Overview
Convolvulus sagittatus Thunb. var. grandiflorus, commonly known as Arrowleaf Bindweed or Large-flowered Convolvulus, is a species of flowering plant in the family Convolvulaceae.
Origin
The plant is native to South Africa, but it has been naturalized in many other parts of the world, including Australia and the southwestern United States.
Common Names
Arrowleaf Bindweed is commonly referred to by a variety of names including Large-flowered Convolvulus, Arrowhead Morning Glory, Bowtie Vine, and Sagittate Convolvulus.
Uses
Arrowleaf Bindweed is mostly grown as an ornamental plant for its showy flowers. The plant is also used in traditional medicine for treating various ailments, including headaches, respiratory problems, and skin irritations. The leaves and roots of the plant are known to have a laxative effect when consumed in large quantities.
Appearance
The plant has a trailing or climbing habit and can grow up to 4 feet long. The leaves of the plant are arrow-shaped, hence the name Arrowleaf Bindweed, and are often variegated with green and silver colors. The flowers of the plant are large and trumpet-shaped, measuring up to 3 inches in diameter, and come in shades of pink, white, and purple. The plant blooms in the summer and fall.
Arrowleaf Bindweed is a hardy plant that prefers full sunlight and well-drained soil. It is drought-tolerant and can thrive in a wide range of soil types.
Light Requirements
Convolvulus sagittatus Thunb. var. grandiflorus is native to areas with full sun exposure, so it prefers bright and direct sunlight. It can withstand some shade but should be exposed to at least six hours of sunlight per day to thrive.
Temperature Requirements
The plant is well adapted to warm temperatures and can withstand extreme heat. It needs a minimum temperature of 18 degrees Celsius to grow properly and can tolerate temperatures as high as 40 degrees Celsius. On the other hand, it cannot thrive in areas with temperatures below -3 degrees Celsius.
Soil Requirements
Convolvulus sagittatus Thunb. var. grandiflorus prefers well-draining soils rich in organic matter. It can tolerate a wide range of soils, including sandy, loamy, and clay soils. The ideal soil pH should be slightly acidic to neutral, between 6.0-7.5. It is important to note that the plant cannot tolerate waterlogged soils because it limits root growth and development, which affects overall plant growth.
Cultivation Methods:
Convolvulus sagittatus Thunb. var. grandiflorus is primarily a hardy and drought-tolerant plant that thrives in full sun and well-draining soil. Therefore, planting it in a location that receives full sunlight is advised. It grows well in arid and semi-arid climates and is ideal for water-wise landscapes.
The ideal time for planting Convolvulus sagittatus Thunb. var. grandiflorus is in the spring season, when temperatures are still cool. The soil temperature should be at least 50 degrees Fahrenheit for successful germination to occur. Before planting, the soil should be loosened up to a depth of at least 8 inches. After planting, it is recommended to water the area immediately to enhance seedling establishment.
Watering Needs:
Once Convolvulus sagittatus Thunb. var. grandiflorus is established, it requires minimal watering as it is drought-tolerant. During the hotter months, it may require light watering once a week to maintain its growth. Overwatering should be avoided as it may lead to root rot. It is recommended to water the plant at the base to prevent the leaves from getting wet as it may lead to fungal infections.
Fertilization:
Convolvulus sagittatus Thunb. var. grandiflorus does not require frequent fertilization. Before planting, it is recommended to amend the soil with compost or well-rotted manure. This will provide the necessary nutrients required for growth. During the growing season, a light application of a low-nitrogen fertilizer may be added to enhance blooming. It is important not to over-fertilize as it may result in plant burn or excessive foliage growth.
Pruning:
Pruning Convolvulus sagittatus Thunb. var. grandiflorus is not necessary as it maintains a neat and tidy growth habit. However, if required, trimming it back after flowering can help maintain its form, prevent it from becoming straggly, and encourage vigorous growth. It is recommended to use sharp and sterilized pruning shears to prevent the risk of infections.
Propagation of Convolvulus sagittatus Thunb. var. grandiflorus
Convolvulus sagittatus Thunb. var. grandiflorus, commonly known as Large-flowered bindweed, can be propagated by several methods:
Seed propagation
The most common propagation method for Convolvulus sagittatus Thunb. var. grandiflorus is through seed. The plant produces seeds in a capsule-shaped fruit. These can be collected in the fall when the fruit is ripe, and the seeds have turned brown.
To propagate through seed, the collected seeds are sown in the seedbed without pre-treatment in the fall. They can also be sown in early spring. The seeds germinate in one to two weeks typically. Seedlings should be spaced at least two inches apart.
Cutting propagation
The plant can also be propagated through cuttings. To propagate through cuttings, cut a stem of about four inches from the parent plant. Remove the leaves from the lower two inches of the stem and insert it into a moistened rooting medium.
The cutting should be kept in a bright location out of direct sun, with a stable temperature of 60-70 F. After four to six weeks, the cutting should form roots, and it can be transplanted to a more substantial container.
Division propagation
Another method to propagate Convolvulus sagittatus Thunb. var. grandiflorus is through division. This method is best done in early spring or after flowering.
To propagate through division, gently dig around the parent plant to remove the root ball. This should be done carefully to prevent damage to the roots. Then divide the root ball into several smaller sections, each with several stems and roots. These sections can then be replanted in a well-draining soil mix in their location of choice.
Disease and Pest Management for Convolvulus sagittatus Thunb. var. grandiflorus
Convolvulus sagittatus Thunb. var. grandiflorus, commonly known as arrowleaf bindweed, is a hardy plant that is resistant to most diseases and pests. However, it can still fall prey to some common issues. Here are some diseases and pests that might affect the plant and ways to manage them.
Diseases
Powdery mildew: This fungal disease appears as a white powdery coating on the surface of leaves and stems. It can stunt the growth of the plant and reduce its yield. To manage powdery mildew, keep the plant well-ventilated and avoid overhead watering. Spraying with a fungicide like neem oil or potassium bicarbonate can also be effective.
Leaf spots: This is another fungal disease that presents itself as brown or black spots on the leaves. In severe cases, the leaves can turn yellow and fall off. To manage leaf spots, remove affected leaves promptly and dispose of them properly. Keep the plant dry and avoid overcrowding.
Pests
Aphids: These tiny insects pierce the leaves and suck the sap out, causing the leaves to yellow and curl. They also secrete a sticky substance called honeydew, which attracts mold. To manage aphids, wash the leaves with a strong jet of water or spray with insecticidal soap. Introducing beneficial insects like ladybugs or lacewings can also help control their population.
Spider mites: These pests are common in dry, hot weather. They cause yellowing and stippling of the leaves, and can eventually kill the plant if left untreated. To manage spider mites, increase the humidity around the plant by misting it regularly or placing a tray of water nearby. Spraying with insecticidal soap or neem oil can also be effective.
Regular monitoring of the plant is crucial in detecting any symptoms of diseases or pests. Early intervention is key to managing the issues and preventing them from spreading to other plants in the garden.
