Morus acidosa Mulle - Mullberry

Morus acidosa 'Mulle' is a compact and fruitful selection of a Korean mulberry also known as Morus australis. It is highly cold-resistant. This small tree is particularly suitable for cold regions where it abundantly and regularly bears fruit from July to September. Appreciated for its edible, tasty, and sweet fruits, which resemble large elongated blackberries, it also offers ornamental foliage. Its beautiful light green leaves turn golden yellow in autumn before falling. Its modest stature and good tolerance to pruning make it a perfect candidate for small spaces. Adopt this mulberry tree in your garden or in a large container, but preferably place it a little away from the patio as its fruits can stain!

'Mulle' was selected in Sweden. Like all its counterparts (there are about 15 species of Morus), it belongs to the Moraceae family and produces latex in its tissues. Its ancestor's origins are found in East and Southeast Asia, particularly in Korea. 'Mulle' has the advantage of having a compact growth rate and a more upright habit than the typical species.

This small tree has a short and thick trunk, supporting a fairly narrow and tall crown. Its branches, inclined at 30 degrees, branch out quite low. Its growth is quite fast during the first few years, then slows down significantly. It can reach 4m (13ft) in height and 2.5m (8ft) in spread (compared to 12m (39ft) in height for the typical species). Its bark is a dull grey-green to reddish-brown; on older subjects it takes on a dark brown-orange hue. The bark of young branches is villous. The leaves are polymorphous, meaning their appearance and size can differ depending on their position on the branches and the age of the branch. They measure 6 to 8cm (2 to 3in) in diameter, 10 to 20cm (4 to 8in) in length, and are alternate, petiolate, either entire and cordiform, or divided into 3 to 7 more or less deep lobes and have a roughly toothed margin. The lamina is rough and fairly light green on the upper side, pubescent on the underside. It turns golden yellow in autumn before falling. 'Mulle' develops insignificant male or female flowers in different locations on the same plant in April-May. The harvest period is quite long. From July to September, the female flowers produce fleshy ovoid fruits, 3cm (1in) long, which are mostly almost black when ripe (sometimes red). The fruit is edible and juicy, with an acidulous flavour comparable to that of black mulberry fruits (Morus nigra). They are highly coveted by birds. The root system of this small tree does not appreciate transplantations: choose its location carefully!

'Mulle' is very hardy and not very space-consuming. It marks the garden with its unique personality and delights both young and old gourmets, while being truly undemanding in terms of the soil it is planted in, as long as it is properly drained. Uncultivated lands will benefit from its presence, as its leaves gradually enrich the soil every autumn. It can be welcomed in a small garden, for example in a small fruit hedge, alongside Japanese quince 'Cido', medlars, golden fig, Amelanchier ovalis, hazelnut trees, and cornus, for the great joy of children and birds. The fruits can be consumed fresh, in jellies, jams, or syrups.