Periglossum macrum
Periglossum macrum (E. Mey.) Decne. is a species of orchid that is native to Madagascar, Comoros, and the Mascarene Islands. Common names for this plant include Giant Orchid and Perfumed Periglossum.
General Appearance
The Periglossum macrum plant typically has a terrestrial growth habit and can attain heights up to 150 centimeters. This species produces tall spikes that bear many bright yellow, green, or white flowers that are about 3 centimeters wide. The oval-shaped pseudobulbs at the base of the plant can store water and energy when rainfall is scarce.
Uses
Periglossum macrum is used primarily for ornamental purposes. The plant's striking appearance, coupled with its sweet fragrance, make it a popular choice for gardens and indoor spaces. In some areas of Madagascar, the pseudobulbs of this plant are used in traditional medicine to treat headaches and stomachaches.
Light Requirements
Periglossum macrum requires bright, indirect light. Direct sunlight can scorch the leaves, but too little light will cause the plant to weaken and eventually die. It is best to place the plant near a window with filtered sunlight or supplement with artificial light if necessary.
Temperature Requirements
The ideal temperature range for Periglossum macrum is between 60-80°F (15-27°C). Sudden changes in temperature or prolonged exposure to extreme temperatures can cause stress to the plant and affect its growth. Avoid placing the plant near drafts or heating/cooling vents.
Soil Requirements
Periglossum macrum prefers well-draining soil that is slightly acidic (pH 5.5-6.5). A mixture of peat moss, perlite, and coarse sand will allow for proper drainage and root aeration. It is important to avoid overwatering, as this can lead to root rot. Allow the soil to dry out slightly between waterings.
Cultivation
Periglossum macrum plants grow well in a sunny spot or partial shade. It prefers well-draining soil, which allows the water to penetrate deep into the soil and dries quickly. The soil for the plant needs to be slightly acidic with a pH of around 5.5 to 6.0.
The plant does well in a pot, and the pot should have a good drainage system. The size of the pot should be about twice the size of the root ball.
Watering Needs
Periglossum macrum requires regular watering, but avoid overwatering. Water the plant when the top inch of soil feels dry, and ensure there's good drainage. During the winter months, water the plant sparingly as this is its resting stage.
Periglossum macrum requires moderate humidity to grow well. You may use a humidifier or place the plant in a tray filled with pebbles and water, keeping the plant on top of the pebbles.
Fertilization
Feed the plant once every month with a balanced fertilizer diluted at half-strength. During winter, reduce the frequency to once every 2 months. Overfertilization can damage the plant.
Pruning
When the flowers have withered, the stem can be pruned from the base. Old stems can also be pruned during repotting to promote the growth of new roots. To prevent the spread of diseases, use sterilized pruning equipment before and after pruning.
Periglossum macrum also needs to be repotted every two years. It's best to repot during the spring. Treat the roots with care and ensure not to damage them. Use fresh potting mix when repotting the plant.
Propagation of Periglossum macrum
Periglossum macrum (E.Mey.) Decne., commonly known as the Yellow Spider Orchid, is a terrestrial orchid that is native to the southern and southwestern parts of Africa. It is a fairly easy plant to grow, and propagating it can be done through various methods.
Seed Propagation
Propagation by seed is the most common method for Periglossum macrum, and it is relatively easy to do. The best time to sow the seeds is during the growing season, preferably from late spring to early summer. The seeds should be sown in a well-draining soil mix, and should be covered lightly with sifted sand or vermiculite. Keep the soil evenly moist, and the seeds should germinate within three to six weeks. After the seedlings have produced two or three leaves, they can be transplanted into individual pots.
Division Propagation
Another way to propagate Periglossum macrum is through division. This method involves dividing the plant at the root level into several smaller sections, each with their own roots and growth points. It is best to do this during the plant's dormant period, which is usually in the autumn or winter. Simply gently dig up the plant and carefully divide it into sections. Each section should have at least one or two growth points, and should be replanted in well-draining soil mix at the same depth as it was before. Water regularly until new growth appears.
Keiki Propagation
Periglossum macrum can also be propagated through keikis, which are small plantlets that grow from the stem of the mother plant. This method is similar to division, but instead of dividing the plant at the root level, you cut off the keiki and replant it. Once the keiki has a few roots and a small growth point, it can be planted into its own pot with well-draining soil mix. Keiki propagation can be done at any time of the year, but it is best to do it during the growing season.
Disease and Pest Management for Periglossum Macrum
Periglossum Macrum is a beautiful plant that belongs to the family Orchidaceae. It is a terrestrial species which grows in the highland regions of South America and can be a little bit difficult to maintain. There are various diseases and pests that might affect the plant, but some of the most common ones include:
Fungal Diseases
Periglossum Macrum is susceptible to fungus diseases like anthracnose, rust, and leaf spot. These diseases usually manifest as yellow or black spots on the plant's leaves, and if left unchecked, they could lead to total leaf blight or the death of the plant. To manage fungal diseases, it is essential to maintain good hygiene by removing and destroying all infected plant debris, providing adequate ventilation, and utilizing fungicides.
Viral Diseases
Periglossum Macrum is also prone to viral diseases such as orchid fleck virus and tobacco ringspot virus, which cause a severe stunting of the plant and yellowing or mottling of the leaves. Unfortunately, there are no cures for viral infections, so it is recommended to maintain healthy plants, keep strict sanitation practices in place like disinfecting all cutting tools, and get rid of any infected plants to prevent the virus from spreading.
Root Pests
The plant can be infested by root pests, including mealybugs, spider mites, fungus gnats, and aphids. These pests usually feed on the plant's roots, making it difficult for the plant to absorb water and nutrients. Symptoms of infestation include wilting, yellowing, or stunted growth. To manage these pests, it is essential to use insecticidal sprays, apply beneficial nematodes to the soil, or utilize sticky traps.
Aerial Pests
Aerial pests such as spider mites, thrips, and scale insects, can also infest the plant's leaves and stems. These pests usually feed on the plant's sap, resulting in a reduction of vigour. The symptoms of infestation include yellow spots, leaf distortion, or wilted leaves. To manage aerial pests, it is essential to wash the plant regularly with water or apply insecticidal sprays.
In summary, preventing disease and pest infestations in Periglossum Macrum requires maintaining good hygiene through regular cleaning, routine check-ups and applying organic pesticides and fungicides. By following good plant hygiene and applying preventative measures, one can successfully manage the common diseases and pests that afflict this beautiful plant.
