PGMS Member Area > PGMS Knowledge Center

Planting Trees and Shrubs So They Survive & Thrive

Eric Vorodi
Regional Extension Agent
Ornamental Horticulture
Penn State Cooperative Extension

May-June, 2002

Eric Vorodi is a member of the Horticulture Department staff at Penn State University. In June 2001 he was honored by Penn State with the Vice President’s Award for Customer Service. Below he provides Forum readers a seven-step plan on planting trees and shrubs that will flourish.

1. WHAT YOU NEED TO KNOW BEFORE YOU DIG THE HOLE.

A. Is the site extremely wet or dry?
Can you and/or will you make major changes to affect water relations in the soil at this site such as changing the grade or adding organic matter? If not, has plant material been chosen that will tolerate site conditions?

B. What is the pH and nutrient status of the site?
Has a soil test been taken? If not, are you (the seller) or they (the buyer) willing to assume the risk of putting the wrong plant in this location. With soil test results, adjust the pH and fertility as required. Use lime to raise pH and either sulfur, iron sulfate, or aluminum sulfate to lower pH.

C. Where are the roots in the rootball?
Don’t assume anything. Examine and gently disturb the rootball if necessary to determine where the roots are and if you need to break up the rootball (container stock).

D. Where is the natural division between root and trunk (stem)?
Don’t assume the natural division between stem and roots is at the soil surface of your plant. Be suspicious of all plants – both B&B and container stock! Be aware that some container plants are not container-grown but actually containerized which means they were field-grown and then transferred into a container. The container is then topped off with media giving an artificial soil surface location. YOU MUST ALWAYS LOCATE THE UNION OF ROOT AND TRUNK BEFORE CONTINUING.

2. DIGGING THE HOLE.

A. B&B trees and shrubs.
For B&B trees and shrubs, dig the hole no deeper than the ball’s height, but 2-5 times the ball’s diameter. In poorly drained, compacted or heavy clay soil, dig even shallower. For shrubs, it is better to dig and amend one large planting bed than numerous individual holes.

B. Container grown trees and shrubs.
For material in containers you can’t dig the hole until you determine how tall the rootball will be when you are done manipulating it – it will always get shorter! Start with a hole 1/2 the depth of the container.

3. HANDLING PLANT MATERIAL.

A. Always handle plant material by the rootball or container - never the top.
Lifting a plant by the top hangs the weight of the rootball on the small feeder roots and tears them loose.

B. For B&B material, remove the string and pull back the burlap.
Gently use your fingers to move soil away from the base of the trunk until you find the root flare. Now measure the
height of the ball from the root flare to the base of the ball.

C. Pull container-grown plants out of their container and examine roots and root flare.
If roots are matted or circling the rootball, break up with a sharp garden tool. When finished, the rootball will have decreased in height.

D. Remove all tags, ties and strings from trunk and branches.

4. PLACEMENT OF THE PLANT.

A. Is it plumb?
To check if trees are standing straight, stand back 20-30 feet and examine. Move 90 degrees to either side and examine again. Adjust and repeat until tree is plumb.

B. Orient any angled growth or newly emerging leader into the prevailing wind.

5. BACK-FILLING THE HOLE.

A. Soil amendments.
Research indicates that most plants do best when native soil is returned to the hole un-amended or with only slight modification. In cases where the soil is extremely heavy (clay) or drains too well (shale or sand), up to 10% organic matter can be mixed with the backfill to increase air and water holding capacity. NEVER ADD SAND TO ANY SOIL TO INCREASE
DRAINAGE! IT DOES NOT WORK!

B. The backfill must be firmly tamped into the hole surrounding the rootball for several reasons.

1. Tamping removes air pockets, which allow roots to dry out.
2. Tamping brings backfill into firm contact with the rootball, so that water may move from the surrounding soil into the rootball in place so that staking is not necessary.
3. Tamping holds the rootball in place so that staking is not necessary.
4. Watering when the hole is half backfilled and again when finished will help settle the soil and remove air pockets.

C. Starter fertilizer high in soluble phosphorus may aid in establishing its place so staking is unnecessary.

D. Mulch.
Apply 3-4 feet of mulch over the soil surface and in as large of an area as feasible. Keep mulch away from the stem of the plant. DO NOT MOUND MULCH LIKE A VOLCANO. MULCH SHOULD ALWAYS LIE FLAT ON THE GROUND!!! Mounding mulch causes rain to run off of rather than onto the rootball. During establishment, it is imperative that plants have access to rain when it occurs.

E. Moisture wicking.
Be especially careful when planting container grown stock that you do not leave the rootball exposed to the air. Soilless media used in container production will wick moisture out of the ball and into the atmosphere like a sponge. The result is a rootball that can be completely desicted and the death of the plant. The top of the rootball of container stock must be covered with mulch.

6. STAKING

A. Staking is almost never necessary!
Staking increases cost and labor and is often done incorrectly.

B. Staking is only necessary when:

1. …planting in sandy or shaly ground.
2. …the rootball is small or broken.
3. …planting on a very windy site.
4. …planting bare root trees.

C. Staking is done for 2 reasons.

1. To immobilize the rootball and prevent damage to small roots from movement of the ball.
2. To prevent trees from blowing over in very windy situations or when the rootball is too small for the plant.

D. Staking affects the future growth habit of the tree.
Improper staking causes trees to grow tall and spindly and makes them unable to support top growth. Proper staking (when necessary) allows trees to sway in the breeze which increases trunk diameter. This process is known as “thigmomorphogenesis.” Thigmomorphogenesis means “change in form as a result of tactile stimulation.” Tree trunks swaying in the breeze grow thicker more rapidly than trunks of staked trees.

E. Staking is done in one of three ways:

1. Use three short ground stakes with ties angled up to the trunk and secured at the first branch unions.
2. Use 2-3 tall wooden stakes with horizontal ties placed at 1/3 the tree height.
3. Use one stake on the windward side with tie placed at 1/3 of the tree’s height.

In all cases, use ties made of soft material that will not injure tender bark. Loop the ties in such a fashion that they will not girdle the tree as it grows. It is preferable to use a material that will decompose in a year or two.

7. WATER
Water once a week for the first three months. Water monthly for the remainder of the first year. In case of drought, water weekly until rain resumes. Water individual trees and shrubs by laying a hose at the base of the plant and allowing water to trickle onto the rootzone for 30-60 minutes. To water entire beds of plants, use a soaker hose. In low maintenance situations, use tree gators to ensure that trees are watered during establishlisment.

Following this seven-step plan should allow your trees and shrubs to survive...and thrive.