Sumach
The two forms of this genus which we offer are both large suckering, clump forming, deciduous shrubs which originate in North America and are fully hardy. Rhus glabra, the scarlet sumach, and Rhus typina, the stag’s horn sumach, are grown for their attractive alternate pinnate leaves which turn a brilliant yellow or red in the autumn. Both have yellowish-green upright panicles of flowers at the tips of their new growth which are up to 10in long and appear in summer. On female plants the flowers are followed by dense clusters of spherical hairy crimson-red fruit.
R. glabra grows to around 8ft and the clump, which will develop from the outside of the original plant, can have a spread as great as its height given time. R. typina grows taller to 15ft or so with an eventual spread of up to 20ft. At Caerhays we are now growing Rhus verniciflua which is a single stemmed deciduous tree with glossy dark green leaves but rather undistinguished loose panicles of small yellow-green flowers. It does not perform here as yet on the autumn colour front either.
If you are concerned at containing your rhus in its place you can prune it back hard each year to around 1-2ft from ground level. This may reduce its flowering potential. Suckers can be dug up and removed or destroyed as necessary. If there are no concerns at the size and spread of your plant then the only pruning necessary is to remove any broken or crossing stems in early spring to improve the overall health and appearance of the plant.
Root cuttings or hardwood cuttings taken in the autumn can be set in a cold frame. This produces a quicker more mature plant than taking semi ripe cuttings taken in the summer. Seed should be collected in the autumn and sown in the cold frame. To ensure that you do get seeds you will usually not need a male and a female plant as R. glabra and R. typina are both typically dioecious. In a cottage garden context there will probably be other flowering rhus not far away anyway.
Some very fine examples of both rhus species grow along the main road from Burncoose towards Lanner on the way into Redruth.