Overview
Diplazium expansum Willd. is a perennial fern species that belongs to the family Athyriaceae. It is a large-sized fern that can grow up to 1.5 m tall. The plant is native to the tropical and subtropical regions of Asia, Africa, and Oceania.
Common Names
Diplazium expansum Willd. is commonly known as the Large Coastal Wood Fern, Shoulder Fern, or Tamanu Fern. In Indonesia, it is also referred to as Paku Belawang.
Appearance
The fronds of Diplazium expansum Willd. are large, erect, and arching. They resemble the shape of a lance or a spearhead. The fronds can grow up to 1.5 m long and 25 cm wide. They are a bright green shade with a shiny texture, giving it a luxurious appearance. The plant has a central crown in which leaves emerge and spread out symmetrically. The spores of the fern are produced on the undersides of the fronds.
Uses
Diplazium expansum Willd. is commonly grown as an ornamental plant in gardens and landscaping. Its attractive, dense fronds provide a natural and earthy backdrop. The plant thrives in moist, well-drained soils. In some cultures, the rhizomes of the fern are used to treat various ailments such as rheumatism, toothache, and skin infections. It is also used as traditional medicine to relieve pain and inflammation.
Light Requirements
The plant Diplazium expansum Willd. typically requires moderate levels of light to thrive. It is a shade-loving plant, and direct exposure to sunlight can damage its fronds. It is recommended to place the plant in a location that receives bright, indirect light for optimal growth. It should be shielded from harsh afternoon sunlight as much as possible.
Temperature Requirements
The plant Diplazium expansum Willd. prefers moderate temperatures in the range of 15°C to 25°C. It cannot tolerate extreme temperatures and can get damaged if exposed to temperatures below 10°C or above 30°C. It is important to maintain a consistently warm and humid environment for the plant to ensure its growth and development.
Soil Requirements
Diplazium expansum Willd. grows best in well-draining, rich, and acidic soil. It requires soil that is high in organic matter and retains moisture well. The plant also thrives in slightly sandy soil. It is important to ensure that the soil is never waterlogged, as this can lead to root rot and damage the plant. Additionally, Diplazium expansum Willd. is sensitive to fertilizers, so it is recommended to use only organic fertilizers and in limited amounts.
Cultivation Methods
The Diplazium expansum Willd. plant is a tropical fern, commonly referred to as the spreading fern. It prefers to grow in a humid and warm environment with plenty of indirect sunlight and rich soil. You can grow it both indoors and outdoors, depending on the climatic conditions in your area.
If planting in the garden, you should ensure the soil is well-draining. Dig a hole twice as deep as the root ball and about three times the width. Add some compost or organic matter to enrich the soil, then plant the fern. Cover the roots with soil and tap the soil around the plant to firm it and remove air pockets.
For indoor cultivation, choose a pot with good drainage and put some gravel or stones into the bottom of the container to improve drainage. Mix your soil with some organic matter and fill the container two-thirds, add the fern, and top the soil up to the rim, leaving a watering well.
Watering Needs
Diplazium expansum Willd. requires consistent moisture to grow well. Water your fern every time the soil feels dry to the touch. As a rule of thumb, you should water your plant once or twice a week. Ensure that you do not over-water or under-water your fern.
When watering your fern, pour water into its base and avoid getting its foliage wet. The plant prefers distilled or rainwater to municipal tap water to minimize mineral buildup and maintain its moisture.
Fertilization
As a fast-growing plant, Diplazium expansum Willd. requires regular fertilizing to maintain its growth and health. You can use an organic fertilizer that contains phosphate, nitrogen, and potassium. Apply a balanced fertilizer once a fortnight during the growing season through to summer.
For the best results, fertilizer should be applied when the soil is moist to avoid fertilizer burn and over-feeding of the plant. You can also provide your fern with some compost or organic matter such as peat moss or leaf mold in the soil to support its growth.
Pruning
Pruning is essential for the health of your Diplazium expansum Willd. plant. It helps to remove any damaged, diseased, or dead leaves and maintain the plant's desired shape, size, and appearance.
Prune the fern regularly to promote new growth and prevent it from getting too big. Use a sharp pair of scissors or a pruning shear to cut the leaves and stems just above the soil line. You can prune your fern at any time of the year, but it’s recommended to do it during the spring or early summer.
Propagation of Diplazium expansum Willd.
Diplazium expansum Willd., also known as the large lace fern, is a gorgeous fern species that can be propagated by various methods, including spores, rhizome cuttings, and division.
Propagation by Spores
Propagation by spores is one of the most common methods of propagating Diplazium expansum Willd. Spores are reproductive units similar to seeds and are produced on the underside of mature fronds. To propagate the plant by spores, collect mature fronds, cut them at the base, and place them in a paper bag to dry for a few days. The spores will be released and can be sown on the surface of a sterile potting mix. Keep the soil moist and place the pot in a warm, humid area. After several weeks, small ferns will begin to emerge.
Propagation by Rhizome Cuttings
Diplazium expansum Willd. can also be propagated by rhizome cuttings. To do this, select healthy rhizomes and cut them into sections that are approximately 3 inches long. Then, plant the cuttings horizontally into a container filled with well-drained soil. Keep the soil moist and place the container in a warm, indirect light area. After several weeks, new shoots should emerge from the cuttings and develop into new plants.
Propagation by Division
Division is another method of propagating Diplazium expansum Willd. This method involves digging up an established plant and dividing the rhizomes into smaller sections. Each section should have at least one frond, and the roots should be intact. Then, plant each section in a container filled with well-drained soil. Keep the soil moist and place the container in a bright, indirect light area. After several weeks, new shoots should emerge from each section of the rhizomes and develop into new plants.
Disease and Pest Management for Diplazium expansum Willd.
Diplazium expansum Willd. is a tropical fern species that is known for its large, spreading fronds. While this plant is relatively hardy, it is still susceptible to a few diseases and pests that can impact its overall health. Here, we'll take a closer look at some of the most common issues you may encounter and provide tips for managing them.
Common Diseases
One of the most common diseases that can affect Diplazium expansum Willd. is leaf spot. This fungal disease is identified by the appearance of small, dark spots on the foliage. If left unchecked, these spots can grow and merge, eventually causing the leaves to die and fall off. To manage leaf spot, remove any infected leaves as soon as you notice them and dispose of them properly. Avoid getting water on the leaves when you water your plant, and make sure there is good air circulation around the plant to prevent the disease from spreading.
Another fungal disease that can impact Diplazium expansum Willd. is rust. Rust presents as reddish-brown spots on the undersides of the leaves, and can also cause yellowing and premature leaf drop. To manage rust, remove any infected leaves and dispose of them properly. Make sure the plant has plenty of light and good air flow, and avoid wetting the leaves when you water it.
Common Pests
The most common pests that can impact Diplazium expansum Willd. are spider mites and mealybugs. Spider mites are tiny insects that can cause a stippled, yellow appearance on the leaves, as well as webbing on the foliage. Mealybugs are small, white insects that gather along the veins and undersides of the leaves, and can cause stunted growth and yellowing of the foliage.
To manage spider mites and mealybugs, you can use a mixture of dish soap and water to create a natural insecticide. Simply mix a few drops of dish soap into a spray bottle of water and spray your plant, making sure to thoroughly coat the leaves. You can also wipe the leaves down with a damp cloth to physically remove the pests. If these methods don't work, there are also a number of commercially available insecticides you can use.
By being vigilant about disease and pest management, you can ensure that your Diplazium expansum Willd. stays healthy and vibrant. With proper care, this beautiful tropical fern will thrive in your home or garden for years to come.
