How to Grow and Care for Cat Whiskers Plant

Despite its common-sounding name, Cat Whiskers (Orthosiphon aristatus) traveled an exotic route before reaching American gardens. Native to China, Thailand, Malaysia, Indonesia, the Philippines, Papua New Guinea, and Australia, it is a perennial shrub that grows from 9 to 78 inches tall in the wild. Found along the edges of forests and thickets, it prefers full sun and warm temperatures.

In the garden, its height and conical-shaped, white or lavender, two-lipped blooms with hairy, whisker-like stamens, purplish stems, and dark green leaves make a statement in a perennial bed. The plant is hardy in zones 9-12 and is considered tropical.

Cat Whiskers Care

A member of the mint family, Cat Whiskers is a tropical plant that works well in a warm climate garden or as a potted annual in colder areas. Cat whiskers should be planted in an area of full sun in well-draining soil. Place the plant at the back of a bed because it has a shrub-like shape and can reach heights over six feet; however, most garden plants reach 2 to 3 feet each season.

The flower spikes offer a good source of nectar for hummingbirds and butterflies in a pollinator garden. It is an easy-care plant requiring moderate water levels and feeding.

Light

Cat Whiskers prefer full sun but can tolerate some light shade. The blooms will be more profuse if given sufficient sunlight.

Soil

The plant prefers neutral soil that is well-draining. If growing as a container annual, use good potting soil and a container with adequate drainage holes.

Water

Newly planted cat whiskers should be watered regularly until they become established. After they become well-settled, only moderate watering is required unless there are periods of extreme drought. Container-grown plants required more frequent watering.

Temperature and Humidity

As a tropical plant, cat whiskers requires warm temperatures and is not cold-tolerant. Warm, humid air will encourage bloom production. The unique flowers appear on new growth each spring as soon as the nighttime temps begin to warm and the days get a bit longer.

Fertilizer

If the soil is fertile, additional fertilization is not usually needed. To boost bloom production, work some compost into the soil or use a balanced fertilizer (8-8-8 NPK) during the growing season, especially on container-grown plants.

Types of Orthosiphon aristatus

• Orthosiphon aristatus var. aristatus: Native range is east Asia along the edges of forests and thickets.
• Orthosiphon aristatus var. velteri: Native range of this variety is Vietnam. It grows as a subshrub or shrub in the wet tropical biome.

Pruning

If you are growing cat whiskers as a perennial, remove spent blooms during the growing season. Before the warmer temperatures of spring, prune the stems back about one-third to encourage new growth and more blooms. In cooler zones, the foliage will die back when temperatures become colder. Cut the stems down to ground level.

Propagating Cat Whiskers

Propagation is usually done through stem cuttings.

1. Select young, healthy, vigorous, non-flowering shoots 6-8 inches long in mid to late summer.
2. Remove the lower leaves leaving one to two leaves on the cutting, then coat the cut end with a rooting hormone.
3. Place the cutting in a mixture of perlite and coarse sand, and keep the cutting moist and warm and in a shady location until roots develop.
4. After around 45 days, you can transplant the cutting into a large pot filled with a loam and sand mix and move to a partially sunny area.
5. Transplant to a permanent location in the spring.
6. Place plants 16-24 inches apart to accommodate its shrub form.

How to Grow Cat Whiskers From Seed

During the growing season, collect seedheads/pods when flowers fade and allow them to dry in a cool, dark place. Remove the seeds from the pods and store them in a small paper bag or envelope. About six weeks before your area's outside temperatures reach a point where you can safely leave the plants outdoors to harden off, you will want to start the process.

1. Fill your trays with your selected seed starting medium and moisten the medium until it is damp but not soaked.
2. With a pencil or other pointy object, make a hole about 1/8th of an inch deep and place one seed in each one of the seed tray's cells.
3. Place the tray on top of the heating mat in front of a sunny window and cover the tray.
4. Check daily to ensure the soil remains moist, misting with a spray bottle when needed.
5. Depending on the moisture content and temperature, your seeds should germinate in 5-10 days.
6. Keep covered until the plants touch the cover, at which point remove the cover and, if possible, let a fan blow on the plants.

When plants are around 5-6 inches, transplant them into individual pots taking care not to damage roots, and continue to water until transplanted. When the temperature outdoors reaches a steady 50° Fahrenheit at night, you can take the plants outdoors to allow them to harden up before planting. After a week or so of hardening up, you can transplant your Cat Whiskers to the garden or a container.

Overwintering

If you are growing cat whiskers in hardiness zones 9-12, you shouldn't have to do anything to overwinter the plant. The shrub is semi-deciduous and will drop some leaves during the winter but will not become completely bare.

If you live in zone 9 or lower when the foliage dies back, mulch around the plant to help protect it from cooler nights. Most container-grown plants should be considered annuals. You can take autumn cuttings or collect seeds to start new plants in the spring.

Common Pests and Plant Diseases

There are no known serious disease or pest problems for cat whiskers. It is important to keep the area free of weeds to encourage good air circulation and soil moisture levels around the shrubs.

How to Get Cat Whiskers to Bloom

Place the shrub in an area that receives 6 to 8 hours of sun daily for the most proficient blooming. Feed the plant well at the start of the spring growing season and again in mid-summer to prolong blooming. Remove spent blooms to help strengthen the plant.

Common Problems with Cat Whiskers

Cat whiskers can spread and overtake smaller plants in a perennial bed. Prune judiciously to keep them the size you desire.