a few garden tasks that are perfect for this month in the Central Valley, East Bay and low foothills of Northern and Central California.
Chinese Pistache

Gingko biloba
Early October:
• This is a great time for planting new trees and shrubs, especially ones with outstanding fall foliage for our area. Good specimens include the Chinese pistache, Washington hawthorn, Japanese maple and Amur maple for typical lot sizes; the "October Glory" red maple, ginkgo, red oak and scarlet oak for larger lots.
• Reduce the frequency of lawn irrigations to once a week. Turn off the sprinkler timer when it rains.
• Feed roses one more time to keep the blooms coming through the fall.
• Don't let your summer vegetable garden go bare. Plant a winter cover crop such as vetch, fava beans or clover to help replenish the soil with nitrogen.
• Vegetables to plant from seed now include radish, spinach, and peas.
•Dethatch, aerate and overseed bermuda grass lawns with rye grass to keep it green all winter.
•Cool season lawns, such as the popular fescue blends, are putting on a spurt of growth now. Mow often so that you are never removing more than a third of the total height of the grass blade.
•Nurseries have a good supply of winter blooming annuals in supply this month; also, select onion sets now for your vegetable garden.
•This is a good time to plant ground covers. This will give their root systems a chance to get established for their burst of spring growth.
• Dealing with the possibility of drought: Looking to upgrade your sprinkler control system? Choose one that will turn your sprinklers off when it rains. Also, newer systems will adjust the run times based on the season as well as soil moisture content.

Tomato Hornworm Cocoon
Lawn Aerator, Dethatcher

 • Tomato hornworms are going into hibernation in the soil beneath your tomato plants. Dig down about four inches and discard their cocoons, which resemble two inch-long, reddish footballs.
• Mid-October is your last, best chance to dethatch, aerate and overseed a sad looking lawn for the year.
• Despite the cooler temperatures, your lawn and garden still need about an inch of water a week. Unless the rains come, keep your automatic sprinklers operating.
• After you've cleared out the dying summer vegetables, improve the soil for next year's garden by checking the acidity/alkalinity with a pH test kit. They’re available at just about every nursery.
• Putting on a garden show currently: “Autumn Joy” sedum, with its reddish-pink, umbrella-shaped flowers. This herbaceous perennial gets about 18 inches tall and wide.

“Autumn Joy” sedum

Sasanqua Camellia

Late October:
• Scatter and plant tulip and daffodil bulbs outdoors for a more natural look.
• Add some indoor color for the upcoming holiday seasons by planting bulbs now in containers.
• Now in bloom: the sasanqua camellia. This variety can take more sun than the japonica camellia, which blooms in late winter.
• Protect rhododendron and azalea roots during the winter by adding two or three inches of mulch beneath those plants.
• Available now at nurseries: colorful winter blooming annuals such as violas, calendulas, stock, Iceland poppies and snapdragons.
• Temperatures dipping down below freezing can occur here in early November. Prepare for that possibility by moving frost-sensitive potted plants next to the house or indoors.
• Row covers, hot caps, and water-filled containers surrounding young vegetable seedlings offer these plants a warmer nighttime environment.
• Prepare for the rainy season by knocking down watering basins around trees.
• Wait until we get two or three rainstorms in a row before scattering wildflower seeds. In the meantime, remove the weeds in that area.