Thompson & Morgan Facebook Q&A Session 14th June 2013 - Your horticultural questions answered.

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Name: Andy Lyttle

Question: I bought Sundaville Red last year and the two plants have grown well in a (heated) conservatory with plenty of foliage. Unfortunately, there is, so far no flowers. I have been feeding the plants over the last six weeks. Any suggestions to a cause or cure please. Andy

Answer: Hi Andy, in our climate, Mandevilla can bloom quite late in the summer so I wouldn’t be too concerned just yet. They flower on the current year’s growth and periods of cold or dull weather will slow them down. They are tropical plants, adapted to the high temperatures and humidity in South America. Provided temperatures are warm, preferably around 21°C (70°F) during the day with a minimum of 15°C (59°F) at night they should be happy enough to flower. Just make sure they are in full light all day and try increasing humidity by standing the pot in a tray of gravel with a little water in (make sure the pot is raised above the water level). I hope this helps and your Mandevillas bloom soon.

Name: Iona Wilson

Question: We have inherited 2 old apple trees and have begun the restoration of them to let them be loved again (following the suggested thinning and pruning etc) but they have been attacked by aphids on an epic scale over the last few days and all the leaves are curling. The aphids have now spread to our very young apple trees.... HELP ... what can we do?

Answer: Hi Iona, don’t worry - it will be possible to bring this back under control and there are measures you can take to prevent this happening next year. As the aphids have caused the leaves to curl and are probably hidden inside, organic contact insecticides are unlikely to be effective. The best course of action would be to use systemic insecticides (enters the plant’s vascular system) which are approved for use on fruit trees. You could try insecticides containing thiacloprid (Bayer Provado Ultimate Bug Killer) or acetamiprid (Scotts Bug Clear Ultra) - these active ingredients are normally written on the label.

This winter, use an oil winter wash such as Growing Success Winter Tree Wash to remove overwintering aphid eggs. This winter treatment is likely to be most effective at reducing the problem for next year but you will need to be vigilant in spring for a recurrence of the aphid which will need spraying. If the problem recurs next spring you could try using an organic spray such as Bayer Organic Pest Control. This has quite a short persistence and works on contact so you will need to be thorough and may have to spray several times throughout the season. However, this spray can be used right up to a day before harvesting which is a great benefit. I hope this helps, good luck.