Tree Care Info
How much and how often should I water my new tree here in Ojai?
The answer depends on several things:
It depends on soil type and weather conditions; how much moisture is already in the soil; and what kind of tree it is. In order to get this right, one must observe. It's easy enough to look at the leaves and trunk, but it is also necessary to probe into the soil to see what's going on there. The surface may look dry, but a few inches down it could be moist - this is common when it is sunny after a rainy period. But the opposite could be true, especially if you water frequently but don't let the water soak in deeply: the top layer is moist but it is bone dry down below.
Each time you water the tree it should be a slow deep soak at the edges of the tree's dripline (not directly on the trunk), with water penetrating to the deeper tree roots - 12" deep for a young tree. For most new 15 gallon size trees, this will be about 10 to 15 gallons of water. Then wait and let the surface layer (top 6") dry out between waterings. If you do this you will be able to water less often and the tree's roots will go deeper, which is a good thing.
A soil probe is the best tool to quickly check subsurface moisture. It also has the added benefit of letting some air into the soil. Yes, air - it's one of the ingredients plant roots need in order to live. Also, if you think it best to err on the side of too much, keep this in mind: Most residential plant problems are caused by overwatering.
Keeping all that in mind, we suggest you water your tree once a week in summer; every 10 to 14 days in spring and fall. Keep track of the weather. More frequent waterings may be necessary in very hot weather. In cool, moist weather or heavy soils that hold water (like clay) water less frequently.
If your tree is in a lawn area, it may not get enough from lawn watering depending on watering schedule. Short frequent waterings will keep a lawn green but do not water the deeper tree roots. Water your tree deeply – and less frequently than a lawn. Keep a thick layer of mulch over the roots of the tree, but don't cover up the base of the trunk (also called the root crown). With thick mulch you can water less often. And keep lawn and weeds away from the tree trunk! - at least a 2 foot radius circle around the trunk. They compete with the tree's roots.
Watering trees during drought conditions
Although mature native oaks generally don't need summer watering, many other species can use some help.
General Tree Care Links
Watering mature trees
Watering young trees