Camellias are generally pretty happy, healthy plants, offering beautiful blooms at the start of spring to really herald the arrival of fresh growth, all held against a verdant backdrop of glossy, evergreen foliage that really pushes the flowers to the fore.

Even the happiest, healthiest plants can still experience the odd problem from time to time, however, and camellias are no exception. In this post, we’ll unpack some of the issues you might come across when growing camellias. Don’t let this put you off, though. Think of it more as a backup failsafe to have to hand, just in case.

Jump to:

• Root rot
• Flower blight
• Aphids/scale insects
• Canker
• Leaf gall
• Weak growth
• Poor flowering

What are the most common problems with camellias?

Root rot

Signs

The main symptoms of root rot include stunted growth, browning/yellowing foliage and the disintegration of the roots into a mushy mess. Not nice.

Cause and cure

Root rot typically stems from overwatering or poor soil drainage. If you catch it early enough, then you can still save the plant from being totally lost. Let the plant dry out, then lift the plant from its planting hole/container, sterilise some shears and prune out the affected area. Ensure drainage is improved if you’re going to return it to the same spot (or use some freer-draining compost in the case of potted camellias).

Camellia flower blight

Signs

Camellias affected by flower blight are recognisable by the brown flecks that appear on the petals, which promptly grow in size until the entire petal is covered with a brown stain. The flowers affected often fall from the plant earlier in the season, too.

Cause and cure

A result of the fungus Ciborinia camelliae, first seen in Japan over a century ago, camellia flower blight can ruin a camellia’s blooms, but with a few tips, you can significantly reduce the likelihood of being affected by it. Remove spent flowers that have fallen to the floor, as this is where the sclerotia of the fungus develops, from which the rest of the lifecycle can then progress. Applying a deep layer of mulch around the plant’s base, meanwhile, helps bury any apothecia (the spore-producing structures of the fungus) and can thus help prevent fungal spores from rising on air currents and infecting the flowers.

Aphids/scale insects

Signs

Scale insects are detectable as small, unmoving bumps that blister the plant’s leaves. Aphids, meanwhile, secrete a sticky honeydew and are visible as tiny black or green bugs. Both can lead to stunted growth and the development of sooty moulds (caused by their sap-sucking tendencies).

Cause and cure

Aphids and scale insects can be tolerated in small numbers without too much hassle. Should they multiply to the point of infestation, however, then you’ll need to take action to cement the future health of your camellia. Squish them with your finger or spray the affected area(s) with soapy water and wipe the foliage down.

Canker

Signs

Canker presents itself through yellowing leaves, suddenly wilted branches and dieback, and is most commonly seen in hot, humid conditions.

Cause and cure

A result of the fungus, Glomerella cingulata, which accesses camellia plants through wounds. It can be mitigated against by pruning with sterilised shears and doing so in dry conditions, while the affected areas can be pruned out before the rest of the plant is affected.

Leaf gall

Signs

Camellia leaf gall is easy to identify; the leaves thicken and solidify, become pale green in colour and develop the texture of citrus peel. Eventually, the whole leaf will turn brown and develop that hard, shell-like feel.

Cause and cure

Another fungus-derived disease, camellia leaf gall is caused by Exobasidium camillae and typically affects sasanqua camellias more than Japanese camellias. Treatment is straightforward, just remove the affected foliage and remove as part of your garden waste. You don’t want to let the infection spread so avoid composting the leaves that have been infected.

Other issues affecting camellias

Weak growth

Your camellia may not be affected by any of the above, and yet you still might be worried about it – your next door neighbour, Jim, has a camellia going great guns and yours is, well, not. But why? Nine times out of ten, poor camellia growth comes as a result of the soil being inappropriate.

Alongside rhododendrons and azaleas, camellias will only truly flourish in acidic soils. If your soil is neutral or alkaline, you’ll get poor to middling results, at best. The easiest way around this is to grow your camellia in a large container in ericaceous compost, or if you’re determined to have one in the open ground, then amending the soil in the planting area with something like sulphur is your best bet.

Poor flowering

Poor flowering can occur due to a couple of factors; firstly, if you’ve been a bit snip happy with the ol’ pruning, then you could well have accidentally cut off the flower buds – it sounds silly, but it’s easier than you’d think to accidentally trim them off. Another major culprit is over-fertilising, especially during the growing season, as this promotes the growth of new foliage over flowers.

Final thoughts

With this guide at your side, you’re now better equipped to deal with any problems your camellia(s) might run into. As we said at the start, this is a worst-case kind of document, but you know how the saying goes – forewarned is forearmed! While you’re here, make sure to check out our guide to camellia growing for more top tips.