Overview
Arctostaphylos nummularia Gray ssp. sensitiva (Jepson) P.V. Wells is a plant species in the Ericaceae family. This evergreen shrub is usually found in rocky areas on serpentine soils in California. It is a rare species that has been designated as a California Native Plant Society List 1B species, indicating that it is rare, threatened, or endangered in California.Common Names
Arctostaphylos nummularia Gray ssp. sensitiva is commonly referred to as sensitive manzanita, as it is sensitive to disturbances in its environment, and its delicate branches can easily be damaged.Appearance
The sensitive manzanita typically grows up to 6 feet high and wide. It has smooth, reddish-brown bark with a gnarled, twisted appearance. Its leaves are small, oval-shaped, and usually measure between 0.2 and 0.7 inches long. The plant's flowers are small, pinkish-white, and bell-shaped. They bloom in the winter and spring months. Its fruit is a small, edible berry that is green when unripe and turns red as it ripens.Uses
Historically, the Pomo Indians used the sensitive manzanita for its medicinal properties. They boiled its leaves and drank the tea to treat ailments such as fever and stomach cramps. Nowadays, the plant is primarily used for ornamental purposes due to its attractive appearance. It is also useful in erosion control and habitat restoration efforts due to its ability to grow in poor soil conditions. Additionally, the plant serves as a valuable food source for wildlife, including birds and small mammals.Light Requirements
Arctostaphylos nummularia Gray ssp. sensitiva requires full sunlight to thrive. It can tolerate partial shade, but areas with high shade are unsuitable for the plant. In areas with insufficient sunlight, the plant can experience stunting of growth or even die back.
Temperature Requirements
This plant prefers a mild climate with temperate temperatures. It can tolerate brief periods of freezing temperatures, but extended periods of frost can cause damage or even kill the plant. Arctostaphylos nummularia Gray ssp. sensitiva prefers temperatures ranging from 60-80°F (15-27°C).
Soil Requirements
The ideal soil for Arctostaphylos nummularia Gray ssp. sensitiva should be acidic and well-draining. The plant prefers loose, sandy soil with good drainage. It can also tolerate rocky locations, but the soil must not be compacted. The addition of organic matter can help improve the soil quality and provide nutrients for the plant.
Cultivation methods
Arctostaphylos nummularia Gray ssp. sensitiva, also known as sensitive brittle-leaf manzanita, is a small evergreen shrub that is endemic to California. This plant thrives in well-drained, sandy soils that are slightly acidic. The ideal location for planting is in full sun or partial shade. It can tolerate coastal fog, but it is sensitive to high humidity.
Propagation of A. nummularia can be done through seeds or cuttings. The seeds require cold stratification to germinate, while cuttings can be taken in the late summer through early fall. Once planted, the plant should be watered regularly until it gets established. It is also important to mulch around the base to help retain moisture and suppress weed growth.
Watering needs
A. nummularia requires consistent but moderate watering. While it is drought-tolerant, young plants need regular irrigation until they establish a deep root system. You should water it deeply but infrequently to encourage deep root growth. The ideal watering frequency is once every two weeks during the growing season for mature shrubs. Watering should be reduced in the winter to prevent root rot.
Fertilization
Arctostaphylos nummularia does not require a lot of fertilizer. You can use a general-purpose fertilizer once a year in the early spring after all chance of frost has passed. Applying too much fertilizer can result in excessive growth, which can weaken the plant. The plant is adapted to extract nutrients from nutrient-poor soils, so it doesn't need much fertilizer.
Pruning
Pruning is not required for A. nummularia. It has a naturally dense and compact growth habit, and it does not require shaping. However, if the plant is getting too large or has dead or damaged branches, you can prune it in late winter or early spring. You should remove no more than 1/3 of the plant's growth during a single pruning session. Regular pruning helps to keep the plant healthy and blooming.
Propagation of Arctostaphylos nummularia Gray ssp. sensitiva (Jepson) P.V. Wells
Arctostaphylos nummularia Gray ssp. sensitiva (Jepson) P.V. Wells can be propagated through several methods. Here are some of the ways:
Seed Propagation
Propagation of Arctostaphylos nummularia Gray ssp. sensitiva (Jepson) P.V. Wells by seeds is the most commonly used method. The seeds can be collected from ripe berries and sown in a well-draining compost mix. They should be kept moist and warm, and germination should occur in two to three months. Once the seedlings are large enough, they can be transplanted into individual pots or suitable planting locations.
Cuttings
This plant can also be propagated by cuttings. Several cuttings can be taken from a healthy stem of the parent plant and planted in a rooting hormone and compost mix. It is important to ensure that the cutting has at least three leaves and is around 4-6 inches long. The cuttings should be kept in a shaded area and regularly misted. After 3-4 weeks, the cuttings should have roots, and they can be transplanted into individual pots or planting locations.
Layering
Layering is another propagation method that can be used for Arctostaphylos nummularia Gray ssp. sensitiva (Jepson) P.V. Wells. This method involves bending a branch of the plant and pinning it down to the soil so that it is in contact with the ground. After some time, roots should start to emerge from the buried part of the branch. The branch can then be cut from the parent plant, and the new individual can be transplanted into any suitable location.
Disease Management
Arctostaphylos nummularia Gray ssp. sensitiva (Jepson) P.V. Wells is generally a hardy plant that is not prone to many diseases. However, there are a few diseases that may affect this plant, including:
- Phytophthora root rot
- Canker diseases
- Powdery mildew
Phytophthora root rot is a soil-borne disease caused by a fungus-like organism that leads to the plant's death. To prevent this disease, it is essential to avoid overwatering and maintain good drainage. Applying fungicides may also be effective in managing this disease.
Canker diseases can cause stem and twig dieback that may affect plant growth and productivity. To manage canker diseases, it is essential to prune affected plant parts along with applying fungicides to the healthy parts of the plant to avoid the disease's spread.
Powdery mildew is a fungal disease that causes a white, powdery coating on the plant's surface. To eliminate powdery mildew, it is essential to prune affected parts of the plant, apply a fungicide, and maintaining good air circulation.
Pest Management
Arctostaphylos nummularia Gray ssp. sensitiva (Jepson) P.V. Wells is generally not prone to many pests. However, some pests that may affect this plant are:
- Spider mites
- Scales insects
- Caterpillars
Spider mites are tiny pests that damage the plant's color by piercing through the plant tissue to suck out sap from the plant. To prevent this pest from damaging the plant, it is essential to wash the leaves with water regularly, removing affected plant parts, applying insecticidal soap, and maintaining the plant's moisture level.
Scales insects are tiny, immobile pests that attach themselves to the plant and remove sap from the plant, causing yellowing of leaves and stunted plant growth. To eliminate scales insects, it is essential to remove them manually using cotton swabs and alcohol or insecticidal soap.
Caterpillars are pests that can cause damage to the plant by feeding on plant tissue. To prevent caterpillars from damaging the plant, it is essential to remove them manually, spray the plant with insecticides and apply Bacillus thuringiensis, which is a biological spray that targets caterpillars' larvae.
