I was going to say something about allowing the bark to breathe, too. If the plastic pipe holds moisture against the bark, it could rot and kill the tree anyway. Make sure there is air flow, and room between the inside of the pipe and the tree bark. Maybe prop the bottom of the pipe up on a rock so air can go through, and water can drain out.

I use Repel on my daylilys..it is in a bottle bought at Lowe's stores..
It is a spray that has garlic etc in it.

I spray just a few of my perennials in a flower bed or every 4th plant
to save money and s pray..

You might be able to spray each tree an area the size of a saucer
and do this once every week..

It works and has for 10 years here for me..none of my flowers have been nibbled on
if the spray is on some of the plants and applied after a heavy rain and or applied
once every 7 days..small area sprayed..

sheri/sheridragonfly

http://www.lowes.com/pd_552078...

here is one that will work..

They have some more listed and you can read the reviews
by those that bought it.

I used one called Repels All by Shotgun.
I just went outside to the cabinet and it is COLD outside ...
to look to see what I have
Let us know what you do and how it works

we feed wild deer here daily for the last 15 years there are sometimes 9 of them and babies and a buck at times here around my flower beds so you know
what I bought works..
sheri /sheridragonfly

http://www.lowes.com/ProductDi...

this one says it does keep deer away.... just as the one I bought does
I read the reviews and a person said it kept them off her roses

and I think that some companies must pay people to do bad reviews on
products..of competitors..

so sometimes we just have to try ourselves
or ask others who have tried a product..some wrote horrible reviews on every
spray for deer on the site..

I wish people were honest.. but I find they do that on all sites online
from selling mattresses, to appliances, to hairdryers, to gardening supplies.

Sheri/sheridragonfly