Gum tree underplanting is tricky – there are a lot of plants that really object to being under them. Certain plants will not thrive at all in that kind of environment.
Why are gum trees such an issue?
There are several things going on that impact the type of plants you can place under a gum tree.
- Shade – this is the most obvious thing you need to take into account. Look at how much shade your gum tree places over the ground underneath. If you do this at all times of the day, so you get a good idea of how much of the area is likely to be in full shade, partial shade or full sun. You will need to think about appropriate plants for the shade level.
- Soil Acidity – Because the acidity under a gum tree is proportionally very high, and usually out of the ”normal” Ph range, you will need plants that can handle that kind of soil.
- Allelopathic oils – The oils from the gum leaves (phenols), are what’s called “allelopathic”. This means that they can inhibit germination, growth, survival and reproduction of other plants. Obviously, you will need to find plants that can cope with this, otherwise you might be continually cleaning up your gum leaves (this is NOT a good plan if you want to actually have a life, by the way! ).
- Water – gum trees will be searching for water, and using available water. It’s best if you look for hardy, waterwise and possibly shallow rooted plants. Make sure you keep water up to the plants when they initially go into the ground.
Actually, there are a lot of different plants you can put under a gum tree, of all different types and sizes. You will probably be surprised by some of the suggestions, as they are quite common, hardy and colourful.
Specifically I’m talking about Australia here, and in particular, Adelaide in South Australia. Therefore, if you’re elsewhere, you may have to do some extra research to make sure that these plants will grow in your area.
Here’s a bit of a list for you!
- Geraniums – native and others
- Agapanthus
- Wild iris (dietes species)
- Native flax (dianellas)
- Paper flowers (Thomasia petalocalyx)
- Everlasting daisies
- Boobiallas
- Grevilleas
- Pale fanflower
- Running postman
- Goodenias
- Tom thumb
- Hebes also known as Veronica
- Swan River Daisy (brachysomes)
- Leopard plant (ligularia)
- Purple coral pea (hardenbergia)
- Coral bells (heucheras)
- Sweet peas (polygala)
- Basket grass (lomandras)
- Petunias
- Diosma
- Fescue grass
- native iris (patersonia occidentalis)
- Guinea flower (Hibbertias)
- Marguerite daisy
- Proteas
- Cone bush (leucadendron)