Zionsville Times Sentinel

February 12, 2014

Selecting new plants for the garden and landscape

Curt Emanuel Boone County Extension Educator, Agriculture and Natural Resources
Zionsville Times Sentinel

---- — The 2014 growing season may seem to be a long time away; however as we move into February, it is time to think about spring landscaping and gardening.

If you are thinking of adding something new, either to your landscape or your vegetable garden, there are many available sources of information. One I recommend is the All-America Selections (AAS). AAS is an annual list of outstanding landscape and garden plants selected following each growing season by judges who evaluate how they performed at various designated trial grounds. Some of these trial grounds are managed by professional horticulture companies, while many are public locations such as botanical gardens or museum grounds. Many are located at universities. While being selected as an AAS winner is no guarantee that a plant will work for you and your situation, this is a good source of information if you’re looking to try something new. The AAS website is: http://www.all-americaselections.org//index.cfm. The site contains information about the organization, how it works, how plants are judged and selected, etc. The list of winners can be found by clicking on the link “AAS Winners” just below the AAS logo. Keep in mind not to just look for this year’s winners but for those from past years as well.

What I want to focus on is what to look for in the plant descriptions to determine whether they are suitable for Central Indiana.

For landscape plants and flowers, an obvious early step is to look at pictures and descriptions. If you don’t care for the color of the blooms, or its mature height is 4 feet and you’re looking for something that grows to 2 feet, you can eliminate these fairly quickly.

Once you move past physical appearance, the next area to assess is environmental factors. I typically begin by looking at climate. For perennial plants, we should focus on USDA Plant Hardiness Zones. Boone County is located in Hardiness Zone 5b, where plants should be able to withstand low temperatures of 10-15 degrees below zero. Higher numbered zones indicate plants suited for a warmer climate, which should be avoided, while lower numbers indicate plants that are more winter-hardy. For our area, plants suitable for zones 1a through 5b are appropriate, though with plants adapted for extreme cold, be sure warm summer temperatures aren’t a problem.

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.