by OCMGA Master Gardener Tammy Borden
When I moved to the country and a home surrounded by beautiful, mature trees, I was thrilled at the prospect of filling each corner and pathway with beautiful woodland perennials. I thought I found my paradise for growing what had become my obsession — hostas. What could be better for growing this tough, shade-loving perennial than towering trees that provided high, filtered shade? So, with shovel in hand, I began digging. In some areas, the soil was a beautiful, rich loam. But, to my surprise, I had difficulty slicing through the ground with my spade in some locations. While the soil was still beautiful, there was a mass of fibrous roots. Despite my concern, I decided to plant my beautiful established hostas that I brought from my previous home.
Within two years they shrank to one-third their size in the new location. The competition from the tree roots was too much for my beloved hosta to endure. Through the years I became accustomed to this battle in certain areas of my yard and have made adjustments with some success. Here are a few tips that will hopefully help if you battle a similar problem.
I have a new fondness for hostas in containers. I am especially fond of cobalt blue containers, which contrast beautifully with the many shades of hosta leaves. I am overjoyed at the results. If you choose to plant hostas in containers, make sure you give
them enough room, keep them well-watered, and after they have died back in the fall, bring them into your garage. I had some hostas double in size in one season using this method. I love placing them out in the garden among other perennials. The added height and color of the containers adds interest and a great focal point.
Where I’m determined to plant hostas in the ground in competitive root situations, I have resorted to planting them in two gallon (or more) black plastic pots and burying them right in the ground. I left several in the ground over winter and they came up beautifully this spring. Obviously, this can eventually limit the size of your plant, so bury as large of a pot as you can and plan to lift it out every few years to divide. There are large pliable mesh containers used in the nursery trade that are coated with copper hydroxide on the inside. The chemical regulates and deters roots growth of the nursery stock planted inside the pot. When hostas are planted in containers that are turned inside-out (so the coating is on the outside), exterior roots from surrounding plants and trees are deterred from penetrating the mesh. Some online forums rave about this method and I hope to trial it this year.
Planting the Right Tree
If you plan on planting a tree with the hopes of beautiful perennials beneath its shady canopy, keep the following good and bad in mind.
The Good: Top picks for friendly tree roots
• Oak – White, Pin, Burr, and other varieties
• Ash – although the threat of the Emerald Ash Borer makes this a futile choice
• Japanese Maple
• Shagbark Hickory
• Japanese Chestnut
• European Larch
• Japanese Tree Lilac
• Pagoda Dogwood
• Honey Locust
The Bad: Trees with invasive tree roots • Box Elder
• Maple – Silver, Norway, and Red
• River Birch
• Hackberry • Spruce
If You Can’t Beat ’em, Join ’em
In some locations in my yard, I have become resigned to the fact that I cannot grow hostas. I have dug them out and relocated them to a friendlier location. Rather than abandon the perennial bed completely, I have found some plants that seem to coexist with those pesky roots. While these varieties don’t thrive, they do well enough to warrant their placement:
• Japanese Painted Fern
• Lady in Red Fern
• Lamium (ground cover)
• Sweet Woodruff (ground cover) • Perennial Geranium
Give some of these techniques and recommendations a try. I’m still battling in some areas, but I’m determined to win!