Even the most experienced gardener can come across camellia problems. But most can be remedied if you've got the know-how.
These glossy evergreens are valuable stalwarts for flower beds and pots, not least for their beautiful winter blooms. On the whole, camellia care isn't too tricky – pruning isn't strictly necessary and, as long as they're planted in the right place, they tend to do well.
However, there are a few things to look out for, such as pest damage, yellowing leaves, and a lack of blooms. Our guide explains the key camellia problems you may come across, so you can identify and treat them quickly should they appear, as well as prevent them from happening to begin with.
5 common camellia problems to look out for
Keep your winter-flowering shrub looking tip-top with this advice.
1. Pest damage to camellia leaves and buds
Pests can cause damage to all types of plants, camellias being no exception.
If you've noticed your shrub shedding its leaves, vine weevils may be to blame. As John Negus, a gardening expert from Amateur Gardening explains, the larvae of these creatures devour roots. Meanwhile, the adults bite semi-circular chunks from leaf edges.
You'll need to examine the roots. 'If you discover 1⁄4in (6mm)-long dirty-white grubs with orange heads, then vine weevil is the cause of your camellia’s plight,' he says. Overcome it by using a vine weevil killer, available on Amazon (opens in new tab). 'When grubs have died, your plant will make fresh roots. Ideally, in spring, repot it in loam-based ericaceous compost.'
Vine weevils aren't the only intruder to look out for. If you've spotted black, sooty markings on the leaves of your camellia, then scale insects or aphids are probably the cause. These feed on sap and can seriously debilitate growth and vigor, says John. The substance, known as honeydew, that they excrete is what attracts the sooty mold.
If the problem is only seen in small areas, you can try wiping it off. Otherwise, try spraying the plant with an insecticide such as Bugclear Ultra (opens in new tab) or Provado Ultimate Bug Killer (opens in new tab), both available on Amazon, as John recommends. 'Once they have gone, the sooty mold will stop being produced. You can wipe it off with a damp, soft cloth.
'Ultimately, if you control insect pests intent on colonizing your camellia, old infected leaves will drop and pristine new foliage will replace them,' John adds.
Deer can also cause camellia problems. If you've noticed flower buds disappearing overnight, they may have been grazed on by these interlopers. You can spray the bushes with dedicated deterrent formulas. If they're truly proving to be a pain, it might be worth swapping out your shrubs for deer-resistant plants, instead.
2. Yellow leaves from nutrient deficiency
'For plants to thrive, they need to be in the correct place, so things to consider are always soil type (i.e. are they planted in the right soil type for the plant's preference); exposure (does the plant need a sheltered location or not?); and light (does it have too much or too little?)' says Jamie Shipley of Hedges Direct (opens in new tab).
If your camellia's leaves are turning yellow, chances are it is suffering from nutrient deficiency, often made worse by the wrong type of soil. 'They need a slightly acidic soil – in soil with the wrong pH, the leaves tend to be small and yellow between the veins,' says John. This is known as lime-induced chlorosis.
Fertilizing plants will give them a boost and help restore shrubs to good health. The best time to feed camellias is in mid-spring, John suggests, as the plant is coming back into growth after a winter dormant period. 'It will also help to support the plant after flowering.
'Apply a balanced fertilizer, or one designed for trees and shrubs, before mulching,' John continues. It might be worth giving a second application in early summer if the plant is struggling, he adds, but don’t feed after the end of mid-summer.
Note that watering plants can impact the soil's pH. 'If you live in an area with hard water, your tap water may contain too much calcium and this will reduce the acidity of camellias’ preferred soil and compost over a period of time,' John adds. Collect rainwater instead, though tap water is fine to use just for a month or two over the summer.
Also, bear in mind that pruning camellias – especially when reducing branches towards the bottom – can reveal more soil which makes it easier to fertilize and mulch the plants.
As well as the pH and fertility of the soil around your camellia, there are other environmental factors to take on board.
For one, the soil should be kept moist throughout the year. Camellias cannot tolerate drought or waterlogged conditions. If your soil tends to dry out, a mulch of bulky organic matter in early spring over the whole root zone (which probably extends as wide as the branch system) will be beneficial, says John. Avoid it coming into contact with the stems. If the soil is waterlogged, move the shrubs into an area with better drainage, adding plenty of grit around the root system.
These shrubs also need a sheltered spot with protection from windy conditions and do best in dappled or full shade.
3. Failing blooms due to cold temperatures
Have you noticed the buds on your camellia turning brown before they bloom? Low nighttime temperatures are the probable cause.
If this has already happened to your shrub, all you can do is remove the damaged buds and feed the plants with 1oz (28g) per square meter of sulfate of potash, says the Amateur Gardening experts. Apply it monthly from mid-spring until early fall. 'Water it in if the soil is dry. It will toughen tissue and help to make your shrub more resilient to frosty nights,' they explain.
In the future, protect plants from frost by draping the bushes with several layers of fleece when a clear evening sky heralds a sharp drop in temperatures later on, they continue. 'Remove it the following morning when it’s warmer. Ideally, camellias should not be planted facing east, where early morning sunshine on frosted flower buds may cause cells to rupture and die.'
White-flowering types of camellias are less hardy than red and pink types and therefore more susceptible to frost damage.
Young foliage can also be affected by frost and turn brown as a result. There is no treatment, so simply remove unsightly areas, says the RHS (opens in new tab).
4. Camellias not flowering due to a lack of water
If your camellia hasn't succumbed to frost damage but the buds still aren't opening as expected, a lack of water could be to blame.
'If they are starting to fall or do not look fat and healthy, this may be a result of the soil being too dry when the flower buds were being set,' says John. 'This tends to happen in late summer and early autumn, and just a few days of dry weather can result in reduced flowering.'
So, be sure to water the plants thoroughly and regularly throughout late summer and early fall – our tips on watering plants while away will come in handy if you're planning a vacation.
5. White growths caused by camellia gall
Camellia gall is a common fungal disease that results in large, white, unsightly growths on leaves that appear in early summer.
As the RHS says, they can look rather alarming – after all, these galls can be up to 6in in length. However, they're not a cause for serious concern as they won't damage the plant long term. Cut them off and destroy them as soon as possible. If spores have appeared, they suggest enclosing the gall in a plastic bag first.
The garden was always a big part of Holly's life growing up, as was the surrounding New Forest where she lived. Her appreciation for the great outdoors has only grown since then. She's been an allotment keeper, a professional gardener, and a botanical illustrator – plants are her passion.
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