Have you visited your local farmer’s market lately or picked up your weekly allotment at a CSA? If you are a locavore, like so many of us, you might be asking some pretty specific questions of your suppliers when you are vetting your food choices, such as:
- Where was this food grown? How far is the farm from here?
- Where did the seed come from? Is it heirloom? Do you collect and save seed?
- How do you grow your crops? Are all organic? Any pesticides – organic or synthetic?
- Are your methods sustainable and regenerative? Do you take measures to protect and nurture the soil?
These are all great questions that we should be asking about the food we eat and how it is grown. It’s time to ask similar questions about the plants that we buy for our landscapes.
Thinking Outside of the Big Box
As big box stores, and even grocery stores, displace more and more local nurseries as our sources for garden plants, we know very little about the “provenance” of our plants. Were they grown from seed? Where did the seed come from? Are these local ecotypes? Are the plants genetic clones? Where were they grown? How were they grown? Were pesticides used?
Not knowing the provenance of plants makes your purchase a crapshoot– the plants may not be successful in your landscape or may offer little to nothing to local wildlife. Even worse, plants grown in other regions may introduce serious new pests and diseases in your landscape.
Local Adaptations Are Your Friends
Native plants grown from locally wild-collected seed (local ecotypes) and grown locally by a reputable nursery are an informed gardener’s first choice. Native plants that persist in a particular ecological region have evolved to adapt to the conditions of that locale. The particular soil, geography, micro-climate and other factors result in native plants that are uniquely suited to their environs (aka “ecoregion”).
Imagine that you live in Connecticut in an area with wind-blown, frigid winters. Your landscape is rocky with acidic, well-draining soil. You decide to plant a red maple and you select a robust-looking sapling at a nearby garden center.
When planting the red maple you discover that the root ball is encased in a dense mound of red clay – often a giveaway that the plant has been grown in the deep South in heavy, moisture-laden soil. How well adapted will that plant be to your conditions? The outcome is not very promising.
A far better choice would be to shop at a local native nursery that has collected red maple seed from your ecoregion, growing the seed in conditions similar to your landscape, in soil similar to your native soil. These “local ecotype” plants will have the genetic makeup to flourish in your landscape conditions, while being genetically different individuals – critical to a healthy ecosystem.
Watch the EcoBeneficial interview with Kyle and Lisa Turoczi of Earth Tones Native Plant Nursery in Woodbury, Connecticut, for an example of a nursery that is doing this well. And, check out CT NOFA’s Ecotype Project, which is increasing the availability of local ecotype plants in Connecticut.
Genetic Diversity – Don’t Marry Your Cousin
While we take it for granted that genetic diversity among humans is important, we often skip that genetic rule in horticulture. Plant cloning, is common in the world of plant propagation. This comes with a high ecological cost, since genetic diversity in plants is essential to a healthy environment.
Perhaps you would like to plant Echinacea purpurea (purple coneflower). Buying plants grown from locally-collected, locally-grown seed would ensure the greatest genetic diversity, and adaptability in your ecoregion. Unfortunately, it is often very difficult to find anything but native cultivars (aka nativars) for sale.
With all cultivars, there is some loss of genetic diversity – in some cases, a tremendous loss. While some nativars can be grown from seed, most are grown asexually as clones, meaning that every one is genetically the same with the same DNA. One example of a nativar clone is Echinacea purpurea ‘Pink Double Delight’ which has been selected and propagated for its double-petalled flowers (read on…).
The Local Wildlife Connection
Supporting wildlife – birds, mammals, butterflies, pollinators, etc. – is a major reason for planting natives. Unfortunately, we often assume that all native plants within a given species, nativar or straight species, are equivalent in supporting wildlife. Do all Echinacea purpurea plants function the same way ecologically? Do all attract bees, butterflies, goldfinches to the same degree? The short answer is “no.”
Echinacea purpurea ‘Pink Double Delight,’ the clonal “kissing cousin” mentioned earlier, is quite showy, but its double flowers have displaced most of the nectar, pollen and seed that support wildlife. Any nectar or pollen that may be remaining are inaccessible to pollinators. Forget about seeds for wild birds. That nativar’s ecological functioning is dismal. Other nativars can be more ecologically useful, but it depends on the cultivar. (For more information on this topic see the EcoBeneficial video interviews with Annie White on her research at The University of Vermont on pollinators and nativars).
Through the tremendous research of Dr. Doug Tallamy of the University of Delaware, we know that there are chemical differences between exotic plants and native plants, making many exotic plants less useful to creatures such as butterflies. There is evidence that there may even be chemical differences between plants of the same species, grown in different parts of the country. More research is needed, but to be safe, plant locally-sourced, locally-grown native plants for best ecosystem impact.
Happy Plant Shopping from Kim Eierman at EcoBeneficial!
Photo: Asclepias purpurascens (Purple Milkweed)
Photo-credit: Kim Eierman
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