Now that fall has arrived and nighttime temperatures are cooling, it's a great time to plant trees and shrubs in the Phoenix area The moderate fall weather gives tree roots an opportunity to grow and establish in the ground before any chance of winter frost, and without scalding daytime temperatures. Simply put, fall planting gives your trees a better shot at growth and good health.
Here are some tips to remember when planting trees to make sure they thrive in the desert sun:
Select the Best Tree For Your Area
Who doesn’t want fall color in their landscape? But which trees can you plant to give you that color? The key is to choose the trees and shrubs that will thrive in our area while needing less maintenance.
For example, you might love the gorgeous fall colors of a Bigtooth Maple (Acer grandidentatum) but, while it’s native the Arizona, it doesn’t do well in the warmer temperatures of the Phoenix area. Ask your local nursery how to get some fall color with a more suitable tree, and check recommendations against homeowner association rules and tree care needs. The more drought and heat tolerant, the better!
Consider Location, Location, Location
A tree might be able to handle heat and drought, but if it grows too rapidly, too slowly or too large for the area you want to place it, then it’s not a good choice. It's easy to learn information such as mature height and width of a tree from the product tags or nursery staff – or from your friendly local arborist.
Here are some location-related questions to consider:
- Will the tree shade your house in summer?
- Are there power lines near where the mature canopy will rise?
- Will branches rub on your home's roof after a few years?
- Will the roots grow under your driveway, sidewalk or walls?
- Can you easily water the tree?
Prepare the Planting Hole
You can't do much to fix soil problems at planting time, but you can prepare the soil to help the roots grow. That means digging a hole about three to five times wider than the diameter of the root ball and loosening the soil around the edges.
Measure the root ball from where the roots bulge at the base of the tree (you may have to pull soil away from the trunk to find the root flare) down to the bottom and dig your hole only that deep. Leave the soil at the bottom of the hole undisturbed.
When planted, you want the tree roots to be below ground, but the trunk flare (where the trunk turns into roots) to sit slightly above ground.
Lift the tree carefully, making sure you or a helper are supporting the root ball (instead of grabbing and carrying the tree by the trunk only).
Once the tree is placed in the hole, backfill with the soil you removed and water well. It often helps if you build a small “wall” of soil around the hole to prevent water from flowing away from the root zone.
All newly planted trees, even those labeled drought tolerant, need plenty of water for the first year or two until their roots have established in the ground. In most cases, slow dripping water at ground level (not from an overhead sprinkler) is best for all desert plants, including young trees.
If you see water standing for a long time after soaking a tree, your soil probably doesn't drain well, which means you can water less often, but slowly. If water drains quickly, or you know the soil is sandy, water more often. The key is to get the water down to where the roots area, rather than just wetting the soil surface.
With these tips in mind, you can help ensure your newly planted trees grow well in your landscape and stay healthy, improving curb appeal and the value of your property.