Hello Mr. Appleby,
We live in the foothills of the Appalachian Mountains in once of the most densely populated deer areas in the Northeast. One of the easiest tactics we use to keep deer away is also an all-natural solution. Deer Repellent Packs is the product name. The packs use the deer's inborn natural fear of predators to your advantage.
The packs are good for up to 90 days and can be hung right on the plants (raspberry/blackberry bushes) you want to protect. You can check them out at www.DeerRepellentPacks.com and they can be ordered in just the quantity you need.