You cannot prevent them totally but you can control them fairly easily. There are many "recipies" for dealing with them from just spraying high pressure water on the plant to using acephates. I find that using Neem Oil on a regular basis makes them a non-issue. Spider mites hatch out about every 5 days so I spray once a week during the time they are around. The secret is to not let them get started. Inspect your plants for the mites themselves, usually on the underside of the leaves. If you see the webbing it is too late for easy control. They are very tiny bugs and the best way I have found to inspect my plants is to place a sheet of typing paper under the plant and then shake the plant vigorously. You can then see if you have them as they will crawl around on the paper. Use a magnifying glass too. If you have them spray both sides of the leaves with the Neem Oil @ 2oz per gallon of water.
How do you spray them? They are on my rosemary plant and when I it outside to spray with water the soil got soaked so I had to replant it in dryer soil.
Just get a pump up sprayer. Do you replant every time it rains? Of course you don't.
No its an inside plant, but I can't really spray it unless I want the soil the get wet and I don't want the soil that wet because It's a rosemary.
Then get a pint or a quart spray bottle. This isn't rocket surgery. And the soil will only be damp on the surface. Does rosemary ever live outside where it gets wet? Of course it does. Getting wet will not harm a plant unless it gets wet too often.
