How to Water Newly Planted Fruit Trees to Maturity

Q. When I spoke to the master gardener volunteers last year about watering peaches (I had a Stark bare root from Gurney's that only made it until August) I received a wide range of answers including 35 gallons per week. Any recommended rule of thumb for watering these?

A. There are two things we have to consider when watering; how much and when. A third thing to consider is where and should be considered as the tree gets older. The how often part doesnt change as the trees get bigger. The "how much" does since "big trees use more water than little trees." The  "where" to put the water is important. As tree roots have to spread wider to anchor the tree against wind and carrying its fruit load and get enough water to support its size we have to encourage growth away from the trunk as well.

How Much. Regarding watering, give them the same amount of water as the container you would find them growing in, in the nursery. If it is equivalent to five gallon container, give them 5 gallons, 15 gallon container then 15 gallons. Even though these containers are not actually five or fifteen gallon capacity it still gives you about the right idea. Of course you can give them more than that but that would be the minimum and gauged according to size, increasing yearly until their mature size. Fully mature trees might require 30 to 40 gallons each time you water. If  possible, try to change the number, size and spacing of emitters instead of the number of minutes on the irrigation clock.

 

Example: Newly Planted 5 gal Fruit Trees (Number of Minutes Kept the Same)

 1st to 2nd Year - 4 to 6 gallons (ex. 2 each 3gph emitters, one on each side)

2nd to 3rd Year - 8 to 10 gallons (ex. 3 each 3gph emitters, triangular spacing)

3rd to 5th Year - 10 to 15 gallons (ex. 4 each 3 gph emitters, square spacing)

4t Year and Up - Replace emitters with more gph and/or more emitters

Where. Wet to an area equal to the canopy when young. As it matures the wetted pattern should be at least half the area under the canopy if possible. In commercial orchards of smaller trees like peaches and almonds under drip irrigation this "wetted area" is genearly considered in two stages.

The first stage is when they are young and a drip line is laid near the trunks with two emitters; one on each side of the trunk about 18 inches from it. The second stage as the tree approaches production, in the third and fourth years, a second drip line can be added on the opposite side of the trunk and the two lines places about 18 inches from the trunk on either side. Two more emitters are added to this new line so that the emitters are in a "square" pattern surrounding the trunk. This wets a larger area under the area under the canopy.

When. You should never have to water daily even in the hottest time of the year. The most frequent in our hot dry desert climate will most likely be every three days in peak summer water use. If you do, you run the risk of root rot or collar (lower trunk) rot. The dormant winter frequency may be 10 days to 2 weeks apart if you have mulch. Water to a depth of 18 - 24 inches each time you water.

When to Water
February 1 - April 30   Water once a week
May 1    Water twice a week (or sooner, depends on weather)
June, July, August Water three times a week if excessively hot, sandy soils and no surface mulch
September 1    Water twice a week
October 15   Water once a week
December 15 (leaf drop) Water every ten days to two weeks through the winter