Earlscliffe's pride is its fantastic collection of Southern Hemisphere plants. Tender plants, which usually are to found in South America, South Africa, Asia and Australasia, thrive in this Irish garden. Indeed, in just under 2.5 hectares, one can find Cyathea and Dicksonia tree ferns, Protea, Banksia, banana, Schefflera and Juania among others. Some Chilean, Canary Island and New Zealand plants, such as Luma apiculata, Echium pininana and Cordyline australis are so much at home that they have acquired weed status. The array to be found is even more impressive when one considers that no artificial protection from the elements is provided during cold and wet weather.

The owners point to Earlscliffe's position by the sea on a South-facing slope for this abundance of sub-tropical plants. This, and the sheltering presence of the Hill of Howth to the North, provides the garden with a unique microclimate. It also ensures spectacular views for the visitor, southwards to Dublin Bay and eastwards towards Baily Lighthouse.