When planting trees in Phoenix choose the tree wisely. Don’t plant Palo Verde trees. They are beautiful, have bright green trunks, and are native to Arizona. However, most people overwater them and/or don’t deep water them. This can result in a shallow root system and a top-heavy tree. The tiny leaves collect the water dragging the tree down or breaking branches. The trees will split or fall over in a storm.
Mesquite trees are generally more durable and are also native to the Arizona desert. But just like Palo Verde trees, if mesquites are overwatered, or not deep watered, they too will be top heavy and fall over in a storm. Another negative for mesquite trees is they drop a ton of seedpods in the summer. Due to their aerodynamic shape, the pods are almost impossible to remove with a blower and we all know the landscaper’s motto – “If it don’t blow, it don’t go.” Some companies can spray to reduce the pods but there will still be plenty to pick up. If the seedpods are left they will sprout as they are trying to make more trees. Traditionally mesquite trees have huge thorns but nurseries have developed a thornless mesquite. They still have some thorns but they are a lot smaller. I am waiting for a mesquite with no pods but that probably is not going to happen.
What trees are the best to plant in Phoenix? Desert Willows tend to do well, but again these are desert trees so don’t overwater them. An Ash tree referred to as an evergreen or Shamel Ash is another good choice. After the first year, it needs very little water. It is a fast-growing shade tree that can grow up to 40 feet tall and wide in just 20 years. Moon Valley Nursery has developed a version of the evergreen ash for the Phoenix area.
Other trees to avoid are: Palm trees are not native to Arizona and drop stuff year-round. This makes a big mess especially if you have a pool. They need annual trimming but don’t trim until the stalks bloom. The stalks start growing and blooming in May. The trees should be trimmed early in June. If you trim too soon, the stalks will grow back and you will have to spend the money to trim again. That’s a very expensive lesson. If you don’t trim the palm trees the stalks and husks will come off during storms.
Sissoo trees are a terrible choice. These trees grow fast and large but most people underestimate how big they will get. This results in cracked walls and sidewalks. And they sprout new trees from their roots resulting in constant maintenance.
Silk Oak and African Sumac are two more bad choices. Silk Oak trees drop leaves all year long. In the spring and summer, the female African Sumac drops blooms and fruit that make a mess. The male African Sumac is a better choice but is also constantly dropping leaves. These trees also spread to neighboring areas. Once established the only way to get rid of them is to remove them by the root.
Don’t plant too many citrus trees. One citrus tree can feed many houses when the fruit is ripe. If you don’t remove the fruit it can attract roof rats. (I will write more about roof rats and other pests in a future newsletter.) All fruit trees and other trees need to be watered at least once a month in the winter and once a week during the summer. Deep water entails 8 hours of watering at a slow pace. A drip system will not keep your trees alive or provide good fruit. This is very important for newly planted trees. If you don’t deep water the tree roots will stay at the top of the ground referred to as root float. This means the trees may fall over during a monsoon storm and they will die if they are not constantly watered.
Certain Pine trees have been developed for use in the Phoenix area. However, pine trees drop needles all year round and create what is called pine straw. If this straw is not removed regularly it can become a haven for insects as well as a fire hazard. If planted near your pool your new job will be constantly removing the pine needles every day, especially after a windstorm. The final benefit to pools is the sap from the needles will clog the pool filter.
Some trees like mulberry and fruit-bearing olive trees are no longer sold in Phoenix. This is due to the high pollen count they create.
Allow for growth – Regardless of the tree, you plant do not plant it close to fences, house foundations, or sidewalks. The roots can cause costly damage.