Hi,
Your experience last summer sounds really disappointing! 

Given the large numbers you're already seeing, it's probably not realistic to handpick the grasshoppers.

One mechanical control you could consider is a protective cover, such as a floating row cover, to shield your flowers from grasshoppers. You can also spray the covering with an appropriate insecticide.

However, it sounds like you want to avoid insecticides, if possible, so a complementary chemical control that targets young grasshoppers specifically might be of interest. The information below comes from Colorado State University Extension.

Nosema locustae Baits

Baits containing the protozoan Nosema locustae is a biological control option that may be considered for treating grasshopper breeding sites. This is sold under the trade names NOLO Bait or Semaspore and can produce infection of many species of grasshoppers. Because it is selective in effects, only affecting grasshoppers, its use is sometimes considered desirable.

There are some limitations to Nosema locustae baits. Only young grasshoppers are susceptible, and it can not be used effectively after adult migrations have occurred. It is also fairly slow acting and does not equally infect all grasshopper species. Often it is most effectively used in a long-term grasshopper management program, in combination with other controls.

Nosema locustae baits are also perishable. They are best kept refrigerated before use. Expiration dates are usually printed on packages and should be checked.


I hope that gives you some useful options to protect your flowers this season.