Acer rubrum 'RT4' MORGAN (INDIAN SUMMER) scarlet maple

MORGAN is a beautifully coloured variety of scarlet maple, which was discovered in 2002 by Ray Tate from the Angel Creek Nursery in Bishop, Georgia, USA. It was a single mutation among a number of October Glory seedlings planted at a nearby nursery in Morgan County. Among the 58 existing varieties of scarlet maple, MORGAN is the only one that has reddish-brown bark of younger branches and leaf petioles, which makes it unique because the bark of other varieties is always grey. He described his discovery in US plant patent No. PP16652 granted in 2006.

In all other respects MORGAN maple is very similar to the species and can be utilized the same way. It bears large, 5-12 wide and 5-10 cm long, deep green leaves with reddish-brown petioles. They usually have 3 petals, sometimes 5, and in autumn they turn bright red to deep orange for a relatively long period. Being a male plant, it does not set flowers or fruits, so there is no risk of producing invasive seedlings. Young twigs are bright reddish-brown, and with age the bark changes to light grey.

It grows fast and in good conditions (in evenly moist and fertile soil) it can grow up to a meter per year. It forms dense shrubs and trees with well-branched canopies without pruning. They are narrowly pyramidal when young, change to broadly oval with age, and maintain upright habit without overlapping branches. You can prune it and shape the tree in any way you like, preferably in autumn after the leaves have fallen or during frost-free period of winter to reduce sap bleeding. It is an ideal tree for medium-sized and large gardens, parks, and urban greenery, cheering them up with spectacular and vivid colours in autumn, ideally in combination with other autumn-coloured trees, for example acer saccharinum and ginkgo biloba with yellow leaves or red-leaved fagus varieties which turn amber orange.

Scarlet maple will grow in almost any soil, it also withstands wet feet. However, if you are looking for a strong and healthy tree with superb autumn colours grow it in acid soil (add peat) that is evenly moist throughout the year (mulch it well with bark), in full sun. It is wind and air-pollution tolerant. Stake young and freshly transplanted trees to a support for the first 3 years to make sure they get well established and have straight trunks. Fully hardy to -40°C (USDA zone 3).

Last update 25-10-2023