Question
Hi there,

A few months ago my avocado plant's soil got infected with some kind of fruit flies. I bought a special spray for it,  but it didn't help. I also tried to dry it out but they still there. Two days ago, I decided to change the soil to a totally new one and I washed the roots of my avocado so it cannot have any residue from the old soil. I'm afraid now that I made a mistake and now the leaves are bending down. Is there any way that I can still save my small precious plant? Please help me.

Thanks,
Mor

Answer
Repair and recovery are delicate areas, my friend.  Transplanting is VERY hard on the plant.  Microscopic root hairs cover the roots and support growth that the roots alone cannot accomplish.  When you disturb these delicate root hairs, or when you wash them off as you did (with the best of intentions, of course), they are so damaged the plant goes into shock.

Best hope for recovery lies in careful pruning of upper growth and removing all wilted leaves.  It may be necessary to remove almost ALL the foliage to save the plant.

'Messenger', the Harpin Protein product that was developed by Cornell scientists, triggers repair mechanisms in ailing plants.  It will help your plant recover.  Best results come from spraying the leaves and stems, then watering the balance into the soil to reach the roots.  It is unfortunately not available in many parts of the country.  Look at their website to see if you can purchase it quickly:

http://www.edenbio.com/

Click on 'Home and Garden', then 'Find a Retailer' down the left side of the page.

A small amount is all you need.  It's good to have some handy in case you need it in an emergency -- like this one.

Don't bother comparison shopping.  The product is patented and not available under another name or generically.  Cornell collects royalties to support its research, so it's not cheap, but it's your best bet.

Don't overwater your plant in an attempt to compensate for the root damage.

In the future, get yourself some Yellow Sticky Traps, sold usually for problems with Whitefly infestations but also effective for Thrips and Fungus Gnats.  Stay away from 'special sprays' with a skull and bones on the label or 'Caution' statement -- you don't want to breathe that stuff in your house all year.  There are lots of safe ways to deal with these things, and they are often more effective than chemicals with names that have 25 syllables and 2 or 3 hyphens.  The Earth Is Round.

Good luck and keep me posted.  Thanks for writing.