Question
I have gardened for 25 years and worked a number of years in a garden center/nursery.  I am stumped on this one and fear my first year without planting annuals may be upon me.  

Five years ago I moved into a white house with a fairly large shady yard.  Zone 5.  I typically plant about 12 flats, 6 windowboxes, and several combination pots.  I have planted/tried begonias, both tuberous and dragon wing, impatiens, a few petunias, fuschia, coleus, and caladium.  Probably others, but that all I can remember right now.  I cannot keep the majority alive for a season.  I can't keep anything flowering beyond a month, if at all.  Within two weeks of planting, I am having serious problems:  no flowers, deformed leaves, poor growth, dark-spotted leaves, progressing on to very large dead and/or silver spots on the leaves and streaked stems.  

From my research, I have determined I have thrips.  I have used malathion, orthene, and spinosad in an effort to control them, all to no avail.  The products work for a very short period of time and then the thrips seem to develop a resistance to them.  I have also tried rotating the pesticide usage.  Last year I spread a perimeter of granular pesticide around the house.  With my daughter's assistance (she is a currently enrolled in a horticulture class), I have been able to determine with a fair amount of certainty (albeit no microscope) that I am dealing with the Western Flower Thrip and its associated viruses.  

Knowing I can't beat this pest, my question to you:  Are you aware of any thrip-resistant annuals I might be able to try?  

I vaguely remember reading that thrips are attracted to the lighter colored flowers.  My experience indicates this may be correct.  But once I reach a full-blown infestation, nothing seems to stop them.  

Am I doomed to a no-flower summer?  Is there any shade flower that can withstand this thing? I can't find an article on the Internet dealing with my question.  All the articles seem aimed at growers and crops.  

Thank you in advance for any assistance you may be able to give.

Answer
Susan,
Yes, you are correct that thrips are attracted to lighter color flowers. This is particularly a problem in shade as the palette of plants for shady conditions is already smaller. As far as I know, there is no flowering annual for shade that is resistant. Have you tried using Bayer Tree and Shrub (Merit), which is a systemic insecticide, along with the Spinosad? I'd also start with all new soil in containers if you haven't done that... although it sounds like you have probably tried this already. Blue sticky cards will trap adult thrips ( you can find blue here: http://www.greenhousemegastore.com/Blue_Yellow-Sticky-Cards/productinfo/PM-SCBY-... and the blue work better for WFT than yellow cards.

The other possibility is to get rid of all pesticides and buy predetory insects that feed on Thrips - one listing here: http://www.biobest.be/v1/en/plagen/trips.htm - you can't use yellow or blue sticky cards or any insect killers if you use predator insects.

Other than that, maybe going a year without flowers, and getting rid of all the old soil in pots and boxes, would help the populations dwindle. If you do this, be sure to buy yourself at least three bouquets of cut flowers every week!
all the best,
C.L.