For people who own businesses that require employees for specific periods of time, it is a good idea to develop a list of local sources of the kind of talent needed. If you need techs, for example, perhaps there is a local vocational school or other schools that might have young people seeking work for their spring and summer breaks. Perhaps contacting other kinds of enterprises that operate in the opposite season (e.g., those catering to things like snow plowing/removal comes to mind) would help you find some people. The local unemployment office may be able to help you identify other such employers as they are usually on top of companies that lay off workers in the spring and rehire in the fall. Another idea is to provide flex hours to the degree possible and job sharing. That way you can attract people who need to work but maybe not full-time or 9:00 to 5:00. Providing a bonus for those who stay on board for the entire season may help you too.
Results can be improved with a heightened management focus on the continuous flow of strategic change. Drive responsibility for day-to-day operational revamping as far down in the organization as possible.