On 16/04/2017 10:56, Bertie Doe wrote:
A 5 year old bougainvillea is suffering rapid leaf loss. Close
inspection shows aphids to be the villains. It's planted in the soil of
the allotment greenhouse.

Main concern is preventing the aphids migrating to the newly sprouted
seedlings, in trays of compost, nearby. I need to spend some time today
with soapy water and brush them off.

Q. Can anyone suggest a spray deterrent, to prevent future attacks? I've
tried various insecticides in the past (can't remember their names) with
no luck. TIA.

Try just plain water but in the spray, with a good pressure behind it
knocks them off the plant, this in turn breaks their feeding parts so
although it doesn't kill them they die shortly after as they can't feed.
Also leaving the greenhouse door open so birds and ladybirds can get in
and do their job.

--
Charlie Pridham
Gardening in Cornwall
www.roselandhouse.co.uk