Summer Gardener’s Corner

August 16, 2022

With Director of Horticulture Eric Kimbrel

At the transition to warm summer, we begin looking for fruit and seed production on plants so that we can be ready to collect them if needed for propagation. I was walking by some bear corn, also known as cancer-root and Conopholis Americana, and I noticed it was changing color to tan and dark brown. I picked one of the “kernels” off and left it on the table over the weekend. When I returned, I noticed the kernel had dried up so I opened it to see what, if anything, was in there. There were about 150 shiny light brown seeds with angular sides, similar to very tiny kernels of corn. This perennial plant is eaten by bears and deer and is edible by humans, but the weirdest fact about it is that it is achlorophyllous or non-photosynthesizing. So where does it get its energy? From other plants. That’s right, it’s parasitic to oak and beech trees. We will scatter these seeds at the base of our oaks, and in two or three years we should see pinecone-like structures emerge from the base of the trees in late winter and spring. These are the flowers and all that will be visible above the ground.

Another parasitic plant I want to mention is endangered only because of the small area where it occurs — the mountains of Tennessee, Virginia, and North Carolina. Buckleya distichophylla, or piratebush, is a rare shrub in the sandalwood family. Believe it or not this area also has another parasitic plant in the sandalwood family: Pyrularia pubera or buffalo nut. This really speaks to the diversity of plants in the southeast. Relatives of these two plants are only found in faraway remote places like the Himalayas, etc. We were recently gifted some seedlings of piratebush from our friend Jack Johnston. We will plant some near hemlocks and try some other spots to see how they do.

We’re collecting Spigelia right now. In past years we’ve been unsuccessful in our timing. This weekend we left some of the green seed pods on a paper plate in our workshop, and on Monday it seemed a mouse had snacked on them. We moved them to a closet shelf and safely closed the door. Later that day, we found more seed hulls broken and realized the seed pods were exploding. So, now we know why we could never catch them in time to collect in the wild.

We’ve taken note of a large crop of butterfly bush (Buddleja davidii), on Highway 64 between Cold Mountain Road and the entrance to Lake Toxaway. Though widely promoted on garden sites and at big box stores, butterfly bush is an invasive species according to the U.S. Forest Service. It reproduces quickly, grabs space from native plants and throws off the balance of the food chain. Some preferable alternatives for the home pollinator garden include Eutrochium fistulosum (Joe-pye weed), Rudbekia hirta (black-eyed Susan), Lonicera sempervirens (coral honeysuckle), Asclepias tuberosa (butterfly weed), or any other type of milkweed.

Gardening and managing land are a constant juggle of priorities related to plant health, storm water management, and aesthetics. Each layer must be considered in developing daily, weekly, and seasonal tasks. This time of year we prune hemlocks and maple trees to reduce canopy in areas of our gardens that need more filtered sunlight and canopy release for conifers. Canopy release, or making room for other trees to grown in a particular patch of sunlight, is a best management practice in forestry, specifically for red spruce trees.

We’ve reached max or peak foliage production with most species at this point in the growing season. And as a result, we use this opportunity to edit the garden. We weed and prune species that are no longer welcome or just need to be reduced to keep pathways open and hold the integrity of the original design or genus loci (spirit of the place). Weeding is a consistent editing practice and therapeutic task for staff and volunteers at SHR. Pennsylvania smartweed is flowering this time of year and easy to spot with the pink bloom. We hand-weed this from the garden beds and discard into our compost pile. Buffalo grass and blue-eyed grass are also easy to identify and weed this time of year.

The summer rhythms and routines are often broken up by new discoveries and delights. It’s never boring in the garden.