How to use field trials for plants

A couple of weeks ago I used this space to talk about how plants are sometimes brought to market before they are really tested and trialed. As you might have guessed, I feel strongly about evaluating plants. This is done in the form of field trials or evaluation plots or sometimes they are called test plots.

In the Gateway Learning Garden in Springfield, we focus on evaluating annuals. We call them field trials, which is a fairly standard term used around the country. We have been evaluating annuals since 1998 and have looked at more than 150 plant varieties each year.

I am a firm believer in using field trial data to determine how the plants are going to perform in your own garden. However, there are a couple of things to keep in mind when looking at the numbers and the results.

First of all, consider the source. If you live in Ohio, you want to use information that comes from trials in the Midwest. For instance, the University of Georgia has a great trial program, but the plants are under very different conditions than they are here in Ohio.

In addition, soil types are also very different around the country. Our soils are very similar to what you are going to find in most parts of Ohio, except for those areas of the state that have sandy soils.

The other important factor is to look at the methods used in the trials. We don’t deadhead any of our plants and in similar trials on campus, they do some moderate grooming. In addition, we don’t add mulch to our trials and they do on campus. The results from these variables can result in different numbers.

One of the things that I find quite interesting about field trials is the fact that other than the name, there are no standard criteria for evaluating these plants. Each university, company, or organization conducting the trials has their own criteria.

We evaluate our plants on a monthly basis and then combine the monthly ratings into the overall rating average. On the other hand, in the trials at the University of Georgia trials they evaluate every other week.

We used to be really picky about what we were evaluating; we looked at the foliage, flower, height, width, etc. Then we got smart and realized that it came down to the question, “Is this a really great plant?”

After that we used a simple one through five rating system. Five means the plant is fantastic, I want it and can’t live without it! One means the plant is a real dog and I wouldn’t plant that in my garden! Simple, huh? This is what the consumer wants: simplicity in selecting plants.

You can find the results of the field trials in our demonstration garden at http://go.osu.edu/fieldtrials. The report shows you how the individual plants performed through the season as well as their final rating and photos.

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