Grevillea Robusta or Silky Oak has very vigorous tree roots

One of the many trees with a vigorous root system surrounding my garden.

Tree roots can annoy me. Especially in a suburban environment when you have some 30 metre gum trees, large mango trees and enormous Silky Oaks within 10 to 30 metres of your gardens and compost piles.

Every time you work with the soil you find pesky tree roots taking advantage of all the soil improvement being done. Not that you can blame the trees for taking advantage of the available nutrients, but it dampens my gardening enthusiasm.

I can’t tell you all the trees surrounding me, but I have highlighted the ones in red that I recognize.

The following table comes from the Australian Native Plants Society (Australia) 

Very vigorous tree roots

Botanical Name Common Name Botanical Name Common Name
Acer negundo * Box elder * Allocasuarina and
Casuarina species
She oaks, river oak, forest oak
Angophora species Large species Araucaria species Hoop, bunya and Norfolk pines
Black bean Corymbia species Large gum trees
Eucalyptus species Large gum trees Ficus species Figs
Grevillea robusta Silky oak Jacaranda mimosaefolia * Jacaranda *
Liquidamber * Lophostemon confertus Brush box
Broad-leaved paperbark Melaleuca styphelioides Prickly paperbark
Platanus acerifolia * Plane tree * Populus species * Poplars *
Quercus species * Oaks * Salix species * Willows *
Schinus molle * Pepper tree * Schefflera actinophylla Umbrella tree

* indicates an exotic species

Maintaining Enthusiasm

To maintain my enthusiasm I need to solve the problem of tree roots getting into my vegie beds. I’m not too worried about the compost piles as I use them after about 12 months and don’t get as much tree root growth in them.

I have been doing a bit of research and so far the best solution I can find are Wicking Beds. There are Rolls Royce ones and there are really simple ones.

The simplest wicking bed I have seen

One way to exclude tree roots

This is one solution to tree roots

Shopping bags you get from the supermarkets and a kid’s swimming pool. You fill the shopping bag with a good soil compost mix and plant your seedlings. Place the bags into the wading pool and add a couple of inches of water. The water travels up through the bag to the plants and doesn’t over water. Place an outlet in the pool a couple of inches from the bottom to release excess water when it rains.

Keep the bags separated and they will air prune the roots so that the bags don’t get joined together by roots migrating to the bag next door. The youtube link

Rolls Royce Wicking Bed

To get an idea of the Rolls Royce of wicking beds go here

The author must be a retired engineer or some similar type. He builds his EcoBeds, to a very high standard. I reckon that will they not only outlast him, but his grandkids as well. But you will probably agree, they are brilliant.

I like growing in the ground. I like learning about the quality of the soil and microbial life and doing everything I can to improve the soil and the microbial life in that soil. But short of digging a moat around my yard, I am finding it difficult to compete with those pesky tree roots.

When the yard has dried from the effects of Cyclone Marcia I will be starting on a wicking bed. The bed will be simpler than the Rolls Royce model, but hopefully effective at excluding tree roots.