Agonis flexuosa is a medium sized robust tree belonging to the Agonis genus. They grow in south Western Australia. These trees are commonly seen on road verges and in parks in different places of Western Australia including Perth. This species is also known as Willow Myrtle, Swan River Peppermint and Western Australian Peppermint. However, they are better known by their scientific name Agonis flexuosa.
Agonis flexuosa Description
This vigorous evergreen plant have a very graceful and attractive appearance having decorative value. Here is its general description:
Height: The medium sized trees can grow up to 15 meters in height; however, they usually do not grow above 10 meters.
Bark: They have brown fibrous bark.
Foliage: Their foliage looks similar to that of weeping willow because they have the same weeping habit.
Leaves: The dull green narrow leaves of Agonis flexuosa trees grow approximately 150 mm in length.
Flowers: Small white flowers form the tightly clustered inflorescences in the axes. Flowers bloom between August and December. The white flowers growing in long clusters make the trees look very graceful.
Fruits: Their 3 to 4 mm wide fruits grow as hard capsules. The fruits have three valves containing small seeds.
Agonis flexuosa Distribution
The Western Australian Peppermint trees grow in the coastal and sub coastal regions of south Western Australia. Their northern range of distribution extends to northern Perth while the southern range extends to the Swan Coastal Plain.
Agonis flexuosa Varieties and Cultivars
The two recognized cultivars of the Peppermint tree are:
- Agonis flexuosa var. flexuosa
- Agonis flexuosa var. latifolia
Popular cultivars of these evergreen trees include
- Agonis flexuosa ‘Nana’
- Agonis flexuosa ‘Burgundy’ or Burgundy Willow Myrtle
- Agonis flexuosa ‘After Dark’ or After Dark Peppermint Tree
Agonis flexuosa Growing Conditions
Soil: They can grow in many types of soils but well-drained sandy soils are ideal for their growth.
Soil pH Requirements: The pH level of the soil should ideally be between 5.5 and 6.5.
Sunlight: Direct sunlight is necessary for their proper growth.
Temperature: Agonis flexuosa trees are draught tolerant. They can also survive in extreme cold temperatures between 25 °F and 30 °F.
Climate: Temperate climates are ideal for their proper growth; however, they can adapt to other types of climates as well.
Water Requirements: Natural rainfall usually provides these trees with the required 1 inch of water. Otherwise they should be watered regularly.
Growing Agonis flexuosa (Willow Myrtle)
The evergreen Agonis flexuosa trees are widely used in mass-planting. They are grown to add to the natural beauty of parks and roads mainly in Western Australia. They have also been introduced to the Rottenest Island. These low maintenance weepy trees have a fast growth rate. They can be easily propagated form seeds. No pretreatment is necessary for the seeds before sowing.
One should dig out a wide area (3 to 4 times the diameter of the root ball of the plant) for planting a small Agonis flexuosa tree. Container grown trees should be planted by laying them on their side before removing the container. Then the hole should be filled in with soil. Mulched soil helps the plants to grow faster. So, one should apply a 3 inch layer of compost to the soil.
Staking depends on the flexibility and size of the Agonis flexuosa trees. Generally, only the trees planted in exposed and windy locations need staking. Low stakes are preferred for them as this allows the trees to develop more naturally. However, higher stakes are used for trees located in extremely windy areas. Staking should not be done in a way that the tree stem and branches do not have enough space to move forward and backward in wind. Researches show that these movements help the trees grow strong roots that prevent the tree from falling over during storms.
Young Willow Myrtle plants need plenty of phosphorus for proper development of their roots. Due to this reason, they should be provided with phosphorus rich fertilizers during the first season of growth. All purpose fertilizers can be beneficial for established trees. However, fertilizing them during the later part of the growing season should be avoided. Because the vegetative growth caused by this late fertilization will not be able to survive the cold weather.
The soil should be kept moist with regular watering but it should not have any drainage problems as Agonis flexuosa trees need well-drained soil. There is no need to water them at times of sufficient rainfall. However, one should water them when natural rainfall is not providing the preferred 1 inch of water. Care should be taken not to overwater them as this will lead to plant diseases like rotting of stem and root due to oxygen deprivation. Although one should not wait for the plants to wilt before watering them as the plants might not be able to recover. The first two years of growth are critical for Agonis flexuosa trees. It is better to water deeply once a week than to water for a few minutes every day. Thorough watering is the key for their good health and proper growth. Lack of watering will cause the roots to wither and die.
Agonis flexuosa Pests and Diseases
Common pests like spider mites and scales may attack these evergreen trees. Spider mites thrive in dry, hot conditions. Dry air may worsen the problem of pests, so it is important to water the plants regularly. Insecticides recommended by garden experts can be used. Natural enemies of these insects like ladybug larvae and parasitic wasps might help in fighting the pest problems.
Agonis flexuosa Interesting Facts
Here are some interesting facts about them:
- They are among the most seen and recognized trees on the roadsides and in parks of Western Australia.
- Their name “Agonis” is originally derived from “agon” which means “gathering” or “collection” in Greek. This probably refers to the flower clusters of these trees.
- Their leaves have a strong peppermint-like aroma. Due to this reason they are also known as Peppermint trees.
The beautiful evergreen Agonis flexuosa trees can be an admirable addition to any park or lawn. The attractive yellow flowers can also be used for indoor decoration. The low maintenance trees adorn many parks and roadsides of Western Australia.
Agonis flexuosa Pictures
Here are some images of the beautiful Agonis flexuosa trees: