Help for Midwest Gardeners: How Do I Choose the Right Plant?

Let’s say you’ve decided you want to plant Bee Balm (Monarda didyma). You go to an online catalog, and there could be dozens of varieties to choose from. How do you know which is best? You can go by the description in the catalog, which may be more or less accurate. This may purport to tell you the size or color of a variety, but won’t tell you much about how a specific variety performs in your region.

'Raspberry Wine' bee balm
‘Raspberry Wine’ bee balm

That’s where the Chicago Botanic Garden’s Plant Evaluation Program comes in. CBG tests the garden performance of large numbers of varieties and species for selected genera. So far they have produced 37 reports, all of which can be downloaded for free from their website. To visit their website, click here.

Many more are in the pipeline. Before evaluations are completed, however, perennials are tested for four years, shrubs and vines for six, and trees for seven to ten.

Of course, performance depends in part on local conditions, and different varieties of the same species may be best suited to different environments.  These evaluations, then, are most relevant to gardeners in the upper midwest. Still, gardeners elsewhere may want to take note.

This is especially true because these reports are a delight for obsessive plant nerds.

Bee Balm Raspberry Wine Wild Bergamot
‘Raspberry Wine’ with Wild Bergamot.

For example, the report on Monarda and mildew resistance evaluated 39 Monarda varieties. And the folks at CBG Plant Evaluation are tough judges. Plants are rated on a one to five star scale, and none of the varieties got all five stars. Only two – ‘Raspberry Wine’ and ‘Marshall’s Delight’ – got 4.5 stars (I have lots of ‘Raspberry Wine’.).

I was especially interested in the report on Hardy Geraniums. The report evaluated 97 varieties derived from 17 species. Again, none of the varieties earned a perfect five star rating. Only six varieties got 4.5 stars. The only one of those six I was familiar with was ‘Brookside’.

Geranium 'Johnson's Blue'
Geranium ‘Johnson’s Blue’, only fair to good, says CBG.

And 14 of the varieties flunked out completely, including ‘Bressingham Pink’.

I was interested to see how the Hardy Geraniums in my garden fared in the report. ‘Johnson’s Blue’ got 3.5 stars, just fair to good. I was a little offended on JB’s behalf, as I had always found him to be a strong perfomer. ‘Biokovo’ got four stars (good), which is consistent with my experience. And ‘Tschelda’ (Geranium renardii) got just two stars (poor). This sadly confirms my own observations, mainly due to ‘Tschelda’s’ scarcity of flowers.

I have lots of the wild Geranium maculatum, but unfortunately the straight species was not evaluated.

Geranium Biokovo
Geranium Biokovo. I took this with my phone.

Before you know it the holidays will be over and it will be time to start pouring over plant catalogs. When you do, you might want to peruse the Chicago Botanic Garden’s Plant Evaluation website for backup.

47 Comments on “Help for Midwest Gardeners: How Do I Choose the Right Plant?”

  1. Excellent advice — thank you for pointing out this resource! Hard to believe but so true that soon we’ll all be studying and selecting plants for the new season. I’m going to check out the hardy geraniums’ rankings, which should prove helpful IF I can identify the many varieties planted here before we arrived!

  2. Thanks, Jason. I have seen results of several of their trials in Fine Gardening. What we really need is a Craig’s List sort of thing for plants.Of course, that means one for your ecozone, and one for my ecozone. and one for ……. It does get complicated, doesn’t it?

  3. I have been growing Geranium ‘Brookside’ for years but then my name is Brook! It flowers so much longer than the basic form.
    Great to have powdery mildew advice on Monardas. If you get the wrong ones on my sandy soil they are a complete mess with this disease

  4. Sounds like a great resource. Will be useful for those that garden in the Midwest. Although I am not too familiar with the trials that the RHS do over here, I’m sure they don’t give them a points rating but when we see the words RHS AGM on the label, then we know it should a worthy plant for the garden.

  5. I pay lots of attention to those plant trials. Monarda is a hot mess when it’s mildewy so I have lots of Raspberry Wine, too. But in my humidity, every variety ends up with at least some mildew so I’ve just have to learn to deal with it. But some times I just have to plant a few different cultivars that are reported to be mildew resistant and see what does the best for me. But I do avoid the ones known to be mildew magnets.

  6. That looks like a great resource, even for people in other parts of the country! I’m not surprised that Raspberry Wine scored well; I have a lot of it too. It looks great in your garden with the wild bergamot.

    I would have liked to see the species Geranium maculatum evaluated too, just out of curiosity. I love it.

  7. Reblogged this on Rhymes with Linnaeus and commented:
    Here’s a handy post from the Garden In A City blog about the Chicago Botanic Garden Plant Evaluation Program. Since Southern Ontario shares the same ecoregion as the Chicago area, you’re safe to assume that the information works well for us, too. Now finding the top performing plants for your garden is just a click away. Enjoy the read!

  8. Thanks for the info: I will definitely check it out! It may not apply directly to me up here in Wisconsin, but I’m close. And it seems we have similar garden conditions, except that I have more shade and less sun than you do. I only have the straight species of Geranium maculatum in my garden–it grows prolifically here with plentiful blooms! The pollinators (and the people) love it!

  9. That is a great service to the community. I cannot even guess at how much money I have spend on dud plants — the ones that catalogues hype but never seem to perform well. The federal government used to sponsor agricutural schools across the country to do this kind of thing — test varieties of crop and ormanmental plants to see what grows well regionally. It is really a crime that those programs have withered.

  10. Plant trials are in Buffalo also. I do believe gardeners should pay attention to what grows in their locale rather than advice given from other parts of the country. Growing conditions (mostly soil, but also air with salt or excess wind as examples) can vary greatly even in short distances from the home garden.

  11. Thanks for the advice, Jason. I get emails from the Chicago Botanic Garden, but I’ve never really checked out their plant trials. For general info, I often go to the Missouri Botanic Garden’s website, which is also very helpful. One of our local MG’s sends out the results each year of trial plants in our Idea Garden, and I’ve come to depend on that a lot for picking out annuals each season. Whatever the source, I’ve learned that local or regional trials really are the best for judging whether a plant will do well in my garden, not the plant catalogs!

  12. Great information as usual. Delighted to find out about the CBG plant site. Grew up in Evanston, IL. but now garden in North Carolina. But! I’ve got a grown daughter with her first home and garden in Chicago suburbs. She will love this post, which I will forward to her. This is always a well done blog deserving kudos.

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