Plant Doctor Archive

Camellia troubles

I HAVE a problem (among many!) with some camellias. They are suddenly becoming covered with brown leaves. They have been in my garden for just over a year and not grown very much but have borne plenty of flowers. Having looked in a book we have on plant problems, it would seem that the plants are lacking fertiliser, so I fed them yesterday.

However, on the bag of fertiliser, it says to be used in spring or autumn. It doesn't actually say one dose but that's how I read it. They really are bad and I wonder if a second application would be OK and would not cause any further damage. I also wondered if a dose of Epsom salts would help.

WITHOUT examining your plants, it's hard to say exactly what is causing the problem, but as they've only been in the ground a year, I think it's more likely to be a root problem than lack of nutrients in the soil.

Root damage often doesn't show until spring or early summer when the upper parts of the plant start into growth. If the damaged root system can't supply the leaf growth demand, a variety of deficiency symptoms can occur, including yellowing and browning of the foliage.

The damage to the roots of your plants may have occurred as long ago as last autumn during a drought, or over winter when the soil was very wet.

Don't give them any more fertiliser until at least autumn, by which time you'll know how well they are recovering.

Also, do whatever you can to keep the soil moist over summer - mulch the soil surface and water regularly.

It's also worth remembering that camellias grow best in relatively acidic soil, so avoid using lime anywhere near them. Lime prevents acid-loving plants from being able to draw some nutrients from the soil which can cause leaf yellowing and, in extreme cases, browning. Newly laid concrete drives or paths can also release lime into the soil nearby and have a similar effect on acid-loving plants.

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.