How to Grow and Care for Ctenanthe Setosa 'Grey Star'

Ctenanthe (pronounced te-NANTH-ee) plants are famous for their striking variegated foliage, and the cultivar Ctenanthe setosa 'Grey Star' is no exception. It is a clump-forming plant with long oblong leaves, grey with darker green veins. Although it can produce white blooms when grown indoors, 'Grey Star' rarely flowers—this plant is all about the dramatic foliage. This evergreen, clump-forming, herbaceous perennial has large, thick leaves that feature dark green and silvery-gray stripes on the top. The undersides are also beautiful with their distinctive purple or maroon shades. Although it can be grown as a garden plant in zones 10 to 11, in most regions Ctananthe plants are usually grown as houseplants. 'Grey Star' is a slow-growing plant that is usually planted in late spring or early summer when used as a garden plant.

Ctenanthe Setosa 'Grey Star' Care

Related to Calathea and Stromanthe, this is another tropical plant that thrives in a warm, moist, and shady environment. Providing your Ctenanthe setosa 'Grey Star' gets enough shade, warmth, and moisture, these plants can thrive.

It's also a good idea to periodically wipe down the foliage with a damp cloth. Cleaning away any dust not only gives the leaves a brighter appearance, but it allows them to breathe fully.

Light

Too much direct sunlight can result in fading colors on the leaves of Ctenanthe setosa 'Grey Star'. Provide the plant with a sheltered spot that gets bright but indirect sunlight to ensure the most dramatic foliage display. Too much shade can also result in diminished variegation and leggy growth. Place the plant in bright, in-direct light for best results.

Soil

This houseplant requires a well-drained potting mix with good aeration to ensure the right combination of drainage and moisture retention. Add perlite to mix for good drainage. Use a mix with good nutrients, as this is important for a plant that has such large and colorful foliage.

Water

The right amount and temperature of water will ensure healthy foliage development. If you are using this plant in the garden, during the warm summer growing season, the soil should remain moist but never waterlogged. Too much water and poor drainage can quickly lead to root rot and leaf fungal issues.

Generally watering around twice weekly is to be expected, but you should properly test the soil to make sure it is not already feeling soggy. When the top 1 to 2 inches of soil is dry, that's when it's time to water the plant. Water it slowly and only until the water begins to drain from the pot. Remove the excess water so the plant is not sitting in any water. Some enthusiasts use rainwater for their 'Grey Star' houseplants to avoid potentially damaging the roots with the chloride and fluoride found in tap water.

Once you move into winter, the top of the soil can be allowed to dry slightly, and the frequency of irrigation should drop considerably. Make sure the water used in this colder season is at room temperature, as overly cold water will cause problems with the plant's sensitive roots.

Temperature and Humidity

Ideal temperatures are between 60 and 80 degrees Fahrenheit. All Ctenanthe species need plenty of humidity to thrive.

If you like to keep the air conditioning or heating on high throughout your home, you might find it challenging to successfully grow Ctenanthe setosa 'Grey Star' as a houseplant. They can't handle dramatic changes in temperatures and don't do well with drafts or dry air. Make sure to place the plant away from vents.

Increase the humidity by putting your plant on top of a pebble tray so that the water can gather there without soaking the roots. A humidifier is also a worthwhile investment if you are a tropical houseplant fan.

Fertilizer

Plants with large, lush leaves like Ctenanthe setosa 'Grey Star' generally benefit from regular feeding with a weak liquid fertilizer during the growing season. Feeding can also be halted in the fall and winter when the plant's growth slows and stops.

Types of Ctenanthe

In addition to Ctenanthe setosa 'Grey Star' and other cultivars, there are several other species of Ctenanthe you can consider:

• Ctenanthe lubbersiana: This species grows to about 18 inches tall with elliptical leaves that have a green and creamy yellow pattern and pale green undersides
• C. oppenheimiana: This species grows to 3 feet tall with thinner lance-shaped leaves, which include dark green and silver tops and maroon undersides, A popular cultivar is 'Tricolor'.
• C. burle-marxii: A compact plant with elliptical leaves that have silvery gray and green stripes.
  

Pruning

The only pruning this plant needs is removing damaged or dying foliage. This tends to happen with the older leaves towards the base of the stem. Trimming these off will direct all the plant's energy into young growth.

Propagating Ctenanthe Setosa 'Grey Star'

Ctenanthe setosa 'Grey Star' is easy to propagate from stem cuttings or offsets, both of which will produce a copy of the mother plant, rather than trying to find rare seeds to grow the plant. Here are steps for both methods.

How to propagate with stem cuttings:

1. Find a cutting that is around 5 inches long and taken from a healthy stem with around four leaves. Cut it just below a leaf node with a sharp, sterilized cutting tool.
2. Strip the leaves from the bottom half of the stem and dip that end in rooting hormone.
3. Place the stem in a 4-inch pot with drainage holes and filled with potting soil.
4. Place a clear plastic baggie over the stem to keep in the moisture and humidity. Make a couple of tiny slits at the top for the plant to breathe.
5. Keep the soil moist and after a few weeks, tug on the cutting to see if roots have developed. If so, remove the plastic.
6. Transfer to a larger pot when the roots are solid.
   

How to propagate with offsets:

Propagating with offsets (or offshoots) is extremely easy and simple. If you have an established plant, you may suddenly seed new pups emerging from the pot. You can easily harvest these pups to create new plants. Typically done in spring.

1. Gently remove the plant from the pot.
2. Locate the offset (pup) that you want to remove from parent plant.
3. Brush away soil from the basal offset to see the root system.
4. Use a clean, sharp knife to cut the stem with at least two root stands attached to the base.
5. Prepare a small pot (around 8 inches) by filling it with the potting medium and perlite. Mix in a tablespoon starter fertilizer and mix.
6. Prepare a hole in the middle of the soil. Place the roots/pup in the pot.
7. Moisten the soil, but do not drench the plant.
8. Put the plant in indirect lighting in a warm spot with high humidity.
   

Potting and Repotting Ctenanthe Setosa 'Grey Star'

Because these plants can grow fast and tall in the right conditions, they will benefit from being repotted every few years to ensure they have adequate space. Choose a large pot of any material, but make sure it has decent drainage holes to prevent water from sitting around the plant's roots.

Common Pests & Plant Diseases

Spider mites and mealybugs are the two main culprits that bother Ctenanthe setosa. You'll know your plant has nearly transparent spider mites if you spot tiny spider webs or small yellow bumps on the underside of the leaves. You may also find evidence of scale, thrips, and whiteflies on the plant.

The common plant diseases that may bother Ctenanthe include root rot, leaf spot, botrytis, leaf rust, and powdery mildew. Some of the problems may stem from soggy soil conditions.

Common Problems With Ctenanthe Setosa 'Grey Star'

This plant has a reputation for its finicky nature. But there are three especially critical problems you might encounter with its leaves. If you quickly address the issues, the plant may possibly survive.

Loss of Plant Leaves

The most common problem with Ctenanthe setosa 'Grey Star' is dehydration. If the plant is very dry, its beautiful leaves will begin to crimp up and then drop off the plant completely. If the problem is not treated, the entire plant may begin to shrivel up. Instead of trying to revive the plant with a flood of water, give it small doses so it does not go into shock. Tiny waterings every day or two sometimes bring the plant back to life.

Leaves Drooping

Droopy leaves that are soft to the touch may mean the plant is being overwatered. Leaves may start to drop off from too much water, as well. This plant definitely does not like to sit in water. If the soil is waterlogged, make sure the drainage hole isn't plugged. Gently replace the soil with a dry mix. Carefully trim away rotted portions of the roots with a sterilized cutting tool. Though it could take some time, the plant may recover.

Leaves Turning Yellow/Brown

If the leaves of your 'Grey Star' turn yellow and brown, that means the plant is scorched by too much direct sunlight. Trim the scorched leaves and relocate your plant to a bright area that does not have direct light.