Calathea Dottie (Black Rose) : Growing and Maintaining Guide

Are you bored with the common green tropical plants? Calathea Dottie will certainly give an unusual vibe into your mini jungle at home with its almost black leaves.

Surprisingly, this natural Calathea variety is relatively less fussy than other Calathea hybrids and cultivars. After 2 decades since its first creation, this plant is still going strong as a well-known houseplant.

By getting to know Calathea Dottie plants, you will understand why it is worth to have this under your care.

Overview

Although South America is the hometown of Calathea genus, Calathea Dottie does not exactly live in the wild. Based on a U.S. reputable database, Anne E. Lamb was the first person who created this plant. In 1998, Anne attempted to cultivate new variety using a tissue from Calathea roseapicta. Later in 2000, the patent was finally official.

This variety is different than others because Anne relied on the natural mutation in the process. Eventually, it produced a stable variety which is pretty much unique yet quite tolerant even for beginners.

Non-Toxic Plant

All Calatheas basically non-toxic for human and animals. Therefore, there would be no serious problem when little kids and pets like cats and dogs touch the plant.

Since its main purpose is as a decorative houseplant, eating their leaves is a bad decision. The plant might have pest or contain chemical substance from fertilizer or hard water. Moreover, this plant contains saponins that may cause mild irritation on the skin. In short, creating a distance between Calathea Dottie and your fur baby and lovely children would protect all.

In addition, this plant also works well as a natural air filter. Here, the plant converts carbon dioxide into oxygen. It naturally neutralizes specific toxin throughout the day, creating a healthier air around your living space.

Leaves

The large oval-shaped foliage starts in deep green in the young phase. Following the maturity, the leaf color turns bolder into almost black. On the surface, pink patterns decorate the veins and perimeter while deep purple dominates the undersides. For this reason, people call this plant, Black Rose.

In the daylight, the leaves stay horizontal to optimally absorb the sunlight. Once night comes, the lower light condition makes the leaves curl upward, showing off its contrasting undersides.

Do you know?

Despite its beautiful features, Calathea Dottie doesn’t lose its pink variegation as it continues to grow.

Flowers

In the wild, Calathea Dottie could produce small white flowers in summer months. For many, these flowers appear to be insignificant that you might overlook their presence.

Others try to invest their time and effort to make them bloom indoors. This is harder than it looks particularly in indoor setting. Without the right or almost perfect condition, the blooming probability is rather low.

Growth and Spread

As an indoor plant, Calathea Dottie has a moderate growth rate. It continuously grows in spring and summer, gets slower in fall, and might stop in winter.

This plant won’t take much of your space. The plant average size is around 12-25 inches, both in height and width. The big leaves create a bushy arrangement, so a 14 cm size pot is the best to accommodate Black Rose.

Light

Medium to bright indirect light works best for the leaf variegation and growth of Calathea Dottie. The plant must have an easy access to this kind of light for 6-8 hours every day.

Balancing the light

• Intense direct light like midday sunlight is going to scorch the leaves. The color may fade too under this condition.
• Black Rose is still tolerant to low lighting. However, in too less light and darker condition, wilting leaves, leaf discoloration, and slow growth may occur.

Light sources

• North or east-facing window provides morning and afternoon sun. While in case of west and south-facing window, the sunlight might be stronger. Thus, you can install frosted glass, sheer curtain, blind, or put the plant several feet away to avoid direct sunshine exposure.
• If you don’t have natural bright room, you can use artificial light. This would be pretty handful in cold months when the sun appears in a short time. There is also a suggestion to install 2 or 3 fluorescent lights in overhead position in indoor setting.

Location

Calathea Dottie plants can grow both indoor and outdoor. It will thrive well as long as you can provide an ideal condition and proper care.

Indoor

When planting them indoor, put the plant in a humid room with ample indirect lighting. Bathroom, kitchen, and bright living room are some available options. Avoid placing them in an area with sources of unstable temperature from inside and outside.

Outdoor

In a hardiness zone 10-11,growingCalathea outdoor could be an option. In this area, the climate would be more suitable for this plant.

Outdoor environment could be harsher and more unpredictable. Hence, you may consider making cold frame or growl tunnel to maintain the humidity, moisture, and temperature. Adding mulch on the plant keeps the soil cool and holds enough moisture.

If you live outside that area, make sure to bring the plant inside when the temperature drops (in winter).

Read also : Calathea Orbifolia : How to Successfully Grow

Temperature

In South America forest, Calatheas grow comfortably in warm temperature. It is the best to keep a stable temperature around 21°-26°C (70°-80°F). Trouble will arise if the temperature is lower than 18°C and higher than 35°C.

Actually, a normal house temperature is good enough for Calathea. Yet, unexpected temperature change can happen from inside and outside. If you put the plants near an open window or door, cold draft could hit them hard. Even inside the house, AC and fans might contribute to this shock.

Besides cold draft, Calatheas are also sensitive to heat as it would dry them out. Radiator, oven, and other heating systems could be more dangerous if the plants are close to this sources. Regarding temperature, this rule must also apply when watering the plants. In similar concept, hot and cold water may stress the plant.

Water

Calathea Dottie loves to stay in a moist soil, not too dry or too wet. Once you develop a good watering habit, it won’t be too hard to maintain it.

Check soil moisture

You can use finger testing or moisture meter. If your finger feels dry or the moisture level read barely dry, that is the time for watering. The top 2-3 inches of soil must before every watering takes place.

The common frequency is watering once a week or more in summer and less frequent in winter. Providing a little water but often is better than throw many at once according to the expert. Use water bottle or automatic plant waterer for easy watering.

Note. Checking soil moisture regularly would let you adjust the watering frequency according to the plant needs.

Ensure water quality

Calathea Dottie highly appreciates room temperature, free/low mineral water with pH between 5.5 and 6. You should also use this type of water for other plant treatments such as wiping and misting. Hard water contains high chemical, mineral, and salt content that would burn the foliage.

Distilled and rainwater are good for watering Calathea. If your city tap water is high in fluoride and chorine, rest them in a container for 24 hours before any usage. Another alternative is to buy concentrated treatment. People usually use this for beta fish tank water.

Note. NOT all tap water contains mineral. Some areas use well water as the source. Therefore, it is free from such chemical substances and safe for your Calathea.

Tips. It is better to water the soil than the leaves to avoid fungal related diseases. Then, wait the excess water to flow out of the pot drainage holes. Remember to also throw away the water left in tray or saucer.

Watering issue

Brown edges, yellowing curling leaves, and drooping leaves are the common signs of watering problem. Overwatering is more dangerous than under watering. If watering method is not the cause, water type, soil quality, and pot material could be the culprit.

Humidity

Human can be more sensitive to humidity than temperature. Cold temperature in winter or the use of heating source tend to create drier air. You might be okay, but your Calathea will protest. In some ways both of you must feel comfortable to live under the same roof.

A hygrometer will tell you the current humidity nearby. It is also useful to check the temperature.

Humidity range

• Below 40%  = lack of humidity causes brown, dried, and crispy edges
• 60%-80%      = ideal level is preferable
• Above 80% = too high humidity results in leaf spots

Raising and keeping humidity level

1.    Humid space

The options of humid space are glass cabinet, bathroom, kitchen, and laundry room. The next step is to check the lighting. High humidity is useless without good lighting for Calathea.

Tips. If your living area is likely to be more humid, you can put Calathea outside in spring and summer.

2.    Pebble tray

When filling the tray with water, stop before it soaks the pebble (or gravel, stone, etc.). Pebbles act as a boundary between the water and the root in the soil. You don’t want the plant experiences waterlog.

3.    Humidifier

Depend on the number of plants and area to cover, you may need more than one humidifier or at least one big size of it. Recently, there are various high quality humidifiers available on the market. Some have excellent features such as able to produce warm and cool mist as well as having high capacity.

4.    Gather other tropical plants

When putting the plants together, spare some space between the plants. A too close proximity will hamper air circulation and increase the risk of pest, bacteria, and fungal infection.

5.    Misting

Misting has become a subject of debate especially regarding its benefit to Calathea. In actual condition, misting only increase a little bit of moisture level in a short time. If the purpose is to prevent pest attack, misting can do this job well.

If you do this on daily basis, it helps you to get closer to the plant. Moreover, you might be able to spot any abnormality or other issues

Problem might occur when misting doesn’t follow the right steps. Below, there are some misting tips for your Calathea.

• Use spray bottle with the finest droplet holes and fill it with lukewarm water.
• Try misting the plant in the morning to let the leaves absorb the water faster.

Note. Among many methods above, many advanced gardeners say humidifier is the most effective solution with low risk.

Soil

Buy indoor houseplant potting soil as a starter. Then, add perlite and peat. These materials will allow smooth drainage and enough moisture retention. Another recommended materials are charcoal and orchid bark. Peat moss is common, but replacing with coco coir is better.

Soil pH

Ideal soil pH for Calathea Dottie is 6.0-6.5 (quite acidic). The acidity level of many commercial potting soil is usually close to the maximum range.

Use pH meter to find out the precise pH acidity. Soil pH could increase by adding one of the following materials:

• baking soda
• sprinkle of calcitic/dolomitic lime
• sulfur/aluminum sulfate
• wood ash

Potting

Calathea must grow in a medium-size pot with drainage holes. You can either drill to make holes or buy a new pot with drainage holes.

In choosing pot materials, plastic is the best to practice good watering habit. For you who tend to overwatering, terracotta is more suitable as it lets more water drain faster. On the other hand, clay pot could hold more moisture longer. So, use this pot if you often forget watering.

Considering self-watering pot

In particular, this pot has a reservoir, overflow, and separator. These features would prevent your plant from waterlogged. Refill when the water reaches the minimum level. It usually occurs after several days.

Read also : Calathea Medallion : Essential Guide for Growing The Plant

Fertilizer

Most Calatheas don’t need abundant fertilizer due to their average growth rate. Still, the plants need nutrients once the soil runs out of nutrients over time.

Time

During growing season (spring & summer), you need to feed them once a month. Reduce the fertilizer in the beginning of fall and never feed them in winter. In this period, the plants are going to take a rest and fertilizer might kill them.

Dosage

Always water the plant first before feeding Calathea. The common suggestion is to dilute water-soluble fertilizer at half dosage. Both synthetic and organic fertilizer have their own advantages and disadvantages. The key is to avoid over fertilizing.

Fertilizer burn

It may occur due to over dosage, feeding in winter, and the use of inorganic fertilizer. The unused fertilizer contains salts that build up in the soil. They probably show up on the soil surface as white powder-like substance.

If you spot burn marks, reduce the fertilizer by half again from the previous dosage. Brown spots and yellow edges are common in Calathea. However, it is dangerous once they spread to the whole plant.

Thankfully, there is a simple remedy for it.

• Put the plant under a water faucet or shower.
• Leave the plant for 5-10 minutes so that the water could flush away the fertilizer waste.
• Wait after the excess water drains.
• After that, don’t feed the plant till it recovers.

Tips. Gardeners often use compost and fish emulsion as a fertilizer. After all, try to use organic product as possible.

Note. In high light level condition, reduce the feeding frequency into once every two/three months.

Maintenance

Trimming

Calathea Dottie will spend extra energy to heal dying leaves. For this reason, you should cut the dead leaves and stems. With this, the plant can focus on the new and healthy foliage. Meanwhile, others just trim the leaves to get a better shape plant.

• Prune the brown or yellow leaves with sterile shears. Wipe the shears with rubbing alcohol first to avoid any contamination. Clean cut promotes faster recovery.
• For a completely damaged/dead leaves, it is okay to pull/cut them along with the stems.
• If there is only a small damaged area on the leaves such as crispy edges, don’t remove them at once. Instead, only trim the affected part. It is to reduce further damage and give a chance for the leaves to heal.

Cleaning

Foliage shape and appearance could change dramatically because of various factor. Leaf cleaning time is a perfect moment to check the plant health too. Cleaning aims to encourage better respiration and block pest infestation.

• Wipe the leaves with damp cloth/rag/soft towel to remove the dust and debris. Mixing water and neem oil for leaf washing is also good, especially to keep the pests away from your Calathea.
• Another method is to run water shower on the plant. Remember to only use room temperature at a considerable force/strength.

Repotting

In average, you can repot Calathea Dottie every 2 or 3 years. This is a good news since Calathea hates any kind of disturbance, particularly on the roots. Frequent repotting would shock the plant, so do this very occasionally. Repotting in early spring provides more time for the plant to recover.

Reason to repot

When the roots have expanded outside the pot and soil surface, you should repot them for better growth. In case of pest and disease issue, you might have to repot the plant immediately.

Tips for repotting

Pot. Since the current pot has become too small for Calathea, upgrade the size by 1-2 inches wider. Additionally, oversize pot has higher risk of overwatering. Plastic pot with drainage holes would be perfect.

Soil. Fill the pot with new fresh soil, preferably with the same composition as the old pot soil.

During the process, treat the plant carefully and try not to upset the sensitive roots.

Propagation

Propagation of Calatheas is possible through division method once they mature.

1. Take the mother plant from the pot gently after watering it a day before.
2. Inspect the natural division. It will look like 2 plants grow, each with leaves and roots.
3. Separate the section using finger. For untangled roots, cut them with disinfected scissors or pruners.
4. Similar with repotting, let each section grows in new soil but with same quality as before.
5. Never shock them by adding fertilizer, overwatering, and the like.
6. Two or four weeks later, the plants should have established their root and start produce new growth.

Note. Since Calathea considers propagating and repotting as a drastic change, only do these in growing months especially early spring.

Common Problems

Black Rose is NOT the most vulnerable plant from pest and disease in the world. Sadly, incorrect care and maintenance as well as nature factors might weaken the plant. As a result, pest and disease could easily attack this greenery.

Handling pests

Common pests of Calathea are: aphids, fungus gnats, mealybugs, scale, spider mites, thrips, and white flies. They basically suck the plant sap and leave ugly marks on the leaves while building their “kingdom”. Some pests are very active and they could easily jump and flies to find more preys.

Prevention

• Thorough check. Before the plant gets hurt, make sure you examine all parts including the undersides and stems. It is easier to do this when you water the plant. You might need magnifying glass to spot their tiny size.
• Proper cleaning. Flushing, wiping, and showering could prevent the pest. During this process, you might get rid of them accidentally, which is a good thing.
• Control humidity. Both too low and too high humidity can invite the pests.

Troubleshooting

1. Isolate the plants from others to avoid further spreading.
2. Give a quite strong shower to the plant and use plastic to cover the soil. Throw the plastic away which contains the fallen pests and their eggs after showering.
3. You will need damp cloth for wiping the infected leaves. Using a cotton ball after applying rubbing alcohol on it, is effective for pest like mealybugs. For heavily damaged leaves, trim and throw them.
4. Spray the plant with horticultural oil, insecticidal soap, or neem oil in regular basis till the pests gone forever. If the only option is to use chemical pesticide, choose non-hazardous which is safer for plant and human. Repeat this action to eliminate the entire pest colony.

Common Disease

• Brown/black spot. Cause: overwatering.
• Burnt/crispy leaves. Cause: excessive sunlight, chlorine and mineral-rich water, and over-fertilizing.
• Droopy leaves. Cause: Low humidity and improper lighting.
• Yellow leaves. Cause: nutrient deficiency, over fertilization, overwatering, pests, root stress, temperature and humidity changes, under watering, wrong lighting, etc.

General solution:

• Remove the damaged leaves.
• Always go with medium-bright indirect light setting.
• Watering and flushing using soft water.
• Let excess water flows freely through drainage holes.
• Utilize humidifier to control ideal humidity.

Note. In the worst case, root rot could happen. After quarantine the plants, cut the unhealthy plant parts (dark and mushy roots, stems, and leaves). Then, repot only the healthy part (we hope you still find it).

Buying Calathea Dottie

Use Calathea name when you are looking for this plant. Despite the fact that Goeppertia is the current botanical name, most people is more familiar with Calathea.

You can find them in local nursery or online stores. The price range is $15 to $30 depend on the size. Always choose a healthy plant without the sign of disease and pest.