Agapanthus are thriving

Yellow sticky traps to catch whitefly (S)
Yellow sticky traps to catch whitefly (S)

Martin Fish, Director of Harrogate Flower Shows this week advises on agapanthus.

One plant that has become very popular over recent years is agapanthus and they are now widely available. In the past they have always been regarded as tender, but they are surprisingly tough considering they originate from South Africa. Over the years many new strains have been developed that are much more suited to our climate and one of the top agapanthus specialist nurseries in the UK is based in Yorkshire. As part of their growing programme they are actively breeding new cultivars of agapanthus that are hardy and so far they have come up with some lovely new introductions that are always on show at the Harrogate Flower Shows.

When growing agapanthus in the garden you have the choice of growing in containers or the border.

When growing in the border, the soil needs to be fairly well drained and the plants need a sunny position. I prefer to plant in early summer in order to give the plants plenty of time to settle in before winter.

In containers use a loam based compost, again with good drainage and stand the pots in a sunny spot. The advantage of growing in large pots is you can bring the plants under cover in very frosty weather should you need to.

Grown outside agapanthus flower at this time of the year and through until early autumn. To keep the plants healthy and growing it is important to make sure that the plants are watered in dry weather. Although they come from Africa, they can be thirsty and will need regular watering. Feeding is also important especially from now onwards and the recommended feed is high potash such as Phostrogen or tomato fertiliser. This will keep the plants flowering through the summer, but more importantly, the potash content induces winter hardiness, meaning the plant will be much better prepared should we get a cold winter.

Readers’ Questions

Janice from Boroughbridge is growing tomatoes in her greenhouse that are doing really well, but she has just noticed a few white flies and wants to know how best to deal with them without spraying chemicals.

White fly can be a serious pest on tomato plants. What starts as just a few small white flying insects very quickly can develop into a heavy infestation. Although you don’t want to spray, there are some organic pesticide sprays available that are based on natural products that you might consider, but always read the label before use. A totally spray-free method is to use the yellow sticky traps suspended between the plants which are very effective.

Jobs for the week

Harvest courgettes little and often as in warm weather the fruits grow very quickly and turn into marrows.

Continue to deadhead annuals and bedding plants to encourage more flowers and keep container grown plants well watered.

There is still time to lift and divide crowded clumps of bearded iris. After dividing, trim the leaves back by half and plant so that the rhizome is visible on the soil surface.

Read more:

Beware changes in the weather

It’s been a good year for roses