When I first encountered the hosta cultivar ‘Sum and Substance’ I hated it immediately. I loathed what most people loved: the giant, chartreuse leaves. To me, they looked chlorotic (a term used to describe a general yellowing of plant tissue). Chlorosis is common in a number of our woody plant species, including maples, sweet gum, and oaks (especially pin oaks). In these hosts, it’s usually due to a nutrient deficiency. The ultimate cause may be a lack of specific nutrients (usually iron or magnesium) in the soil, or it may be due to a condition that is reducing the plant’s ability to uptake these elements. Waterlogged soils can interfere with nutrient uptake, so we’ve been seeing a lot of cholorotic plants at the Plant Clinic this year.
As I was walking through a garden a few days ago, I came across a bed with my old enemy, ‘Sum and Substance’ hosta. As I curled my lip and looked at them, I realized to my surprise that I didn’t dislike them as much anymore. I think it’s because I’ve seen so many true chlorosis samples that I can easily pick out the differences between plants that are supposed to be yellow/green, and plants that are suffering and yellowing as a result. The hosta plants look robust and healthy, and they do not have the dark green veins that we usually associate with chlorotic leaves in woody plants. In the picture, note the uniform foliage color in the healthy hosta plant on the left, and the dark green veins that stand out on the chlorotic maple leaves on the right.
I still prefer dark green plants, or the traditional white variegated hosta, but I understand the appeal of yellow/green foliage. It can make a stunning background and it makes other colors POP in contrast. I’m just happy that I can see these popular hostas without the “that plant is so stressed” reaction kicking in.
For more information about nutrient chlorosis in woody plants, see my recent article in the Home, Yard, and Garden Pest Newsletter here.