Integrity Tree ServiceIntegrity Tree Service

Prepare Your Trees for Summer Part 4

Rain and Wind Dynamics

 Fallen Euc

Wind forces act upon trees in unique ways depending on the distribution of foliage throughout the entire tree crown as well as along individual branches. Thinning cuts as well as reduction cuts help reduce the drag (wind resistance) on the tree canopy and lower the height of the pressure center to larger diameter wood. To prepare your trees for summer winds, a combination of both types of pruning is needed but especially reduction pruning. Research has shown that reduction pruning to alleviate end weight is the best type of pruning to decrease risk of tree and branch failure.

A big mistake is to over-thin trees with the idea that this makes them safer. There is an unacceptable pruning technique called Lion’s Tailing that removes an excessive number of smaller branches from a tree’s interior at the neglect of the outer third of the crown. You’ve probably seen these sorry, stripped-out specimens on your street. The wind blows through their lower crown but is concentrated now in the lion tails of heavy foliage that flag in the wind and often break. Properly thinned branches have an even distribution of foliage along the entire length of the branch. Consequently the force of the wind is now evenly distributed along the length of the branch, transferring that force to the base of the branch where the diameter is greater and it can better support the branch movement.

Tips to prepare your trees for summer storms:

  • Plant trees in groups. They buffer the wind from their neighbor trees.
  • Turn off your water! Excessive irrigation prior to a wind event can lead to entire tree failure. So turn off your watering system when a major monsoon storm is coming.
  • Don’t Lion Tail your trees.
  • Concentrate pruning in the outer third of the canopy using primarily reduction pruning techniques. Proper reduction pruning requires special skill to avoid making heading or stub cuts. If your trees are large or have excessive end weight, consider hiring a Certified Arborist to help out.

If you prune your own trees, consider attending one of my upcoming pruning classes. I will be teaching a class at the Desert Botanical Garden on June 22nd. Click here for more information or to register.

Enhanced by Zemanta

Leave a Comment

Prepare Your Trees for Summer Part 3

Irrigation

To prepare your trees for summer, there is nothing more important than proper watering. Doing it well can be a challenge in the desert, but the following tips should help.

Soaker Hose Dripping

  • The first secret of watering desert trees is to know your how well your soil holds water. Because different soils drain differently, they require different amounts of water and different watering frequencies. You can use a soil probe, available at most good nurseries, to determine how quickly your soil dries out and needs water again. More on soil probes below.
  • Once you know the rate that water percolates through your soil, you can precisely set the DURATION of the irrigation cycle in order to water to the full depth of the root zone.
  • This is important because trees are commonly over-watered. We assume trees need more water because the SURFACE soil looks dry. But many desert soils have a high water-holding capacity. Three to six inches below the dry surface, the soil profile is cooler and can often hold water for several days or weeks.
  • The point is to avoid putting water on top of water. This is not only wasteful; it also sets up conditions for various disease pathogens.
  • Using the soil probe, you can also determine watering FREQUENCY, that is the number of days between waterings. The goal is to apply water when the root zone completely dries out. A simple test to determine watering frequency is to watch your trees for signs of afternoon wilting. If the leaves of your tree or shrub begin to curl at the edges (wilt) after 10 days, set your watering cycle for 8 or 9 days.

Stay tuned for my series on Irrigation next month. In the meantime, for a closer look at watering and using a soil probe, visit our Integrity Tree Service Fact Sheets here.

 

Enhanced by Zemanta

Leave a Comment