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After I posted a shot of the above seedling Geranium, Scott, of Rhone Street Gardens, asked what was the best Geranium for fall foliage color. I will now answer that question in my best lawyerly fashion: it depends.
If you like orange, it's hard to beat Geranium 'Bob's Blunder'.
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The dark espresso leaves turn a warm orange.
Another good orange is the foliage of Geranium macrorrhizum.
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But as can be seen from the photo, there's a lot of yellow in there too.
The foliage of Geranium 'Blogold' (Blue Sunrise) is chartreuse for most of the growing season, but in autumn, it turns bright yellow and red.
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It's still blooming.
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Its cousin Rozanne (Geranium 'Gerwat') displays four colors at once, the fading green, yellow, orange and red.
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But, as I told Scott at the time, the best, most consistently colorful Geranium for autumn foliage is the native G. maculatum.
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Its red leaves shine like a beacon in the sunlight, and on cloudy days provides spots of interest among the dried, fallen leaves.
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Really, all of them are great for adding color to the autumn garden, and all of them are great garden plants.
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Here's a late addition.
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It shows the difference between Geranium maculatum on the left and Geranium sylvaticum 'Mayflower' on the right.
*Pelargoniums, which are often called geraniums, are not related to any of the plants in this post and are not hardy here in Zone 5.