For annual plants, things become more complicated. As annuals only need to survive for one growing season, hardiness zones are usually not considered. Instead, we should look at issues such as soil temperature required for germination and response to warm, humid days or cool nights, both of which we are likely to see. I will use one of the AAS 2013 winners, Zinnia ‘Profusion Double Hot Cherry’, as an example to work from. Included in the description is: “Like all Profusion, ‘Double Hot Cherry’ is easy to grow as it is self-cleaning, disease resistant and grows well in a wide range of climates, including areas with high night temperatures.” Sounds like it will work here, right?As I read the description of the plant on the AAS site a couple warning signs popped up. The statement of most concern to me is: “The Profusion Double series is highly disease tolerant, but cool temperatures (below 60°F/15°C) induce disease problems; especially under wet and rainy conditions. Poorly drained soil or overwatering induces root disease.”While summers are usually warm here, several nights in a row when temperatures drop below 60 are common, and this often happens when storm fronts move through, which means rain. Soil drainage is another concern. Most Boone County soils are either poorly, or somewhat poorly, drained. This combination of factors tells me if I’m going to grow this plant I should consider either using a raised bed or planting it in containers, both of which are appropriate for it.A similar type of investigation can be used for all new landscape and garden plants.
The fact that a plant has been selected as an AAS winner is not a guarantee that it will be successful in your landscape or garden. However these plants have proven themselves worthy over a broad range of growing conditions. As with anything new, try a small landscape planting or a few vegetable plants at first to see if this variety does work for you. Keep track of what you learn to share with your friends and neighbors. Above all, have fun.
Curt Emanuel is the Boone County Extension Educator for Ag & Natural Resources and is the County Extension Director.