The Persian Silk Tree (Albizia julibrissin) grows natural in open forests and hilly areas from Iran to China, but it was introduced from Iran, which is why it is called the Persian Silk Tree. The other common name, Mimosa, is confusing, since there is another group of plants, mostly with yellow flowers, called Mimosa trees. The natural tree is more upright, but trees in gardens are usually ‘V’-shaped or even umbrella-shaped as they mature, usually becoming wider than they are tall.

The foliage is divided and ferny in appearance, with leaves up to 20 inches long. The leaves have the unusual habit of folding at night and ‘going to sleep’. The leaves of wild trees are green, but in the Summer Chocolate Mimosa Silk Tree they are a beautiful deep burgundy in spring and early summer, becoming chocolate brown later in the season. This makes the tree attractive even when not in flower. Summer Chocolate was developed by a controlled breeding program in Japan and selected by Masato Yokoi from thousands of seedlings in 1990. After testing and trial growing in selected gardens it was introduced into the USA and patented in 2003.

Growing Summer Chocolate Mimosa Silk Trees

As an exciting specimen tree in a lawn, or planted in a bed with other flowering trees and shrubs, the Chocolate Mimosa Silk Tree is sure to attract attention and interest from everyone who sees it. It also makes an attractive plant for a large container, adding height and interest to patios and terraces. It grows best in warmer areas, from zone 6 to 9; flowering best where the summers are hot and the fall is dry. In cooler, damper regions it can be grown on a sunny wall, as described in our Growing Trees and Shrubs on Walls article, so even if you are in zone 5 you can enjoy this tree if you have a dry, sunny spot to plant it in.

A Persian Silk Tree in flower is an eye-catching treat, since the flowers are unique in their form. They look like large tufts of silky threads, white at the base and then pink in color. The Chocolate Mimosa Silk Tree has larger flowers in a richer, deeper pink color. The flowers spread along the branches and occur all summer long, like exotic powder-puffs. They are also deliciously fragrant. After flowering seed pods like beans may develop and persist into winter, adding to the interest of this tree.

Sun and Soil

When it comes to soil the Chocolate Mimosa Silk Tree is an easy plant to satisfy. It will grow happily in all types of soil from sand to clay and from acid to alkaline soils. It does best in a warm, sunny spot that is dry in summer, but some water should be given for the best growth and maximum flowering.

Planting and Initial Care

To plant your Chocolate Mimosa Silk Tree, allow plenty of room around the tree for its spreading habit. Allow at least 10 feet in each direction for the spread of your tree. Dig some rich organic material into the soil to give your plants a good start and then dig a hole three times the width of the pot but the same depth as the pot. Place your new arrival in the hole and replace most of the soil. Flood the hole with water and when that has all drained away, replace the rest of the soil and put a mulch two or three inches deep over the root zone. Water your plants deeply each week for the first season and after that watering is only needed during longer dry spells.

Remove any weak or dead branches and trim back the tips of the stems in late winter to encourage strong new growth. Container plants can be stored for the winter in a cool shed or garage to protect them from severe cold and then brought out in spring. Grown this way you can enjoy the Chocolate Mimosa Silk Tree almost anywhere in the country.

Buying Summer Chocolate Mimosa Silk Trees

Our growers produce our plants from selected specimens that are true to name, with good flower color and strongly-colored foliage. They use a special method of taking pieces of the roots from these top-grade plants, rather than growing them cheaply from seed, which gives variable and often inferior results. This rare variety is protected by plant patent and can only be grown by licensed growers. Avoid cheap seed-grown plants that will definitely not have the special foliage color and excitement of this wonderful plant.

Our Chocolate Mimosa Silk Tree plants are guaranteed to be the correct, patented variety and will perform beautifully in your garden. However supplies of this rare plant are often limited, so take advantage of their current availability and order now. Your tree will be shipped to you the following day.

The Mimosa Silk Tree grows quickly into a small tree with a broad, spreading crown like an open umbrella. With its widespread branches it is ideal as a quick-growing shade tree for a lawn or patio, where in just a few years it will give a circle of shade big enough for outdoor dining. In time it will exceed 20 feet in height and spread, sometimes reaching 50 feet, but typically staying quite a bit smaller. It can be grown either as a tree with a single trunk, or as a multi-stem tree. You can make this choice once it is established, and then prune it to give you the look you want. As a multi-stem tree it grows into a broad vase-shape, and it is wonderful for background planting, in semi-natural areas, and for planting in sunny, dry places. It is also a good choice for a tree in a large pot, where it will quickly produce a lovely mature look.

The bark of the stems is smooth and greenish-gray when young, turning darker gray-brown and developing long vertical stripes of lighter brown in older wood. The foliage is extraordinary beautiful and interesting. Each leaf is 10 to 20 inches long, and 5 to 10 inches wide, with a green central stem carrying 4 to 6 shorter stems along each side. Those stems in turn carries 20 to 30 leaflets, ¼ inch long, along each side, giving the leaf a ferny, very divided look. Remarkably, the leaflets can move, and every night this plant ‘goes to sleep’, with the leaflets folding up and hanging down. No wonder Persians call it shabkhosb which means ‘night sleeper’, and the Japanese call it nemunoki, the ‘sleeping tree’. The leaflets will also fold during rain, and when the leaves are shaken, so when you receive your tree it will probably be sleeping inside the box. The leaves are a rich mid-green, and they give the Mimosa Silk Tree a beautiful airy look.

The Mimosa Silk Tree is in bloom for weeks and weeks, from June or July onwards, looking wonderful and very exotic. Along the branches, at the end of each growing tip, clusters of many strange flowers appear. The petals are very small, and hardly visible. Instead it is the stamens – the pollen-bearing parts of the flower – that are long and showy. There are hundreds of them, each one bright pink, with a tiny yellow tip of pollen. The look is like the crest of an exotic bird, and a tree in bloom is glorious. The blooms give out an exotic sweet fragrance, and bees, butterflies and hummingbirds all love to visit them. When the flowers finally end, they are replaced by 7-inch seed pods, looking like flattened bean pods, which turn from green to brown and last well into the winter, long after the leaves have fallen.

The Mimosa Silk Tree grows best in areas with hot summers, and it is tolerant of both humidity and dry heat.  It is very drought resistant once established, although for rapid growth regular deep watering is recommended if it is planted in a very dry location. Any well-drained soil will suit it, from sand to clay and from very alkaline to acidic. This easy tree grows almost anywhere. It has no pests, and deer leave it alone. Avoid wet areas, as this can lead to a disease called wilt, so always plant in a drier part of your garden. It is hardy in zone 6, and really thrives in zones 8 and 9. In areas with cooler summers the tips of the new branches may not ripen fully before winter comes, so some trimming may be needed in spring to remove dead tips, especially on younger trees that are growing very vigorously.

The Mimosa Silk Tree is also called the Persian Silk Tree or the Nemu Tree. It is not a ‘mimosa’, which is an Acacia tree, and it is called by botanists Albizia julibrissin. It is a unique species in the large Pea family, growing wild in Iran, and westward all the way to Japan, although it now grows naturally in many countries. It was introduced into Europe long ago, in 1749, by the Italian naturalist Filippo degli Albizzia, who it is named after. This tree is always in high demand, from gardeners who like their trees fast-growing and exotic. Order now, while we still have stock available – we will usually ship it to you the very next day.