Glorious, Great and Grounded: A Tree Blog

Small Tree, Big Problem: Removing Invasive Dwarf Umbrella Trees From Your Land

It's no secret that Australia suffers from extensive problems with invasive species, and these unwelcome plant and animal invaders can wreak havoc on the country's unique and isolated ecosystem if left unchecked. One example, the dwarf umbrella tree (Schefflera arboricola), a small and unassuming shrub, but even a single tree can quickly grow into a damaging and dangerous infestation.

Why should I remove dwarf umbrella trees from my land?

Dwarf umbrella trees have a number of properties that, while beneficial to the tree itself, can make them a tenacious and hardy pest plant:

  • Exotic species: The dwarf umbrella tree actually hails from the islands of the South China Sea and has escaped cultivated gardens in Australia to grow as a wild weed. Because of its exotic nature, it can effectively out-compete native species that have had no chance to adapt to its presence.
  • Parasitic growth: While dwarf umbrella trees are capable of growing free-standing, they are also voracious climbing plants, and the flexible trunk and stems will wrap around almost any tall tree or structure nearby. Using this climbing ability dwarf umbrella trees can reach substantial heights, while potentially causing structural damage to buildings and sapping badly needed resources from host trees.
  • Strong roots: This hardy tree is capable of growing in a variety of poor and dry soils, largely thanks to its strong and extensive root system. Indeed, these roots are so strong that they are capable of penetrating subterranean pipes and basements, causing leaks and extensive property damage.
  • Exclusive growth: As its name would suggest, dwarf umbrella trees have large, shady leaf clusters that can block out large amounts of sunlight. They also have a tendency to grow together in dense thickets; these two traits combined make for a highly competitive plant that can effectively starve out competing native species, crops and ornamental plants by depriving them of light, nutrients and moisture. 
  • Regrowth potential: Dwarf umbrella trees are also capable of remarkable regeneration, and a tree cut down to ground level is still capable of regrowing quickly if left unattended. If a tree is uprooted, any root fragments left behind can form 'suckers', small shoots which can eventually grow into new trees. This makes the tree particularly difficult to control using traditional means.

How do I have dwarf umbrella trees removed from my land?

Despite this tree's remarkable hardiness, there are still effective ways to rid your land of even the densest dwarf umbrella infestation:

  • Uprooting: Small, isolated shrubs and trees can generally be effectively removed by simply uprooting them, although you should take care to remove every possible trace of root growth to prevent suckers from forming (these suckers have limited resources and will generally not grow back if plucked quickly). Thickets of trees can be tackled with mechanical controls such as chain-pulling and bulldozing.
  • Repeated felling: If a dwarf umbrella tree is growing in an area with pipes and other delicate underground structures that make uprooting impractical, repeatedly felling the tree will eventually starve it of nutrients and cause it to die. However, this is a slow process that may take months or even years to have conclusive results.
  • Controlled burns: Thickets of dwarf umbrella trees found in relatively isolated positions such as fields and waterways can be burned out. However, you should make sure that a controlled burn is legal under local land laws, and hiring a tree removal service to plan and oversee the burn is highly recommended to avoid any nasty accidents.
  • Herbicides: Commercially available herbicides containing glyphosate are effective dwarf umbrella killers, but take great care when using them. Spillages can quickly contaminate groundwater and nearby waterways, potentially landing you in costly legal trouble. Apply the herbicide to the stumps of freshly felled trees for the most effective results, and have professional tree removers administer the chemicals if you are at all unsure about using them.