How to grow codiaeum

What are crotons?

Known as crotons or codiaeums (or botanically as Codiaeum variegatum), these are bold and colourful evergreen shrubs, native

A native plant is one that originated or arrived naturally in a particular place without human involvement. In the British Isles, native plants are those that were here during the last ice age or have arrived unaided since.

to tropical regions of Malaysia, Indonesia and Australia. When grown as houseplants, they need consistently warm temperatures, indirect light, regular watering and high air humidity

The concentration of water vapour in the atmosphere. This affects the rate at which plants transpire (lose water from their leaf pores), which in turn affects how much water their roots absorb from the soil. If air humidity is low, plants transpire quickly and become at risk of wilting if water is lost from the leaves faster than it can be absorbed by the roots. Different plants require different levels of humidity to thrive. Many tropical houseplants need high humidity and are best grown in a steamy bathroom, misted regularly or placed on a saucer of damp pebbles. In a greenhouse, humidity can be raised in hot weather by damping down (wetting) the floor or overhead misting.

.

Several cultivars are available, offering different leaf shapes, textures and colour variegations, including white, purple, orange, yellow, red and pink. The colours often form contrasting splashes or blotches or follow the veins of the leaves. Plants range from a compact 30cm (1ft) tall, up to 90cm (3ft) or more, depending on the cultivar

Gardeners often use the word variety when referring to a specific plant, but the correct botanical term is 'cultivar'. Whichever word you use, it means a distinctive plant or plants, given a specific cultivar name and usually bred to enhance certain characteristics, such as flower or fruit size, colour, flavour or fragrance, plant size, hardiness, disease resistance, etc. Additionally, it is worth knowing that, botanically, variety has another meaning - it refers to a naturally-occurring distinct plant that only has slight differences in its looks. For example, Malva alcea var. fastigiata differs from typical plants by having an upright habit.

and age.

Wear gloves when handling codiaeums, as the white latex-like sap

Sap is a fluid that circulates through a plant's vascular system, in a similar way to blood moving through our veins. Phloem sap carries the sugars produced in the leaves by photosynthesis down to roots and other storage organs, as well as carrying minerals and hormones. Xylem sap is watery and transports nutrients absorbed by the roots upwards to the rest of the plant. Some plants leak sap from wounds or pruning cuts, and this is known as bleeding.

is a skin/eye irritant, and all parts of the plant are poisonous, so always keep them safely away from children and pets.

Buying crotons

It’s usually best to buy plants in person, rather than online, so you can choose the leaf shape and colouring you prefer. These flamboyant plants are available from many houseplant retailers, with larger stockists offering the widest range of cultivars.

Choose a healthy-looking plant with lots of vibrant leaves and no signs of wilting or damage. As codiaeums are tropical plants, be sure to keep them warm while bringing them home.

Buying: garden centre plants

Buying: mail order plants

Crotons can usually be kept in their original pot for a year or two. Once the roots become crowded, repot in spring into a slightly larger container. Be careful not to choose a pot that is much bigger than the rootball

The roots and accompanying soil when a plant is removed from a container or lifted from the ground.

(overpotting), as this will risk the compost

Can refer to either home-made garden compost or seed/potting compost:

• Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own.

staying too wet for too long, leading to root rot.

Use a peat-free ericaceous (acidic) compost that is light, fast draining and loam free, such as a mix of three parts peat-free ericaceous

Plants that thrive in acid or ericaceous soil, which has a pH of less than 7 (neutral). You can measure your soil pH using a simple testing kit. Ericaceous or acid-loving plants include rhododendrons, camellias, heathers and blueberries.

compost to one part grit.

Continue repotting every few years, as soon as the roots fill the container.

See our guides on repotting houseplants:

How to repot a plant

Peat-free compost choices

Location

Crotons need bright but indirect light in summer to grow well. In insufficient light, the leaves may lose their vibrant colours or drop, but if exposed to full summer sun through glass, they may overheat and scorch. The plants will grow less in winter, when light levels are lower.

Temperature

As codiaeums originate in tropical regions, they need constant warmth throughout the year, around 18–35°C (65–95°F). Make sure they don’t go below 15°C (55°F). Fluctuating temperatures and cold draughts can cause the leaves to drop.

The concentration of water vapour in the atmosphere. This affects the rate at which plants transpire (lose water from their leaf pores), which in turn affects how much water their roots absorb from the soil. If air humidity is low, plants transpire quickly and become at risk of wilting if water is lost from the leaves faster than it can be absorbed by the roots. Different plants require different levels of humidity to thrive. Many tropical houseplants need high humidity and are best grown in a steamy bathroom, misted regularly or placed on a saucer of damp pebbles. In a greenhouse, humidity can be raised in hot weather by damping down (wetting) the floor or overhead misting.

These tropical plants like moist air, so stand the pot over a tray of damp pebbles or ceramic clay granules – the water will slowly evaporate, raising the humidity around the foliage.

Wipe the leaves with a damp cloth occasionally too, to remove dust and help the plant absorb sunlight efficiently.

Watering

Water once the top layer of compost

Can refer to either home-made garden compost or seed/potting compost:

• Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own.

has dried out, preferably using rainwater at room temperature. Too much water can lead to root rot, so hold off watering if the compost is still damp to the touch and tip any excess away afterwards, so plants aren’t left standing in water for long periods.

Avoid using hard tap water on a regular basis, as this makes the compost more alkaline, instead of maintaining the acidic conditions that codiaeums enjoy. Use collected rainwater or softened water whenever possible.

Reduce watering in winter, when growth slows down – always let the compost be your guide, only watering when the surface feels dry.

Collecting, storing and reusing water

Houseplants: holiday care

If your plant becomes mis-shapen or leggy (tall and straggly), prune in spring to make it more compact and encourage leafy side-shoots. Make your cut above a leaf joint, and use sharp secateurs.

When pruning codiaeums, always wear gloves and take care not to let the irritant milky sap

Sap is a fluid that circulates through a plant's vascular system, in a similar way to blood moving through our veins. Phloem sap carries the sugars produced in the leaves by photosynthesis down to roots and other storage organs, as well as carrying minerals and hormones. Xylem sap is watery and transports nutrients absorbed by the roots upwards to the rest of the plant. Some plants leak sap from wounds or pruning cuts, and this is known as bleeding.

get onto your skin or in your eyes.

To make new plants, take softwood cuttings in early summer.

Codiaeums can be tricky to keep in good condition, as they need high humidity

The concentration of water vapour in the atmosphere. This affects the rate at which plants transpire (lose water from their leaf pores), which in turn affects how much water their roots absorb from the soil. If air humidity is low, plants transpire quickly and become at risk of wilting if water is lost from the leaves faster than it can be absorbed by the roots. Different plants require different levels of humidity to thrive. Many tropical houseplants need high humidity and are best grown in a steamy bathroom, misted regularly or placed on a saucer of damp pebbles. In a greenhouse, humidity can be raised in hot weather by damping down (wetting) the floor or overhead misting.

and constant warmth. The main issues you may find are:

• Leaf drop – if your plant is losing a lot of leaves, it may be because the compost
  

  Can refer to either home-made garden compost or seed/potting compost:

  
  • Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own.

  is too dry, or the air is too dry, the plant is in a cold draught or the temperature is below 15°C (55°F) for a long period
• Root rot – is caused by waterlogged
  

  Describes soil or potting compost that is saturated with water. The water displaces air from the spaces between soil particles and plant roots can literally drown, unless they are adapted to growing in waterlogged conditions. Waterlogging is common on poorly drained soil or when heavy soil is compacted.

  compost, due to overwatering, leaving the pot standing in water, or using poorly draining compost (add grit to improve drainage when repotting). Left unchecked, this can kill the plant
  

How to help a poorly houseplant

Leaf damage on houseplants

Mealybug