Why Locally-Sourced, Locally-Grown Native Plants Matter

Posted on Nov 9, 2015




Have you visited your local farmer’s market this week? If you are like many of us, you might be asking some pretty specific questions of your farmers 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? All organic? Any pesticides – organic or chemical?
• Are your methods sustainable? 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. We should ask similar questions about the plants that we buy for our landscapes, too.

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 our plants. Where were they grown? How were they grown? Were pesticides used?

Not knowing where the plants we buy come from makes our purchase a crap shoot– the plants may not be successful in our landscape or may offer little or nothing to local wildlife. Even worse, plants grown in other regions may introduce serious new pests and diseases in our gardens.

Local Adaptations Are Your Friends

Locally-sourced, locally-grown native plants from reputable nurseries 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 California in an area with hot dry summers and frigid winters. Your landscape soil is rocky clay with poor drainage. You decide to plant a milkweed for the monarch butterflies and you select a colorful-looking one at the nearby big box store.

When planting the milkweed you discover that the root ball is encased in a sandy, well-drained soil – a dead give-away that that plant came from somewhere else. 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 nursery that has collected seed from your ecoregion, growing the seed in conditions similar to your landscape, in soil similar to your native soil. These “local genotype” plants will have the genetic makeup to flourish in your landscape conditions, while being genetically different individuals – critical to a healthy ecosystem.

The Wildlife Connection

Supporting wildlife – birds, butterflies, pollinators, etc. – is a major reason for planting milkweeds. Unfortunately, we often assume that all plants are the same. Do all milkweeds function the same way ecologically? Do all attract bees, butterflies, goldfinches to the same degree? The short answer is “no.”

The tropical milkweed (Asclepias curassavica ), the one mentioned earlier, is quite showy, but its flowers have displaced most of the nectar, pollen and seed that support wildlife and it’s bloom time fosters unnatural migrations of the monarch butterflies. In other words, its ecological functioning is poor. Native milkweeds are more ecologically useful.

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-grown, locally-sourced native plants for best ecosystem impact.