Question
I was given a very healthy looking Nerium Oleander in March 2006. I keep it outside on the balcony in a large terracotta pot. I'm in a temperate/mediterranean climate (Toulouse, France) and balcony faces west so we get the hot afternoon sun.

Last year we had a very hot, dry summer and when I came back from holiday all of my plants were badly infested with red spider mites and aphids.

I treated the plants with an all rounder insecticide and this was quite successful, but I still had problems with aphids on the oleander. One angry day in September, I cut the tree down to 3 leaves on each branch. It overwintered outside in the snow and this year in spring it bounced back to a gorgeous, bushy umbrella shape, but didn't flower. However, all of my plants were completely pest free so I wasn't complaining.

Off we went again this summer on a 7-week holiday and got a friend to look after the plants again. When I came back in August,the oleander and all of my other plants were completely overridden with spider mites and aphids. Most of the leaves had yellowed and fallen from the oleander and the branches were enrobed in webbing. The leaves that remained were heavily speckled and falling off with the slightest breath of wind.

I read online that you can mix vegetable oil with dish washing liquid and some water and spray it on the plants. This I did, and the pests seem to have gone, but my plants are losing the rest of their leaves anyway. I think the mixture burnt the leaves or suffocated the plant. I'm feeling pretty stupid about that now...

So, here are my questions:

1. The oleander has almost no leaves left on it. Should I cut it down to just above the soil level and hope it grows back? I would like to save it, if at all possible.

2. How can I prevent the pests coming back when the people who look after my plants over the summer holidays don't do anything but water the plants?

Here are a few photos of the plant.

When I received it, April 2006:
http://naryves.com/pj/france/toulouse/2006/ruegenets/garden/balconyjuly.jpg

June 2007, just before going away:
http://naryves.com/pj/france/toulouse/2007/ruegenetsmay2007/garden/laurelrose.jp...

Thanks very much in advance,
Narelle Lewis  

Answer
Narelle,

I suspect the problem is not really the insects but with very poor watering practices while you are away. Spider mites and aphids tend to attack plants that are under stress. I would first try unpotting some of your other plants and inspecting the roots. If the roots are black and mushy the plants were severely overwatered in your absence. In any case I would not cut the plants all the way off. Oleanders do much better planted in the ground than they do growing in a pot. I urge you to consider planting them in the ground. Here is a website with detailed care on oleanders from the International Oleander Society: http://www.oleander.org/culture.html

I urge you to study their site. From your pictures it appears that you have a number of beautiful plants and you do very well at caring for them. The problems only arise when someone else is careing for them. Perhaps you need to find a better plant sitter. Good luck.

Darlene