The plant’s dark green leaves are small, lanceolate, and leathery. Little white, fuzzy, bowl-shaped flowers come in late summer. The myrtle needs a long warm summer to produce blooms, which are followed in autumn by edible fleshy fruit that resemble the size and purplish-black color of blueberries. Each fruit produces up to 30 seeds. The cinnamon-colored bark peels and becomes furrowed with age, as the trunk thickens slowly. While it naturally has a bushy habit, the common myrtle can be trained as a low-mounding spreading shrub, an upright small tall tree, or a tiny bonsai. Depending on the variety and the conditions, this long-lived perennial tree can grow up to 16 feet tall within 10 to 20 years.
Light
Give the plant full to partial sun in a west or south-facing location sheltered from the cold, drying wind. If growing as a bonsai indoors, it will need a lot of light and air. Set in semi-shade outside in the hot summer. In autumn, bring inside a cool room where temperatures are around 50 degrees Fahrenheit. Place on a south-facing windowsill or beneath grow lights.
Soil
Establish Myrtus communis in moist but well-drained soil. It will adapt to clay or sand, though, for best results, plant under glass in loam-based compost in filtered light with good ventilation. Beware of iron chlorosis in highly alkaline soil that has a pH higher than 8.3. If this occurs, lower the soil pH with a treatment of elemental sulfur or nitrogen fertilizer.
Water
Water the root ball regularly (once a week or more) when the plant is young, but do not soak as this could also contribute to possible iron chlorosis. An older plant prefers a deeper watering every two to four weeks but can do well without water for shorter periods, as well. Myrtle does not do well with high concentrations of lime found in tap water. It may benefit the plant to harvest rainwater for waterings.
Temperature and Humidity
Hardy in USDA Zones 8-11, the common myrtle is frost tender and hardy to 10 degrees Fahrenheit. It does not tolerate high humidity.
Fertilizer
Outdoors, fertilize once a year in early spring. Indoors, use a liquid fertilizer weekly during the growing season. Watch the plant in the winter because if it’s growing even a little bit, you may need to fertilize it every two weeks.
Common Myrtle Uses
As discovered by the ancient Romans and Greeks, the flowers and fruit are edible. Fruit can be eaten fresh when ripe, made into a drink, or dried to be used as an aromatic food flavoring in savory Middle Eastern dishes. Flavor sauces and syrups with dried myrtle fruits and flower buds. Flowers have both a sweet scent and a sweet flavor. In Italy, some people eat the flower buds directly off the plant or use them to garnish their salads. An essential oil can be made from the leaves and twigs. This plant has been known to have antibiotic, antidiarrhoeal, antiseptic, and astringent properties.
Common Myrtle Varieties
‘Tarentina’ is also known as Tarentum Myrtle or Common Myrtle. Plant this compact, bushy myrtle in smaller gardens where it will grow about three to six feet tall and three to six feet wide.‘Tarentina Variegata’ has a similar growth habit to the original Tarentina and showcases pale yellow leaves with green streaks.‘Nana’ has especially small leaves and grows about 5 feet tall.‘Compacta’ is a dwarf variety like those listed above, but the ‘Compacta’ will reach anywhere from 6 to 8 feet.‘Compacta Variegata’ has a similar growth habit to the original Compacta, with chimeral yellow to white foliage variegation.‘Buxifolia’ is a very low dwarf variety with very small leaves.
Propagating Common Myrtle
Propagate by seeds or semi-hardwood cuttings in summer. Sow seed under a cold frame in autumn. When new growth begins to firm up, clip non-flowering shoots. If a shoot is flowering, remove the buds first. Plant in a 50/50 mixture of sand and compost out of direct sunlight. Rooting takes six to 12 weeks. Pot each specimen in gritty compost and overwinter indoors in a frost-free location. Transplant outdoors or indoors in spring.
Potting and Repotting Common Myrtle Tree Indoors
The common myrtle can be trained in many bonsai styles, especially broom-style. Every two or three years, repot younger myrtles. Every three to five years, repot the older ones that have been producing more flowers and are likely getting a bit rootbound. Like the water, the soil mix needs to be lime-free. Add some peat or Kanuma to a normal soil mix.
Pruning
Prune after the bloom period. To encourage the tree to grow small, remove spent blooms and clean any dead or diseased wood. To create a hedge, sheer the plant to the desired size. Naturally, bonsai and topiary forms require more pruning from infancy. Cut back a new shoot only if it has between six to eight pairs of leaves and at least one of the pairs has buds. Mend large wounds with cut paste. Young shoots and twigs can be mended and trained with wire because they are flexible and less prone to breakage.
Common Pests and Plant Diseases
Generally, the common myrtle is pest-free outdoors. Sooty mold, which is the “honeydew” excrement from pests, can develop on the foliage to indicate a small-scale insect invasion of sucking insects, such as whiteflies, aphids, and mealybugs. Thrips and spider mites may also appear but in hot, dry weather. An indoor bonsai could be prone to an attack by pests, especially in a warm room that lacks light and moisture in the air.
