I often hear one of the reasons gardeners don’t use native plants is they spread too much. Many native plants are spreaders, some spread more than others, and a few are “clumpers”, i.e. don’t spread at all or very much. Sometimes native plants don’t look like they are doing much above ground the first few years, because they are focusing their energy below ground making root systems, then they take off. Other native plants, sometimes called pioneer plants, spread and blooming profusely the first few years, and then begin to die off or decrease in numbers, as other slower growing native plants begin to emerge. Other plants, especially woodland plants, spread profusely and bloom, then go dormant later in the season when trees leaf out or during the heat of the summer.
This is the way nature has been gardening for thousands of years! We humans, including myself, were taught to maintain our gardens by growing plants spaced apart with wood mulch spread around each plant year after year. If we want a sustainable garden we must allow plants to spread and fill in the bare areas of our garden to provide more wildlife habitat, improve the soil, and suppress more weeds. This saves us time ,labor, and money too. So here are some basic guidelines which I hope will encourage you to use native plants, both spreaders and clumpers, as living mulch.
Learn which plants are pioneers and use them to your advantage to keep weeds down when initially planting your garden. One examples: Black Eyed Susan (Rudbeckia hirta)
- Some natives spread more than others. Learn which plants are aggressive spreaders and don’t use them in smaller gardens and use sparingly in larger gardens. One example is Cup Plant (Silphium perfoliatum).
- Please note native plants are dynamic. Sometimes they spread more when conditions are right, but other times they take a back seat, when conditions are not . For example, a native perennial which typically grows in moist conditions may go dormant during a drought, while a perennial which prefers dry conditions may thrive.
- Learn which plants go dormant naturally or in extreme weather conditions, and plant other plants that emerge later or thrive in various conditions so there are less bare spots in your garden. A bare spot doesn’t necessarily mean a plant is not there, it just may be dormant.
- Plant in layers. Include some spreaders of various degrees, and some clumpers, occupying all the space in your garden. Just think of a decorative container design – Stratgically add thrillers (plants which stand out and look good multiple seasons) which are clumpers, fiillers to occupy voids between clumpers, and spillers along the ground (groundcovers or lower growing plants). This includes areas around trees and shrubs, and in perennial gardens. For examples, Golden Alexander (Zizea aurea) spreads and is a good filler, but it still allows other plants to grown in between or in other areas nearby.
- Learn which native plants grow together in the wild, something called companion plants or plant associates. Plants provide competition for each other, so if you plant companion plants, they will more likely keep each other in check. A sustainable gardener will use plants that not only look well together but grow well together, as well as in the right site conditions.
- Initially you may use wood mulch, leaf mulch or leaf compost around plants when first planting, because the plants are small when you first purchase, but eventually plants will fill in over time if designed correctly. You should use less mulch around native perennials over time as they spread, except for naturally falling leaves in a woodland garden or wood mulch around the base of a tree, especially trees without a living mulch underneath, like trees in a parkway.
- Birds, insects and other animals also disperse seeds into other areas of our garden so sometimes we have to do artful editing. We cannot have blanks areas of soil in our yards and not expect plants (native or weeds) to spread– it’s impossible unless you put a thick layer of mulch or weed fabric, but both of these can be detrimental to wildlife and plants in other ways.
Invasive plants are different because they are so aggressive, have no competition, sometimes use chemical defenses, and are very difficult to control. Since many invasive plants come from other areas, they don’t have the competition of local plants, weather or insects like our native plants do. Same goes for other species like invasive insects. Some native plants like Tall (Solidago altissima) or Canadian Goldenrod (S. canadensis), spread very aggressively and should not be used at all or removed from most gardens. But I believe when our prairie ecosystems where intact, these plants were not invasive as they are today. Unfortunately we’ve change our ecosystems so much, some native plants and other native species have become “out of balance”, a term I like to use and coined by Stephen Packard.
Hope nature will inspire you to garden with a living mulch. If you still want to learn more, please visit and study natural areas, parks arboretums, yards where native plants successfully grow. Also read our notebook article “Rethinking Native Plant Maintenance“. If you need a landscape plan, please call Good-Natured Landscapes LLC. We know how to incorporate native plants into a designed landscape, including spreaders.