Plants Under Courtyard Olive Tree

Question

Hello, your help would be much appreciated because we have run out of ideas! I live in Melbourne, Australia (which has a Mediterranean climate) in a large apartment block with an open internal courtyard. See photo. We have 3 large planter boxes with healthy olive trees growing in them. The courtyard gets sunshine throughout the middle of the day for several hours. However we would like to grow some ground cover under the olives to cover the mulch. We have tried geraniums and herbs (thyme, parsley, etc) but they haven’t survived either because it’s too dry or too little direct sunshine or the soil type is wrong, – or something else! (the olives are watered from the base via water reservoirs around the perimeter of the plastic planter box). Do you have any suggestions?

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Answer 1

The best thing you can do for the olive trees is leave mulch only. Any groundcover will just compete for nutrients and water. Digging around in the soil also can disturb the roots of the olive trees.

If you still want a groundcover, choose one that is perennial, rated for light shade (since it's under the tree canopy) and carefully try to plant without disturbing the trees' shallow root system. Here are some ideas:

https://www.gardeningknowhow.com/ornamental/trees/tgen/planting-garden-beneath-trees.htm