I have always had a penchant for those souls who wear their hearts on their sleeves. There is a vulnerability that comes through that makes me want to help take care of them. Also for me, this penchant extends to plants with heart-shaped or cordate leaves. From lindens and redbuds to katsuras and brunnera, these plants are the Valentines of the plant kingdom, showering us with their heart-shaped leaves and welcoming us into the garden with everything they have to offer.

Centuries ago, the curative qualities of a plant were thought to be reflected in the parts of the body they resembled. This theory was known as the Doctrine of Signature and precedes the Christian Era. Lungworts (try marketing these delightful plants under that name) were thought to help restore the lungs, and their scientific name, Pulmonaria, also defines them as being related to the lungs. Walnuts were thought to restore the brain, as the kernels of these nuts looked like the cerebellum of a human. (Mysteriously, all these years later, we still think walnuts are good for the brain and I find that they provide me with a sense of calm when I grab a handful as a snack.) So maybe there really is some divine plan.
But whether or not one believes in such divine design within the plant kingdom is immaterial when it comes to cordate leaves, because they serve the heart in another manner. Aesthetically, these plants, particularly those with more perfectly symmetrical leaves, such as the redbud and the brunnera, cheer the soul. Some varieties of brunnera, such as ‘Jack Frost’ and ‘Looking Glass’, seem to shimmer in their silvery tones like a shiny Valentine received from a best friend in the second grade.

At the same time, their small, blue forget-me-not flowers add a more romantic effect. And the soft leaves of redbuds and katsuras (particularly the variety ‘Red Fox’ of the latter, with its purple-toned leaves) seem to draw us in closer to look at their emerging leaves. They captivate us with the individual beauty of each leaf.

The redbuds precede their heart-felt display in early spring with fluorescent pink flowers that are reminiscent of a magenta Crayola, like the one I used in the third grade to color a Valentine for my mother. (Personally I prefer the white flowers of some of the cultivated forms of redbuds to the magenta of the species, but must admit that all the weeping varieties of this species suit me, whether pink or white, as they seem to rain hearts down from above with their graceful weeping branches). I give my heart to all of these plants, but must admit that the genus that most romances me with its cordate leaves is the linden.

Lindens bear heart-shaped leaves that have an innocence beyond that of any other. For there is something about their asymmetrical leaves that gives them the guilelessness of a hand-cut valentine offered by a child. Perfect in its imperfection. And the blooms of these trees are known for their fragrance, a scent so invitingly sweet that these trees are commonly known as limes, although they have no relation to the citrus that bears the same name. And throughout the universe of 19th century German bildungsromans (and a few American romances of the same era), young lovers took promenades in the lime walks, where they often encountered love for the first time. I may have left my heart unten der linden, and underneath these heart-shaped leaves it will always reside. And as described by the doctrine of signatures, it will be nurtured and healthy. Of this, I am sure.
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A gardener grows through observation, experimentation, and learning from the failures, triumphs, and hard work of oneself and others. In this sense, all gardeners are self-taught, while at the same time intrinsically connected to a tradition and a community that finds satisfaction through working the soil and sharing their experiences with one another. This column explores those relationships and how we learn about the world around us from plants and our fellow gardeners.