Northeastern Area Association of State Foresters

Improve tree planting survival by using a gravel bed

Friday, September 15, 2017
Many communities plant bareroot trees in the spring because that’s what is available, they’re cheap and easy to handle. The drawback to planting bareroot trees in spring is their poor survival rate. The culprit is the lack of fibrous roots to take up water and nutrients and the need to water during dry periods in the summer.


Roots of a bareroot tree before going into a gravel bed.

Fall is a better time to plant bareroot trees because while the roots continue to grow, the crown of a tree will stop growing when air temperatures are cooler than soil temperatures. The drawback to fall planting is balled and burlap trees are usually the only stock available from nurseries, and are expensive and hard to handle. So what is a city to do? Construct a gravel bed!

Roots of a bareroot tree after going into a gravel bed, showing the fibrous root system produced.

A gravel bed is an irrigated pile of gravel where bareroot trees are heeled in and held from the spring until the fall.  During this time the above ground portion of the tree grows normally while a fibrous root system forms in the gravel. Trees are easy to remove from the gravel bed and transport to planting sites.
 
Hendricks, MN (population 694) showcases their Tree Gravel Bed

Over 60 Minnesota communities and counties are using gravel beds.  Pictured here is the largest, operated by Hennepin County (Minneapolis and western suburbs) with a 1,500 tree capacity, and one of the smallest in the City of Hendricks, in rural Minnesota, population 694.  Hendricks decided to showcase their gravel bed, by locating it in their busiest park.
Benefits of gravel beds:
 
  • Tree health and survival rate improved by:
    • Increasing fibrous roots, which minimizes transplant shock.
    • Planting in fall instead of the spring.
  • Money saved by using barefoot trees that are typically half the price of containerized trees and a quarter the price of balled and burlap trees.
  • Tree species availability increased because generally there are more species available as bareroot trees compared to containerized and balled and burlap trees.
  • Injuries by staff and volunteers decreased because bareroot trees are lightweight and usually need shallow holes.


The All You Need to Know About Community Gravel Beds by the University of Minnesota is a great resource to use to learn more about gravel beds and to get started on developing one. Download a copy today! tinyurl.com/ydxbnw9n .

 

For more information, please contact:
Jennifer Teegarden
Community Forestry Program Coordinator
(651)259-5269