Wild Ones Presents “The Self-Perpetuating Landscape: Setting a Process in Motion…”

| Wild Ones Presents

Written by Sally Wencel

Larry Weaner, landscape designer and author of “Garden Revolution: How our landscapes can be a source of environmental change”, Principal and founder of Larry Weaner Landscape Associates and founder of New Directions in American Landscapes presented an information-filled webinar on November 16, 2021. In case you missed it, here are some takeaways.

Landscapes are dynamic. Plants don’t necessarily stay where you plant them. Similarly, plants often appear where you didn’t plant them. While you might consider many of those plants weeds, you might be surprised when an Elderberry (Sambucus canadensis) pops up in your meadow planting. That Elderberry might have come from a seed courtesy of a bird that then germinated and was waiting for an opportunity to grow once you stopped mowing. You can use natural recruitment of species you planted – and some you didn’t — to enhance you landscape.

Instead of managing your landscape by weeding, create dense, layered plantings that make it difficult for unwanted plants (“weeds”) to get established. Most of our urban and suburban landscapes started out as disturbed ecosystems that create opportunities for unwanted plants to become established. Dense, interlocking plant communities block unwanted plants. (For more information about plant communities, check out natural areas in your region or books on the topic.)

Plant for your conditions – match your plants to your soil and growing conditions instead of trying to change conditions to match the plants’ needs. One example Larry gave was Heuchera villosa, “Hairy alumroot”– a specialist that grows in poor, rocky, alkaline soils that will thrive where more competitive plants cannot. Instead of pumping up your soil with rich topsoil, try using Heuchera villosa along shady gravel paths that mimic its environmental niche of rocky woods. Larry also gave the example of a plant he tried to use for many years – Pink tickseed (Coreopsis rosea) – that always seemed to fail or get outcompeted by its yellow-flowered lookalike Threadleaf coreopsis (Coreopsis verticillata). It wasn’t until he realized that Pink tickseed grows in wetlands that he understood that it wasn’t that the plant was “weak” – he was planting it in the wrong place.

Use multiple recruitment strategies – include plants with multiple reproductive (seed dispersal) and clonal (spreading through rhizomes and stolons) strategies. Joe pyeweed (Eutrochium ssp.) is a prolific seed producer and is wind-dispersed so you only need to start with a few plants and it will spread widely in the landscape. Another prolific self-sower is Penstemon digitalis, although those seeds are dispersed close to the plant, creating a dense community over time. One of Larry’s favorite plants is Packera aurea, aka “Groundsel” or “Golden ragwort.” That plant spreads through rhizomatous roots, allowing it to spread from the mother plant, creating a dense, almost evergreen groundcover of attractive heart-shaped leaves. A bonus is the spring bloom of bright yellow aster-like flowers. Other groundcovers like Pennsylvania sedge (Carex pensylvanica) spread aboveground, creating a dense mat that blocks out weeds.

Use management strategies like mowing or burning during specific times (i.e., fall or spring) to favor the plants you desire to fill the landscape. Timing your mowing will advantage different species. When asked about burning, Larry offered that he doesn’t use this method due to local regulatory limitations.

When asked about his three favorite plants, Larry offered Eastern Hornbeam (Carpinus caroliniana), Packera aurea, and native azaleas.

Check out the saved chat to review the discussion. (Coming soon)