When planting new trees for clients I explain the importance of proper watering. I just came across this explanation on the website of one of my local nurseries and it does a great job of explaining proper watering.
Importance of Watering
The most important aspect of caring for your new tree is a good understanding and proper
timing on watering. Trees have transpiration rates similar to our sweating. The hotter and
windier it is, the higher the transpiration rate. During our hot summer months, when the
transpiration rate is extremely high, 3-4 waterings per week may be necessary. During the
dormant season the transpiration rate is very low and may only require a few waterings per
month. Sometimes it seems easier to water when in doubt. This can cause a problem, however,
if too much water over an extended period of time is applied to your tree. Too much water
can result in displacement of air space in the soil with water, and over time the trees can suffer
or die from lack of oxygen in the soil. This all makes it sound difficult to know when to water,
but it really is not. Just remember to drench when watering, saturating the entire root zone
and then let oxygen return to the soil (let the roots dry) before watering again. Remember, it is
better to water when needed rather than water by a calendar.
Here is a general watering schedule:
• In Spring when daytime highs are comfortable and hopefully rains are frequent:
• 1-2 waterings per week.
• In Summer when temps are over 90 degrees: 3-4 waterings per week may be necessary
• In Fall/ Winter during the dormant season: 2-3 waterings per month may be sufficient. Keep
in mind though that if rains are few and temps are higher than normal, 1-2 extra waterings
may be necessary
If you have a newly planted tree:
• It is best to water every day for the first week and every other day for the next 1-2
weeks then follow the general watering schedule.
• A general rule for the amount of water your tree needs is dependent on the size of the
container your tree was in. For example, if you bought a 20 gallon tree, your tree will need 20
gallons of water daily for the first week. If you fill up a 1 gallon container with water pressure
at a slow stream, multiply the amount of time it took by the container size of your tree (ex.
20 gal.) and that is about how long you should be watering each time for the first 3 weeks.
• Also note that a sprinkler system IS NOT adequate for your first year of watering for a newly
planted tree. A water hose or soaker hose is fine.
link to the original is here