MYRTLE BONSAI

The Myrtle Bonsai: The Aromatic Essence of the Mediterranean

Myrtle (Myrtus communis) is the soul of the Mediterranean maquis, especially of Sardinia. It is an extraordinary bonsai tree not only for its aesthetics, but for its sensory experience: one only has to brush the foliage to be enveloped in an intense balsamic scent. With its bark flaking off to reveal cinnamon-colored wood, rich white stamens flowers and dark berries, it offers interest in all seasons. It is a generous plant, but requires attention to water quality and climate.

Origin & species: Which Myrtle to choose?

Native to the Mediterranean basin, the Myrtle is an evergreen shrub. In bonsai, it is crucial to distinguish between varieties, as not all respond in the same way:
Myrtus Communis (type species): Has larger leaves and long internodes. Less suitable for small bonsai (Shohin), better for larger sizes.
Variety 'Tarentina': It is the queen of bonsai trees. It has tiny leaves, short internodes and naturally compact growth. It blooms profusely and produces white or black berries.
Varieties "Microphylla" or "Pumila": Often commercial synonyms of Tarentina or similar dwarf-growing cultivars. These are best for achieving dense, proportionate branching in a short time.

Exposure and Microclimate

Myrtle loves full sun. Bright light is the secret to achieving abundant flowering and maintaining compact vegetation (especially in Tarentina).
However, potted roots fear excessive heat. In midsummer, in the hottest areas, shading the pot or moving the plant into half-shade in the afternoon will help prevent dry strikes.

Watering

Unlike other Mediterranean trees such as Olive, Myrtle cannot tolerate prolonged drought in pots. If the potting soil dries out too much, the plant quickly collapses.
Water regularly as soon as the soil surface dries. In summer you may need water every day. Beware of waterlogging, however: fine roots will rot if left to soak.

Water quality

Myrtle is a plant that tends to be calcifuge (hates lime).
Continued use of hard tap water leads to ferric chlorosis (yellow leaves). Use rainwater, or allow tap water to decant. Periodically administer Iron Chelate to green up the foliage.

Substrate

Prefers a slightly acidic or neutral, fresh and draining soil.

  • Recommended mix: 40 percent Akadama, 40 percent Kanuma (or acidic blond peat) and 20 percent Pumice.
  • The addition of Kanuma or acidic substrate helps prevent lime scale-related problems and improves nutrient uptake.

Repotting

This is done in spring (March-April), every 2-3 years.
Myrtle has a dense, capillary root system. When repotting, comb the roots gently and never cut them back drastically (maximum 30%). If you cut too much, the plant may stunt or dry out branches.

Fertilizing

Fertilize from spring to fall with organic fertilizer.
To encourage flowers, use a fertilizer with more Phosphorus and Potassium before summer. Using specific fertilizers for acidophilic plants is a good strategy to maintain dark green foliage.

Flowering and fruiting

Flowers appear in late spring/summer: they are white, fragrant and have long stamens.
They are followed by berries (black or white depending on variety) that ripen in autumn/winter. They are edible and very decorative, but they consume energy: on forming plants best removed.

Structure pruning

Heavy pruning is done in late winter. Myrtle wood is very hard and brittle.
The plant tends to withdraw sap if the cut is not clean and sharp. Always use sharp tools and immediately cover with healing mastic.

Maintenance pruning

During the growing season, the plant (especially Tarentina) grows creating compact "cushions." You need to regularly thin the inside of the foliage to let light and air through, otherwise the inner twigs will dry out and mealybugs will nest.

Stapling

This is done on the new green shoots. As soon as they elongate beyond the desired outline, shear them off with scissors or your fingers, leaving 2 pairs of leaves. This stimulates the plant to start again from the backward buds, thickening the vegetation.

Binding & folding

Caution Old Myrtle branches are stiff as glass and break without warning.
Tying should be done only on young, green branches. The bark of mature branches naturally flakes off (this is an aesthetic feature, not a disease), so the wire could ruin this process or etch the very tender underlying bark.

Diseases and pests

  • Mealybug: The number one enemy. It hides inside the dense vegetation of the Tarentina variety. Check the interior often.
  • Aphids: On the flower buds.
  • Ferric chlorosis: Leaves fading due to lime water.

Winter & protections

Not an alpine plant. In the South, it lives outside year-round. In the North and Central, it should be sheltered in a cold greenhouse if temperatures drop below freezing. It fears intense frosts that can burn the fine branches.

Annual calendar

  • January-February: Rest, cleaning dry branches.
  • March: Repotting (with acidic soil).
  • April-May: Fertilizing, mealybug prevention.
  • June-July: Flowering, frequent watering.
  • August: Half-shade during hot hours.
  • September-October: Berries, fall fertilizer.
  • November-December: Protection from frost.

Useful products for this bonsai

Frequently Asked Questions about Myrtle

Which variety is best to start with?
Without a doubt the Tarentina (or Microphylla) variety. Having naturally tiny leaves and very short internodes, it already looks like a "finished" bonsai even when young, making it much easier to set up than the common Broadleaf Myrtle.

Why are the leaves turning yellow but the veins remain green?
This is a clear symptom of ferric chlorosis. You are using too much lime water or the soil has lost acidity. Use Iron Chelate right away and, if you can, start watering with rain or demineralized water.

The bark is peeling off in strips, is it diseased?
No, indeed! It is a valuable characteristic of mature Myrtle. Old bark exfoliates revealing a smooth cream or cinnamon-colored wood underneath. Do not forcibly peel it off, let it fall off naturally.