Codonanthe diseases, pests & problems

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Bell-shaped flowers dangle from trailing stems whose leaves and fruits carry tiny velvety hairs that help fend off pests such as thrips. This Gesneriaceae relative of African violets is a suspension houseplant that rarely causes trouble, provided the soil dries out between waterings — yellow, flimsy leaves are the warning of impending root rot.

The most common (though still hard to find) Codonanthe species are C. crassifolia and C. deviosana (which has 2 famous cultivars: ‘Pink’ and ‘Paula’. Similar problems affect both of these species.

→ Similar problems, similar solutions: issues with hanging Stephanotis

Codonanthe symptoms at a glance

Bell-shaped flowers dangle from trailing stems whose leaves and fruits carry tiny velvety hairs that help fend off pests such as thrips. Codonanthe, a Gesneriaceae relative of African violets, is a trailing suspension houseplant that rarely has problems — provided the soil dries out between waterings, since yellow, flimsy leaves warn of root rot.

Whichever line matches your plant, the detailed section that follows gives the full course of action.

Dry edges on Codonanthe plant

This is a case of “dry air”. The stem can’t pump water to the leaves fast enough to counter transpiration in dry air.

• Mist the plant often with a hand spray
• Try to grow other plants nearby to create a “air moisture oasis”.
• Set a mini-fountain in the vicinity.
• Another way is to simply a put the pot atop a tray with wet clay pebbles. Water will evaporate, raising air moisture.

• When standing a Codonanthe on a tray of clay pebbles, keep the water level below the base of the pot, so the compost is not kept waterlogged while the surrounding air stays humid.
• Hang the Codonanthe well away from radiators, heating vents, air-conditioning outlets and draughty doorways, as the moving dry air there strips moisture from the trailing leaves faster than the stems can replace it.

Codonanthe turning yellow and flimsy

This is the sign of impending root rot. Stop watering immediately and wait for the clump to dry up almost entirely.

• When soil feels dusty right to the center, water again but only a small amount.
• Make sure you let the soil dry up before watering every time.

You can also take a drastic course and rinse everything out: soil, rotten root parts, etc. Let it dry out for at least two days and then repot in fresh soil or orchid mix.

• Empty the saucer or decorative cachepot a few minutes after watering the Codonanthe, because roots left standing in water suffocate and rot far faster than roots in merely damp soil.
• If you rinse the roots bare, trim away brown, mushy roots back to firm pale tissue with clean secateurs, since badly decayed tissue is unlikely to recover and can carry rot into the fresh mix.
• Repot the Codonanthe into a container barely wider than its root ball, since this epiphyte’s sparse roots cannot draw on the large mass of damp soil an oversized pot holds, which risks waterlogging.
• Withhold fertiliser from a Codonanthe recovering from root rot until fresh leaves and stems appear, as fertiliser salts burn a root system that is already damaged and unable to take them up.

Common pests on Codonanthe

• White sticky blobs at leaf joints – mealybugs, a particular type of scale insect
• Sticky glossy substance on leaves, leaves curling up – aphids, which are relatively easy to deal with
• Leaves seem dusty and start turning yellow – red spider mite is what you’re up against

Leaves and fruits have tiny velvety hairs all about that help it fend off other pests, for example thrips.

• Dab the white blobs at the leaf joints of a Codonanthe with a cotton bud dipped in rubbing alcohol, then check again a week later, as sheltered eggs hatch in successive waves.
• Red spider mites favour hot, dry conditions, so sustained high humidity around Codonanthe discourages them, but brief misting lifts humidity only transiently and should be treated as a minor aid rather than reliable control.
• Lift and turn the trailing stems of a hanging Codonanthe to inspect leaf undersides and the base of the small berries, where mealybugs and mites settle out of sight.
• Rinse honeydew off Codonanthe foliage with lukewarm water, because the sticky film left by aphids turns black with sooty mould and blocks light from reaching the leaves.

Codonanthe leaves forming drops at the tip

Occasionally, especially the plant is watered at night, drops of fluid will appear along the edges of Codonanthe leaves.

• This is a perfectly harmless process called “guttation“.
• It is how the plant expels excess water during the night when roots are too wet.
• In the case of this ant-attracting plant, this phenomenon doubles as a “food source” for ants.
• If it happens repeatedly, try watering in the mornings instead.

→ Read also: how to care for Codonanthe

• Guttation drops on Codonanthe are clear and watery, but sticky, glossy fluid is not proof of pests: Codonanthe bears extrafloral nectaries that secrete sugary, ant-attracting droplets, so inspect for aphids or mealybugs before concluding honeydew.
• The droplets on Codonanthe leaves are typically sugary extrafloral nectar rather than mineral-bearing guttation fluid, so they dry into sticky shiny spots that may attract ants or sooty mold; wipe the foliage with a soft damp cloth.

Frequently Asked Questions

Why is my Codonanthe turning yellow and going limp?

Yellow, flimsy foliage is the sign of impending root rot. Stop watering at once and wait until the clump has dried up almost entirely, then water again with only a small amount once the soil feels dusty right to the centre. In severe cases you can rinse everything out — soil and rotten root parts — let the plant dry for at least two days, then repot in fresh soil or orchid mix.

How do I stop my Codonanthe leaves drying out at the edges?

Dry edges mean the air is too dry: the stem cannot pump water up to the leaves fast enough to keep up with transpiration. Mist the plant often with a hand spray and grow other plants nearby to create an “air moisture oasis”. A mini-fountain in the vicinity, or standing the pot on a tray of wet clay pebbles so the water evaporates, will also raise air moisture.

Which Codonanthe species are usually grown indoors?

The most common species, though still hard to find, are Codonanthe crassifolia and Codonanthe deviosana. The latter has two well-known cultivars, ‘Pink’ and ‘Paula’. Both species are affected by similar problems, so the same solutions apply to either one.

Why does my Codonanthe form drops of water at the leaf tips?

This is a perfectly harmless process called guttation, and it happens especially when the plant has been watered at night. It is how the plant expels excess water during the night when the roots are too wet, and in this ant-attracting plant the drops double as a food source for ants. If it keeps happening, switch to watering in the mornings instead.