Dear Sibe,

I have a marguerite bush which is planted in a large container and it is starting to yellow. What could be causing this? Also, when de-heading it, where do I cut from? As you can probably tell I am a novice gardener!

Many thanks,

Trina

Our Gardening Expert replies::

Hi Trina,

The name 'marguerite' is commonly used for a number of plants with daisy-like flowers, but usually for types of Argyranthemum frutescens or Chrysanthemum leucanthemum. Both these used to be known as chrysanthemums and are perennial plants, but as they are not hardy, they are often treated as summer annuals. Planting in a large container is fine and these do best in well-drained compost in a sunny position - the sunnier the better!

Your plants may be starting to have yellow leaves because the compost is exhausted. This is typical of peat-based composts which, though may be more pleasant to use and lighter to carry around, don't contain a reservoir of plant food which can keep the plant growing throughout the year. If you use this type of loam-free compost you need to add slow release fertilizer or to regularly liquid feed after about a month.

You can try spraying your plant with a dilute liquid feed (diluted to, say, one quarter of the normal strength). When sprayed over the leaves some of this plant food will be absorbed directly and will help to green up the plant again. At the same time, liquid feed at normal strength. You can also try seaweed fertilizers as these have a good reputation as foliar feeds. When planting next year be sure to use new compost!