I have several large pine trees and eucalyptus trees on the hill behind my house. The leaves and needles find there way into my rose garden and flower beds. Will this prevent them from growing well, and is there anything I can do about it?
Pine Needles and Eucalyptus Damaging Soil
Certified GKH Gardening Expert
Both pine needles and eucalyptus leaves in themselves will not hurt your plants, but both needles and leaves are known to raise the acid levels in the soil they decompose in. This will not cause a problem for your plants as long as you regularly test the soil (which should be done anyway to make sure nutrients are balanced) and treat the soil if the acid levels get too high.
Here is information on treating high acid in soil: