The main Cornwall Park Kauri Grove was planted in the 1920's. It comprises approximately 150 kauri along with 50 rimu and 50 tōtara.
The trees were planted in lines 5 metres apart. The kauri range in height from 24-27 metres tall with stem diameters up to 80 cm. Rimu and tōtara have similar heights and trunk diameters. As of 2021 the tallest tree in the grove is a 28 metre rimu.
Other species including , northern rātā, NZ cedar and karaka have been planted around the grove in recent years.
Due to kauri dieback disease the kauri are now fenced off. A lot of regeneration of native broad leaf species is now evident in this part of the grove. There are several smaller groves planted in Cornwall Park planted from 1930-1940. The groves attract a variety of native birds including shining cuckoo, morepork, fantail, kererū and tūī (Barker, K. P., 2021).