Insects

Aphids are usually green but also can be reddish brown.  Whatever their color, they're tiny, soft-bodied, disgusting creatures that appear in congested numbers on tender rose growth and buds and suck on everything in sight.

Thrips are microscopic winged insects with a color preference; they're partial to whites and pastels.  Thrips are suspected when buds that seem on the brink of beauty suddenly collapse with brown-flecked petals.  To see thrips you have to break a bloom apart and shake its petals over a white cloth while looking for quick, tiny movements.

Mites are microscopic (I/75 inch in diameter) spiders that are usually red, although some are green or yellow.  The spider mite's calling card is a web left underneath leaves at the bottom of a bush.  These pests suck leaf juices, rendering foliage a dry red, yellow, brown, or gray.  Hot, humid weather and poor air circulation create fertile conditions for mite infestation.

Unfortunately, the diseases and insects I've just described don't exhaust the list.  I haven't mentioned diseases such as crown gall, canker, and botrytis, or insects such as whitefly and rose midge.  That's because I've never dealt with them, and with luck you probably won't either.  There's a full discussion of these and more garden scourges in Compendium of Rose Diseases by Kenneth Harst.  To get a copy, send fifteen dollars to APS Books, 3340 Piloy Knob Road, St. Paul, Minnesota 55121.

I learned a hard lesson about insects peculiar to an area when I moved my rose growing from San Francisco to Petaluma.  One day I came in from the field clutching a bug in my fist, exclaiming that I didn't know there were green ladybugs.  There aren't.  I had seen my first Diabrotica, better known as cucumber beetle.

Cucumber beetles go right for the kill--the bloom.  What's more, they fly and they reproduce themselves in a matter of days.  It's not easy to eradicate cucumber beetles, but when you see your blooms being nibbled away before your very eyes, you learn how.