by Bertrand Dumont
At a nursery producer, for a tree to be classified as such it must have a single trunk from the ground, over at least two meters free and branches above. It is also considered that it must be at least 5 meters high at maturity.
Yet during your visits to Passion jardins garden centers you have already seen types of mini-trees, with very small stems. Often no more than 1.25 to 1.50 m. These plants were really in the tree section, but if you trust what I’ve just told you, technically they are not trees. So, what are they called?
In horticulturists’ jargon, they are called stem shrubs or standards (horticultural term meaning “on stem” in English). These are actually plants that are natural shrubs, but can develop a strong stem. At the end of it, a shrub (the crown) can develop or horticulturists graft branches to form one. Sometimes the rootstock is a different but compatible plant.
Benefits, but also precautions
Leading (in the sense of directing) or grafting shrubs on stems allows both to obtain small plants and to offer plants with a different appearance. An advantage for you because you have access to more plants to express your creativity.
However, you should know that these plants are usually a little more fragile than a tree or shrub. It is the junction point between the “trunk” and the base of the stems that is more brittle than in conventional trees. So, planting the majority of shrubs on stems (especially grafted) has to be avoided in very windy places or where they receive a lot of snow in the winter (unless you protect branches from potential breakage).
Stars … without being big headed
Because of their appearance, stem shrubs are rather stars than supporting roles. You can use them to give height in a flowerbed or to mark a focal point in a small space.
In fact, your imagination, and because you have to put the right plant in the right place (to offer optimal living conditions, especially in terms of soil and humidity) are the limits of their uses.
Their uses are also guided by the effects that these plants bring to a garden. They are classified into four categories. They are used for:
- their flowers;
- the coloring of their foliage;
- the particular shape of their leaves;
- their weeping habit.
Here are some examples for each category.
Shrubs on stems, decorative because of their flowers
With their beautiful white flowering, Service berries are spectacular in the spring. They are followed by the double-flowering almond tree with pink flowers. Then the crab apple varieties hatch, whose crown is restricted. They all flower white. To close off spring, Korean dwarf lilacs with pink flowers, very fragrant and common lilacs, offered in multiple colors, are adorned with their thousand fires.
At the end of the summer appear the stem hydrangea flowers. These will persist much of the fall and even winter. Most of the time the flowering is white, but in many varieties, it is adorned with shades of pink and more or less dark red. Several stems are arched under the weight of the flowers. A unique show.
Shrubs on stems, decorative because of their purple-red foliage
It is mainly a variety of shrubs with red foliage. The red-leaved Japanese maples are sometimes proposed, grafted on stems more or less long. Be careful, they are rather fragile plants.
An Eastern redbud and a stem-borne ninebark also present burgundy leaves all summer long.
A purple European hazel with very dark purple leaves, and gnarled and tortuous branches, offers a striking sight.
Shrubs on stems, decorative because of their particular foliage
The Siberian peashrub has pale green leaves that look like ferns. These very loose stems give it a semi-weeping appearance. It flowers yellow in the spring.
The tortuous locust is decorative by its zigzagging and tortuous branches which carry a curly, dark green foliage.
In the spring, the spotted willow is covered with pink shoots that give rise to pinkish white leaves. It must be pruned every year to produce very colored shoots.
Shrubs on stems, decorative because of their weeping habit
The weeping peashrub is a classic. Its branches fall frankly along the trunk. In spring they are covered with yellow flowers.
Walker’s weeping peashrub is actually a hybrid between a weeping peashrub and a Siberian peashrub. Its drooping branches are covered with fern foliage.
Once grafted onto a stem, the dwarf Arctic willow takes on a half-weeping habit. With its small leaves and long stems, it gives a very airy look to the arrangements.
The weeping arctic willow is very decorative in the spring when it is covered with small silver catkins on beautifully weeping stems.
In order to choose the right stem shrub that best suits your landscaping, ask for advice from garden coaches from the Passion Jardins in your area.