Mimosa, superb winter flower tree

mimosa tree

Mimosa, in winter, bears  exceptional fragrant, bright gold yellow flowers.

Key facts about mimosa

Name – Acacia dealbata
Family – Mimosaceae
Type – tree

Height – 13 to 32 feet (4 to 10 meters)
Exposure – full sun
Soil – well drained and sandy

Foliage – evergreen     –     Flowering – deep winter to spring

Proper planting of the winter mimosa tree, its pruning and the care you’ll give it will help you have a magnificent mimosa tree, whether in pots or in the garden.

Planting a winter mimosa tree

Mimosa is planted preferably in spring or in fall in a sunny spot and, ideally, sheltered from wind.

If you choose to grow your mimosa tree in a pot for a deck, balcony or terrace, its fragrance will spread in the entire vicinity as soon as the first flowers unfurl.

Indeed, mimosa tree particularly loves sun-endowed emplacements that are protected from drafts, and especially well-drained soil.

  • You’ll do well in avoiding heavy clay soil.
  • For chalky soil, select a flowering mimosa tree that is grafted with a local native root stock. It will be better suited to that particular soil type.
  • Follow our tips on how to plant a mimosa tree.
  • Propagate your mimosa tree through cuttings in summer (highest success rate, but spring is also fine).
  • Gather seeds from a tree, they germinate readily.
  • You can even grow a new mimosa tree from bark.

In regions with harsh winters, your best option is to plant your mimosa tree in large pots so that you may bring them indoors over winter.

Growing mimosa in a pot

Mimosa flowers and branches in a pot.Mimosa is a shrub that will grow very well in a pot or large garden box, even though proper growing conditions must be provided.

  • It’s a pleasure to place this pot near a window you open in winter to ventilate. The fragrance will spread throughout your home!
  • Detailed run-through on how to grow mimosa in a pot.

Note that you can have the best of both worlds: a full-blown tree outside, and a vase with cut sprigs in the house! Indeed, mimosa buds will still bloom as cut flowers.

Mimosa tree and winter freezing

Mimosa tree sporting flower buds in the middle of icy rain and snowstorm.Mimosa tree resists freezing if moderate, 23°F (-5°C) at the coldest. This is especially true when the bouts of freezing are short.

When growing directly in the ground and if the weather freezes deeply in your area, protect your tree by implementing our advice on protecting plants against the cold.

  • Remember: wind worsens cold. Shelter your tree from wind.

Switching from pot to ground

If you transfer a potted mimosa to the ground, remember to winterize it for at least three years.

This is especially important if you’ve previously been bringing it indoors for protection.

These first three “outdoor winters” will gradually harden the tree until it can cope against freezing on its own.

Pruning and caring for mimosa

Caring for mimosaOnce properly settled in with a developed root system, the mimosa tree calls for minimal care. The only thing you might fear is having a late deep frost spell hit the mimosa tree in full bloom.

Otherwise, mimosa is so vigorous that some people call it an invasive plant. But stand assured: regular care and pruning will restrain its rapid growth.

How to trim a mimosa tree

Your mimosa tree will happily stay small if you prune it often, and if you let it grow it can turn into a tall tree.

Pruning takes place after the blooming, in spring, because if you cut the tree in winter, you won’t have a single flower.

  • Cut branches that have born flowers back lightly.
  • As soon as they appear on the trunk, pinch suckers off. These usually appear at ground level, and they’ll weaken the rest of the tree.

If, at the end of winter, you notice branches that are broken and blackened because of freezing, feel free to cut them off because they, too, would weaken the tree.

How fast does a mimosa tree grow?

A single shoot can grow up to 5 feet (1.5 meters) in a single season!

  • From this shoot, in the next season, side branches fan out.

If you want a low, bushy shrub:

  • snip every branch as soon as it reaches two feet (50 cm).
  • They will branch out and create a round, dense shrub that will be covered in flowers in winter.
  • Don’t worry about the timing, this can be done any time.
  • Also, feel free to cut back drastically if you need to reduce the size of the tree. Mimosa can cope with hard pruning quite well.

If you want a tall, tree-like shape:

  • Let the topmost, leading stem grow freely.
  • Cut out suckers that grow from the side of the trunk.
  • Remove suckers up to the height you want your “trunk” to look like.
  • Above this, branches will start fanning out and grow, forming a tree-like crown.

Mimosa will start back from the roots even if freezing killed the trunk off. Nurture the new sucker depending on how you wish to shape your tree.

Note: Always prune your tree just after a split or y-junction with a smaller branch. An alternative is to prune just after (above) a bud that can take the lead and grow. Otherwise you’ll end up hatracking your tree, which isn’t a good thing.

Watering a mimosa tree

Mimosa isn’t a tree that requires much watering, except when potted, of course. However, it hates excess moisture that has a tendency to make the roots rot, eventually killing the tree.

Watering a mimosa tree planted in the ground

  • You must water in case of prolonged dry spells, but otherwise stocks of water contained in the tree itself should answer the mimosa tree’s needs.

Watering potted mimosa

  • Mimosa trees grown in pots require regular watering that is moderate in quantity during winter.  Only provide it when it isn’t freezing.
  • In summer and in case of hot weather, water in the evening to avoid having water evaporate immediately.

Mimosa tree, key points to know

Tall mimosa tree in full bloom.Mimosa is known thanks to florists who sell it in January, when flowers are still in the bud. It already is fragrant enough to spread its scent throughout an entire house!

Its foliage is evergreen and its blooming has a fresh, appealing smell.

A winter-blooming tree, it is also particularly appreciated for the color of its flowers, the fragrance they impart and, most of all, its blooming period.

Winter’s deepest and darkest months is when this tree drapes itself in full color and releases its delicious spring-like fragrance throughout the neighborhood.

You can also take advantage of all this tree’s gifts on your terrace, balcony or deck if you plant it in a large garden box. Simply water it as soon as the soil turns dry.

Note that there is a certain confusion in terms: the tree that is commonly called Mimosa tree is actually an Acacia, whereas the tree that is commonly called acacia is really the locust tree. In addition, for Americans, a mimosa is a tree of the Albizia genus, the silk tree.

Now, about varieties: over 1200 mimosa varieties have been numbered throughout the world, and the first ones were introduced in Europe first along the Mediterranean, then along the Atlantic. They’ve spread across the temperate hemisphere ever since.

Smart tip about the mimosa tree

No need to add any fertilizer because a mimosa tree never needs fertilizer, even upon planting. An exception to this is when growing mimosa in pots: the soil must be replenished. Simple mulch is enough and will keep water from evaporating and weeds from growing.

Image credits (edits Gaspard Lorthiois):
CC BY 2.0: Nacho
CC BY-NC 2.0: nofrills