Watering Newly Planted Trees

Watering and Plant Survival

Improper watering is the number one reason that NEW trees do not survive the first year.  Improper watering could be considered overwatering, underwatering or inconsistent watering. Proper watering during the first year is the key to the establishment of new plantings.  For trees planted in spring, the first real test is getting through the hot summer months. For trees planted in fall, the main concern is getting through their first winter (especially for evergreen trees). Planting stress (shock) for a new tree is directly related to the size of the tree.  Larger trees will take a longer time to establish a healthy rooting system and recovery from initial planting shock.

Simple math from The BIG Oak = A newly planted tree will have one year of planting stress for every inch of trunk diameter (1 inch tree = 1 year of stress)

How Much Water?

Many factors impact how much watering will be required to help a new tree establish.  These factors include tree type, temperature, humidity, wind, soil type, and soil conditions.   Soils should be kept consistently moist but not saturated.  Trees in sandy soils will require much more watering than trees in heavy clay soils.  Overwatering (specifically in clay soils) can be just as damaging as underwatering. 

For this newly planted maple (below), the entire root zone beneath the mulch should be kept consistently moist (but not saturated) to help the tree establish.

Summer Watering Patterns (for Minnesota)

Newly planted trees should be watered 3 x / week for the first 4 weeks and then as follows:

• Deciduous trees: 2x / week, 5-7 gallons each time for 1-2” diameter trees (more for larger trees)

• Evergreen trees: 2x / week, 5-10 gallons each time for 6-foot trees (more for larger trees)

• Watering visits may need to be increased during periods of excessive heat or in sandy soils.

Fall Watering Patterns (for Minnesota)

Newly planted trees should be watered at least 3 times for the first 2 weeks and then ONCE per week at the amounts listed above.   Depending on soil conditions, additional watering for evergreen trees in fall is often a good idea.

A GOOD SOAKING RAIN CAN BE COUNTED AS THE EQUIVALENT FOR ONE WATERING.

Watering tip from The BIG Oak = Newly planted evergreen trees should be watered well into fall for as long as possible (mid-November would be optimum) to ensure they get through their first winter.

Sprinkler Systems

In general, sprinkler systems are set up for frequent, shallow watering best suited for turf.  Automatic sprinkler systems are sufficient for watering lawns but are not geared for newly planted trees.  Trees will get some benefit from irrigation systems, but often need supplemental watering to become established and get through their first year.  Unless a newly planted tree is growing in heavy clay, I would not even consider irrigation systems as a watering source. Once a good rooting system is established, the reliance of additional watering can be reduced.