Researchers have found that a tree can lose as much as 90% of its root system when it is harvested from the nursery. This is a vulnerable time in the life of a tree. It takes about one year per inch of trunk diameter for a tree to get established and grow roots in proportion to the size of its trunk and branches. That translates to about 1-3 years for the size of trees we plant. Here are some simple guidelines to aid establishment and insure success.

Watering Your Tree

Until a newly transplanted tree or shrub has extended its roots into the surrounding soil, the root ball needs to be kept consistently moist. Even “drought-tolerant” species need to be watered frequently at this stage. Since most root growth occurs in summer, be sure soil moisture is adequate when the weather is warm.

How often should a tree get water?

You cannot make up for lack of watering frequency by applying a large volume of water once a tree is stressed. Many factors affect the rate that the soil and roots will dry out. Of these, weather and soil type are probably the most important.

On well-drained loamy soil, watering 2 times per week is a good rule of thumb for new transplants.

Bump up to 3 times per week if:

• Weather is hot, dry, windy

• Soil type is sandy or gravelly

• Tree is planted on a slope or in a very exposed area

 Back off to 1 time per week if:

• Weather is cool, cloudy, rainy (if we get a lot of rain over a week, you can skip the watering)

• Soil type is heavy clay

• Tree is planted in a low spot, or area protected from sun and wind

Rainfall counts! A steady rain that totals ½ - 1 inch is perfect. However, we often only get 1/10” or less. Other times, an impressive downpour mostly runs off and does not penetrate the soil.

How much water does a tree need?

Plan to water about 2 gallons per inch of trunk diameter. If possible, allow the water to trickle in, versus dumping a bucket all at once. You want the water to soak the entire root system, not just get the top wet. Make sure the water is not running off to a low spot away from the planting area as well. Soaker hoses or Gator bags are great options, sprinklers not so much.

Other Considerations

Mulch Helps Retain Moisture

The best mulch is a layer of organic matter like wood chips (request free on our homepage). Keep the mulch pulled back from the trunk (no volcanos!). About 3” deep is recommended. Stone or plastics don’t add anything to the soil, and can create problems for the tree. Barriers such as landscape fabric are also not recommended.

Staking Can Help Vulnerable Trees

Your tree should not need staking and will grow stronger without it, but if it starts to lean send us an email and we can have a look. We stake a few trees per year that are planted in really windy spots. We’ll use a staking method that won’t damage the trunk, unlike this poor tree (see image).

Protect Young Trees from Rabbits and Deer

Rabbits like to chew on young tree trunks in the winter when they don’t have more tender plants available. Hardware cloth wrapped around the trunk from the ground to 2 feet up is a good idea. Make sure to check that the protection is not so tight that it could end up girdling the tree. 

If you have a cedar, white pine, or hemlock, the tree may benefit from deer protection if you live in a part of the city or county with lots of deer.

Fertilizer

Your tree will not need fertilizer the first year. The tree does not have enough of a root system to absorb the fertilizer and the resulting build-up of salts in the root zone can actually pull water out of the roots. Adding some quality compost as a top dressing and maintaining a layer of mulch as described above is the best way to improve the soil to encourage good root growth.

Those are the basics for caring for your tree. In reality, if you are watering your trees, you are doing great. If you have questions please let us know. Thanks again for planting trees!