Summertime Green
Summertime Green
We gardeners can get carried away with always focusing on colorful flowers and foliage. Yes, such is important to a beautiful garden and landscape but don’t forget the GREEN! I find myself enamored with summertime’s green leaves, the sizes and shapes of leaves, and level of translucency in the leaves. Our intense summer sunshine (we’re at the latitude of Lisbon, Portugal) illuminates this attribute to a tee.
Some plants have leaves with unique symmetry and architecture, or an arrangement that really makes them stand out. Other plant’s leaves function almost as canvas for a painting, with an ever-changing display of light and shadows. From prairie to woodland, there are certain plants that stand out and should be selected in good garden design for these little discussed characteristics.
Leaf sizes from small to large translate into the “texture” of how a plant is perceived in a landscape. Fine textured plants have tiny leaves while coarse textured plants have larger leaves – each really stand out from the average or medium texture found in an elm tree for instance. Honeylocust is a favorite fine-textured leaf of mine, along with ‘Amersfoort’ yew (Taxus baccata cultivar) with its shorter, widened evergreen needles. Catalpas and some magnolias are favorite coarse textured trees. Umbrella magnolia (Magnolia tripetala) exemplifies coarseness in an exceedingly graceful way as they float in umbrella-like swirls near the end of each stem, undulating in a breeze.
If botany class made your eyes glaze over when talking about a plants leaf arrangement, it does matter in plant aesthetics! If plant leaves are set alone, alternating along a stem they are called alternate. Leaves paired along a stem are called opposite, while leaves set in clusters of 3 or more radiating from a node of a stem they are called whorled. The latter two often create a marvelous repeated pattern while alternate leaves can zig and zag down a stem in a similar synchronized way.
Leaves are also classified as simple or compound – simple leaves have one blade but vary widely in shape. Compound leaves comprise multiple leaflets that may come off the leaf’s stem (rachis) like a feather (called pinnately compound) – think walnut and hickories; or like your fingers (called palmately compound) as in buckeyes and horsechestnuts (Aesculus). And yes, some plants are doubly pinnate creating wonderful patterns reminding me of living herringbone pattern – Kentucky coffeetree, and the underutilized Devil’s Walkingstick (Aralia spinosa).
Shapes of simple leaves that grab attention include sassafras as leader of the pack with its 3-shaped leaves from simple to mitten and ghost (2-thumbed) leaves. Post oak with its outlandishly rounded lobes look almost like a jigsaw puzzle when one looks up through their leaves. Tulip tree (Liriodendron tulipifera) is another that really stands apart in this class – there is nothing else like it.
All plants’ leaves are there to capture the sun’s light energy but some stand out in how it illuminates the leaf when viewed from below. Those held in horizontal plains, often understory plants that need to capture ambient light are especially memorable. Red mulberry and pawpaw really stand out here with their large simple leaves and hickories (especially shellbark hickory Carya laciniosa) with their pinnately compound leaves.
Symmetry and architecture in foliage is most striking in sturdy perennials. I find tall coreopsis, Culver’s root, cup plant, and Virginia mountain-mint showcasing this to a tee in my own garden. They have sturdy vertical stems with repeating pairs of opposite leaves (whorled in Culver’s root), as fine as the structure of a skyscraper.
Prairie dock is the artist capturing the lights and shadows of its prairie home with its large, sail-like leaf as canvas. Defying the laws of nature with a big leaf in a bright locale, it has tufts of hairs that help hold a cool layer of air at its surface (touch one on a hot day and feel this air conditioning system). Its relative the compass plant also excels here but has wonderfully lacerated (botanically called laciniate) leaves that break up the captured composition.
So don’t forget to pay closer attention to all the green leaves in your yard or garden. Do you have a great diversity of leaf textures, shapes, and patterns? If not, add some that will contrast with what you have and you will be amazed how your garden will be enhanced – not an increased appreciation for the often overlooked beauty around you.
Alan Branhagen is Director of Horticulture of Powell Gardens, Kansas City’s botanical garden.
To view images of the green leaves described, visit the online version of the July 2016 issue at KCGMAG.com.