posted 7 years ago
Redhawk beat me to it....mature eucalypts are the bane of many a gardener. On my section, even the pasture composition changes and becomes far less diverse in the corner of the paddock under the big eucalypts. The trees are super efficient at pulling water from the soil, which is an adaptation to droughts common in Australian climates, and the leaf and bark litter is loaded with aromatic oils including phenols, which are toxic to many species. Best of all, they burn like petrol bombs, even when green. In some eucalyptus forests, almost nothing grows in the understory, including seedling trees, until a bush fire clears everything out.
We can observe the bare ground in the photo in proximity to the big tree. That is the problem you'll have to creatively work around...treat it as an opportunity.