Last week we mentioned how to properly inspect and monitor the soil of and around a newly planted tree. This monitoring is important to ensure the root-ball receives the correct amount of moisture. What about a big established tree, however? Are they fine just with what falls in the form of rain? Great question to ask and again it depends on some factors such as location, species and if the tree is an evergreen or broadleaf. To start, lets acknowledge that all trees need water to survive. Some however are more suited to withstanding extended dry periods. Generally speaking, evergreens tend to be more drought tolerant. Think of our native Pine and Fir trees. They often must survive our hot dry summers with little to no water from precipitation. They can do this because their needles are very efficient at using water. Adversely, many broadleaf trees such as River Birch and Cottonwood are not as efficient. This process of pulling up water through its roots, trunk, branches and then its evaporation from off the leaves and needles is called transpiration. So, to put it more plainly, many conifers have a much slower transpiration rate than broadleaf trees making them more efficient with their use of water. That said, I still water the conifers in my yard during the summer. While they may be more tolerant of dry times, I do not want them unduly stressed. This can lead to them being susceptible to attack by insects. Bark Beetles are a real concern here in the west and trees become very susceptible during extended dry and drought periods. We often think of trees in the forest but even conifers here in town can be vulnerable without sufficient water. Especially on construction sites where the organic layers have been stripped and compaction is and issue. More next week on how and when to best irrigate your established trees and ways to make your watering efforts last longer. As always, for further questions, quotes and consultations, give us a call today!
