Growing a mimosa tree

How to Propagate a Mimosa Tree

The mimosa tree is an evergreen shrub that’s native to Brazil. It has fern-like leaves that droop or close up when touched and reopen a few minutes later, earning it the name “Sensitive Plant.” The mimosa tree can grow up to about five feet in height with a three-foot spread. It has fluffy pink flowers that are ball-shaped and prickly, bristly seed pods that can cling to animal fur and clothing. Propagating mimosa trees is usually done by seed, but it can also be done by cuttings.

Harvest the seeds in late summer or early fall, when the flowers begin to wilt. Carefully remove the bristly seed pods from the flowers. Dry and store the seeds until early spring.

Place the seeds in a dish and cover them with hot water. Allow them to soak overnight, until they swell. Select the swollen seeds for sowing and re-soak the ones that didn’t swell.

Fill a two-inch planter pot with equal parts sand and peat moss. Plant three seeds in the pot, inserting the seeds down into the potting mix about two or three times the seeds’ thickness.

Maintain a temperature of at least 55 degrees Fahrenheit. Place the pot in bright indirect sunlight and water the seeds just enough to keep the potting mix moistened. The seedlings should begin to germinate within three or four days.

Select the strongest seedling after the three seedlings have grown to about four inches tall. Transfer the strongest seedling to a six-inch planter pot.

Propagating from Cuttings

Take cuttings in the spring or early summer to propagate your mimosa tree. Cut at an angle a two-inch-long side shoot with a piece of old wood attached (a “heel”). Remove the lower leaves from the cutting, allowing two upper leaves to remain.

Insert the severed end of the cutting into a two-inch planter pot filled with moistened peat moss. Place the pot in a plastic bag and tie it at the top.

Place the plastic-covered pot in bright indirect sunlight and keep the peat moist. Maintain a temperature of about 75 degrees Fahrenheit.

When the roots begin to develop and new growth emerges, remove the plastic bag and transfer the cutting to a six-inch pot filled with one part peat moss and one-part sand.

This method of propagation works particularly well for the mimosa tree.

It is especially useful if you wish to replace a tree that was damaged and you still have access to its remains.

Here are the tips on how to reproduce a mimosa tree from bark.

  • Read also: how to care for mimosa trees

A special type of cells, cambium

A tree grows thick thanks to the work of a surprisingly thin layer of cells. Just under the bark, a thin line of cells marks the difference between the bark and wood of the trunk.

This is called cambium. It’s virtually invisible to the human eye because it’s extremely thin.

However, since it’s loaded with nutrients and connected to the sap vessels that channel food and water up and down the tree, it takes on a shiny sheen when bark is freshly peeled from the trunk.

Suckers of salvation

Mimosa often sprouts suckers from various spots along its bark. Usually, these are removed to ensure the tree grows nicely. In this case, this particular trait of growing is what makes this solution work.

All you have to do is to recover those portions of the damaged tree, cutting them away from the trunk.

  • Use a chisel or a sharp knife to slice the bark about 6 inches (12 cm) wide horizontally, about 6 inches (12 cm) below the sprouting sucker.
  • Pull the bark up along the tree delicately, tearing the bark along the edges.
  • Instead of tearing, you can mark the edges with the knife or chisel.
  • Pull up until the sprout is set free, and then go on for another 6 inches (12 cm).
  • Slice the end of the strip cleanly.

You should end up with a rectangle of mimosa bark that is about twice as long as it is tall, with the sprouting sprigs in the center.

Pot and protect

Place this slab of bark with the mimosa tree sprig facing up in a pot filled with a blend of garden soil and soil mix.

Ensure it drains well, for example check that the pot has a hole at the bottom.

Place the pot in a spot that gets permanent shade but is still quite luminous. Water whenever the soil is dry at the surface.

The sprouted bark will start working on producing roots and you’ll have a new mimosa tree up and growing in just a few weeks!

  • Note: this method will endanger the life of a mimosa tree that is alive and well. Prefer cuttings in that case if you wish to propagate your tree. If you wish to try this method nonetheless, reduce the size of the swath of bark to a rectangle 3 inches wide by 4 inches tall at most (8 cm by 10 cm). That way you’ll maximize chances of your source mimosa to survive.

Learn more about cambium

Cambium is a film of cells that is only one or two cells thick. It lines the entire trunk of the tree between the bark and the wood.

It can be found in the trunk, branches and even the roots.

These cells are special in that they are undifferentiated: this means they can potentially turn into different parts of the plant.

Many living beings start out as undifferentiated cells, even we as human embryos. Some of our cells even retain the capacity to morph into whatever tissue may be needed up through adulthood.

When these cambium cells from the mimosa bark slab are set in contact with the soil, they answer the needs of the growing shoots above it. They start growing into roots that will ultimately feed and nourish the plant.

Smart tip about bark cuttings

When these have developed enough, the shoots will resume growth and this is a signal that the bark cutting can be transplanted.

Read also:

  • How to care for a mimosa tree
  • A common method for propagating plants, cuttings

Credits for images shared to Nature & Garden (all edits by Gaspard Lorthiois):
Mimosa from bark by Pauline under © CC BY-ND 2.0
Mimosa grown from bark in pot by Pauline under © CC BY-ND 2.0
Branch of mimosa flowers by Alain Aubry under license

Moving Mimosa Trees: How To Transplant Mimosa Trees In The Landscape

Sometimes a certain plant just doesn’t grow right where it’s locate and needs to be moved. Other times, a plant may quickly outgrow a landscape. Either way, moving a plant from one site to another can cause stress, or even death, if not done properly. Fast growing mimosa trees can quickly outgrow an area. While the average 25-foot height of one mimosa tree doesn’t sound that hard to fit in to the landscape, mimosa trees seed profusely, and one mimosa tree can quickly turn in to a stand of mimosa trees. Continue reading to learn about properly moving mimosa trees and when to transplant a mimosa tree.

Mimosa Tree Transplanting

Many times, mimosa trees are planted as specimen plants in landscape beds near a home or patio. Their sweet smelling flowers bloom in midsummer and then form into long seed pods that disperse seeds everywhere. As we get busy with other things in the garden in late summer and fall, it’s easy to overlook the seeding habits of mimosa until the following year when seedlings pop up all over.

With its adaptation to almost any soil type, tolerance of full sun to part shade and quick growth rate, your one specimen mimosa can quickly turn into a thicket of mimosa. While this may be fine for a windbreak or privacy screen, a dense stand of mimosa can take over a small landscape bed. In time, you may find yourself needing to move mimosa trees to a location where they can be allowed to grow and seed densely.

When to Transplant a Mimosa Tree

Timing is important when transplanting a mimosa tree. Like any tree, mimosa trees are easier to transplant the younger they are. A small sapling will have a much greater survival rate if moved than an older more established tree. Sometimes, it is necessary to move a bigger tree, though. Either way, safely transplanting a mimosa tree will take a little prep work.

Established trees should be transplanted in late fall to early winter after all leaves have fallen off and gone dormant. Small saplings can be dug up in spring and potted to give away to friends or family, or until a proper site is selected.

How to Transplant Mimosa Trees

First, select the new site for the mimosa. This area should have well-draining soil and be full sun to part shade. Pre-dig the hole in which the mimosa will be going. The hole should be twice as wide as the root ball you will be placing in it, but no deeper than the tree is presently growing. Planting any tree too deeply can cause root girdling and improper root development.

Oftentimes, arborists will recommend digging a hole slightly deeper than the plants root ball, but then creating a small mound of soil in the center for the root ball to sit upon so that the tree itself is not planted any deeper than it should be, but the horizontal roots are encouraged to spread out and down into the deeper area of the hole.

Once your site and planting hole are prepared, place a wheelbarrow filled halfway with water and a transplanting fertilizer, like Root & Grow, next to the mimosa tree you are digging up. Depending on the size of the tree you are moving, with a clean, sharp spade, start digging about a foot to two out from the base of the tree.

An older, larger tree will have a larger root system and will need more of these roots intact to survive the move. A clean, sharp spade will help easy cut through these roots while not damaging them too badly and reduce transplant shock. Established mimosa trees can have long, thick taproots, so it may be necessary to dig down around the tree up to 2 feet to get a good portion of this taproot.

After digging up the mimosa tree, place it in the so you can easily move the tree to its new location in the landscape. Place the mimosa tree in the prepared, new hole. Be sure that it will not be planted any deeper than it previously was going. Add soil under the root ball, if necessary, to raise it. Fill the area around the roots with soil, gently tamping it down to prevent air pockets. Once the hole is refilled with soil, dump any leftover water and rooting hormone in the wheelbarrow onto the root zone.

It will be necessary to water your newly transplanted mimosa tree daily for the first week. Do not use any fertilizer until spring. After the first week, you can water the tree twice a week for the next two weeks. Then drop down to a good, deep watering once per week. When watering any newly planted tree, you should give it about a twenty minute, slow trickle of water for deep watering. Once a mimosa tree is established, they can tolerate drought and will require very little watering.

Plant Pick: Silk Tree or Mimosa Tree

Latin name: Albizia julibrissin

by Vancouver Island Master Gardeners Association

How very fortunate that we have this tree at Milner Gardens.

It’s very exotic looking in summer with its ferny leaves and its pink fluffy flower heads starting in June. It can tolerate drought and some winds. It’s very fast growing (60cm) a year. Ferny leaves are slow to leaf out in spring and are about 25cm long

eventually leading up to gorgeous pink fluffy fragrant flower heads which develop in groups at the ends of the branches in early summer and bloom June to August. Literally dripping with nectar they attract bees, butterflies and hummingbirds.

Seed pods follow the flowers and persist into winter. They resemble flat bean pods approximately (12.7cm) long and yard clean up is recommended for the seedlings.

The bark is smooth and grey.

Pruning is best done in late winter or early spring.

In the northwest this tree is susceptible to Nectria canker, (Nectria cinnabarina) which leads to limb die back. The presence of brilliant pink to coral fruiting bodies on the surface of dead limbs are signs of the disease. Once it has got to this stage you must prune out the dead limbs.

Photo credit: Chinese Medicine Center(L), Milner Gardens (R)

Form:

May be a large bush or a small tree. Mature trees grow into a v-shaped form

Foliage:

bi-pinnate ferny leaves

Height/Width:

4.572m high, 9.144 m high

Hardiness Zone:

Exposure:

Full Sun

Flower colour:

Pink

Leaf colour:

green

Flower time:

July/August

Preferred soil

& watering:

Well drained moisture retentive soil but adaptable

Other:

Flowers and bark are used in traditional Chinese medicine

How to Transplant a Mimosa Tree

Mimosa Tree with blooms image by Photoeyes from Fotolia.com

Mimosa trees or silk trees (Albizia julibrissin) grow readily in hardiness zones 6b to 9, spreading their seeds widely. Gardeners who plant one tree may soon have several due to its aggressive propagation. Transplant mimosa trees if they don’t have enough room to grow, if they’re not planted in full sun or simply to site them in another part of your yard. In temperate areas, transplant the tree in either spring or fall. Gardeners in the northern end of the mimosa tree’s range should transplant only in spring so the tree is acclimated to its new environment before winter.

Water the mimosa tree until the soil becomes saturated for two days prior to planting. This loosens the roots, making it easier to dig up the tree.

Select a new location for the mimosa tree that provides full sun and enough room for the tree to mature. When fully grown, mimosa trees average 15 to 25 feet in height and 25 to 35 feet in width.

Dig a hole at the new spot that’s twice as large as the plant’s root ball. If you’re transplanting a container tree, you can estimate this easily. If you’re transplanting a ground tree, use the Garden Line’s estimate of 9 to 12 inches of root ball per inch of tree trunk diameter.

Remove rocks, weeds and roots from the hole. Jab your shovel at the bottom of the hole to roughen the dirt, which will help your mimosa tree adapt to its new environment.

Dig your mimosa tree out of the ground. Begin at a distance twice the size of the root ball and dig into the ground with your shovel. Work closer to the tree and down; as you edge close to the root ball you will see roots, which can guide your digging. Keep digging until you’ve unearthed the whole root ball. If you’re moving a container tree, skip this step.

Tug up on the trunk of the mimosa tree to free it from the ground. It should come readily, but if a couple of roots cling to the ground, cut them with clippers.

Carry the tree to its new location, or place it in your wheelbarrow and wheel it. Set the tree in the new hole so it sits at the same depth as it was planted before. Ensure the tree is vertically straight.

Backfill the hole with soil to transplant the tree. Firm the soil around the tree’s roots and trunk gently.

Water the mimosa tree to settle the soil and remove air bubbles. Add water until the soil grows saturated.

Transplanting Mimosa Tree – Knowledgebase Question

Unfortunately, in my experience this tree is very difficult to transplant because it has a very sparse root system and the soil falls away from it as soon as you try to dig the plant up. If you are determined to try it, simply trace along the root as best you can and take as long/large a piece as possible. Keep the root moist (you might wrap it in damp but not soaking wet newspaper and place that in a plastic bag left loosely open) and keep the plant itself cool but above freezing so that it stays dormant while in transport. Replant immediately, water in and and mulch well. You will probably need to stake the plant as well. Over the coming season keep the plant watered (the rule of thumb is an inch of water a week from you or the sky) while it becomes established. I would expect the soil to be frozen in midwinter so this may be very difficult to do. Instead, you might harvest some seedpods and take them with you to plant at your new location. I think this might be the best course because it is unlikely that your tree will be winterhardy in that area unless you can provide it with a very sheltered location out of the wind and in a warm microclimate. A temperature of 5 degreesF for any period of time can damage the tree, and a young or stressed tree is most susceptible to such damage. All the best if you decide to try it!

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