Origin and Common Names
Eucalyptus pachyphylla is a species of eucalyptus that is commonly known as the thick-leaved mallee or pachyphylla gum. The plant is native to Western Australia, particularly the northern and eastern parts of the state.
Appearance
Eucalyptus pachyphylla is a small to medium-sized tree or mallee that typically grows up to 10 metres in height and 7 metres in width. The tree has a lignotuber at its base, which allows it to regenerate after bushfires. The trunk of the tree is usually smooth and white, shedding bark in thin flakes. The foliage is grey-green in colour and the leaves are thick and leathery, measuring around 4-10 cm in length and 1-3 cm in width. The gum nuts are cylindrical in shape and measure around 1-2 cm in length and 0.8-1.2 cm in width.
Uses
Aboriginal Australians have traditionally used Eucalyptus pachyphylla for medicinal purposes, to ease sore throats, colds, and coughs. The leaves of the plant are also used as natural insecticides, and the oil extracted from the leaves can be used as a natural remedy for various ailments. Eucalyptus pachyphylla is also used as an ornamental plant in parks, gardens, and as street trees due to its attractive appearance, and in some parts of Western Australia, its wood can be used as a source of firewood or for making charcoal.
Light Requirements
Eucalyptus pachyphylla, commonly known as the thick-leaved mallee, requires full sunlight to grow and thrive. It cannot grow successfully in shady areas as it needs direct sunlight for at least six hours a day.
Temperature Requirements
Eucalyptus pachyphylla grows well in warm to hot climates. It can tolerate temperatures as low as 20°F (-6°C) but prefers average temperatures of 50-80°F (10-27°C). This plant can endure harsh conditions like drought and heatwaves but cannot handle frost.
Soil Requirements
Eucalyptus pachyphylla prefers well-drained soil with good water-holding capacity. Loamy or sandy loam soil with a pH range of 5.5 to 7.5 is an ideal growing medium for this plant. It is drought-tolerant and doesn't like wet soils. It can efficiently grow in soils with poor fertility and gravelly soils, as long as they are not waterlogged.
Cultivation methods
Eucalyptus pachyphylla, commonly known as the thick-leaved mallee, is a drought-tolerant plant that is primarily grown for its ornamental value. It can be propagated through seed and cutting. For seed propagation, sow the seeds in a well-drained soil mix that has good water retention capacity. Cover the seeds lightly with soil and keep the soil moist at all times until germination, which may take two to four weeks. For cutting propagation, take semi-hardwood cuttings in summer and dip the ends in rooting hormone before planting them in a well-draining potting mix. Provide them with shade and consistent moisture until the roots develop.
Watering needs
Eucalyptus pachyphylla is a drought-tolerant plant, but it still requires consistent watering during the first few years of growth until it is established. Water the plant deeply at least once a week or when the soil is dry to a depth of 2-3 inches. During hot and dry weather, the plant may require more frequent watering. Reduce watering during the cooler months, but do not let the soil dry out completely.
Fertilization
Eucalyptus pachyphylla does not need regular fertilization and may even grow better in poor soils. However, if you want to improve its growth and health, you can add a slow-release fertilizer that is low in nitrogen and high in phosphorus and potassium in early spring. Avoid fertilizing in the first year of growth. Apply the fertilizer according to the manufacturer's instructions and water well after application.
Pruning
Eucalyptus pachyphylla does not require regular pruning but may benefit from occasional shaping or thinning. Prune the plant in late winter or early spring before the new growth appears. Remove any dead, diseased, or crossed branches to improve the plant's structure. If you want to shape the tree, prune the leaders and side branches as desired. Avoid over-pruning as this may stress the plant and lead to poor growth or even death.
Propagation of Eucalyptus pachyphylla
Eucalyptus pachyphylla, commonly known as the "Red-budded Mallee," is a small multi-stemmed tree or mallee that is native to Western Australia. Propagation of this species can be achieved through various methods, including seed propagation, cuttings, and grafting.
Seed Propagation
Propagation of Eucalyptus pachyphylla through seeds is relatively simple. The seeds of this species are small and must be collected when they are ripe. To propagate through seed, the seeds should be germinated in a well-draining soil mix and maintained at a constant temperature of around 20-22°C. The germination process can take up to three weeks, and it is important to keep the soil moist but not wet. Once the seedlings have reached a suitable size, they can be transplanted into their permanent locations.
Cuttings
Propagation through cuttings is another method used to propagate Eucalyptus pachyphylla. Softwood cuttings taken in the early spring have the highest rate of success. Cuttings should be around 10-15cm long and taken from the current year's growth. Remove all leaves from the lower portion of the cutting, leaving a few leaves at the top, and place the cutting in a rooting hormone. Insert the cutting in a well-draining soil mix and cover with plastic to maintain humidity. Rooting should take place in around four to six weeks, and once the roots have formed, the cutting can be transplanted to its permanent location.
Grafting
Grafting is another method used to propagate Eucalyptus pachyphylla. This method involves taking a cutting of the desired cultivar and attaching it to a rootstock of a related Eucalyptus species. Grafting should be done in early spring and using a rootstock of around 10mm in diameter. The graft should be made using an omega or whip graft, and the union should be wrapped with grafting tape. Once the graft has taken and the union has grown together, the plant can be transplanted to its permanent location. Grafting is commonly used to propagate cultivars that do not perform well when propagated through seeds or cuttings.
Disease and Pest Management for Eucalyptus Pachyphylla
Eucalyptus pachyphylla, commonly known as the thick-leaved mallee, is a native plant of Australia and a popular choice for landscaping. However, just like any other plant, it is susceptible to diseases and pests which can affect its growth and overall health. Here are some of the common ones and their management:
Diseases
Phytophthora Root Rot: This is a soil-borne disease caused by a fungus-like organism. It can cause wilting, yellowing of leaves, and eventual death of the plant. To control it, avoid planting in poorly drained soils, ensure proper soil aeration, and reduce irrigation water.
Leaf Spot: This is a fungal disease that manifests as small, round, black or brown spots on leaves. It can lead to defoliation and stunted growth. Control measures include removing infected leaves, proper plant spacing, and applying fungicides.
Canker: This is a bacterial disease that causes sunken, target-shaped lesions on the bark. It can result in branch dieback and death of the plant. Control measures include pruning infected branches and applying a copper-based fungicide.
Pests
Eucalyptus Weevils: These are small, black beetles that feed on leaves and cause notching and defoliation. They can be controlled by spraying with insecticides or by introducing natural predators such as ladybugs.
Leafhoppers: These are small insects that suck sap from leaves, leading to yellowing and stunted growth. They can be controlled by using insecticidal soaps or oils.
Eucalyptus Longhorned Borers: These are large beetles that bore into the trunk and branches, causing extensive damage. Control measures include using insecticidal sprays or trunk injections of systemic insecticides.
Regular monitoring of the plant for signs of diseases and pests, along with proper cultural practices like pruning and fertilization, can help maintain the health and vigor of Eucalyptus pachyphylla. Consult with a local horticulturist for further information and advice.
