Be A Better Gardener: Native Annuals

Be A Better Gardener: Native Annuals

By Thomas Christopher

In my last column, I discussed the unique aesthetic potential of annual flowers. Today I want to share the equally unique benefits that annuals, or more specifically native annuals, can provide to your garden’s ecosystem.

This is information that was shared with me by Ethan Dropkin, a Cornell University-educated landscape architect who is currently an associate and horticultural specialist at Larry Weaner Landscape Associates in Glenside, Pennsylvania. Larry Weaner Landscape Associates has been one of the principal forces in the ongoing movement to integrate ecological principles into American landscaping, and Ethan has been a trailblazer in that effort. I recently shared the conversation I had with him on the “Growing Greener” podcast I produce for the Berkshire Botanical Garden.

Ethan began by reminding me of the role that annual flowers play in the natural landscape. An annual, according to the botanical definition, is any flowering plant that sprouts from a seed, grows, flowers, and produces seeds itself all within one annual growing season. This accelerated schedule enables annuals to serve a special function in healing the landscape after some disturbance such as a flood, a windstorm, or a fire. When that event strips the vegetative cover from the land, exposing it to erosion and the sun, annual seeds lying dormant in the soil sprout and grow up to provide a Band-Aid until more durable but slower-growing members of the flora such as shrubs and trees can regenerate. Before these more persistent species crowd them out, the annuals drop another crop of seed onto the soil, arming it against the next disturbance.

What does this matter to a gardener? Consider how many smaller, hopefully less catastrophic disturbances affect your landscape on a regular basis. Maybe your puppy digs in a flower bed, uprooting a few perennials and leaving a patch of bare earth. Or you open up a patchwork of small gaps with a vigorous episode of weeding. Maybe winter kills a frost-sensitive plant that you had hoped would be hardier. Or a hungry deer browses a shrub back to a stub. You get the idea. Weeds will rush in to colonize the gap if you leave it untended, and they will compete, often all too successfully, with neighboring garden plants. The most effective way to forestall such an event, and reduce your weeding time, is to intersperse your displays of flowers and shrubs at planting time with some native annuals.

Identifying annuals native to your area is easy, thanks to the efforts of the Lady Bird Johnson Wildflower Center in Austin, Texas. The Center has developed a searchable “Find Plants” database that is available for use free on its website (www.wildflower.org) under the heading “Plant Information.” Among the options on this database is to search only for plants from a particular state, plants of a particular “Habit” of growth, and for plants of a particular “Duration” or lifespan.

I discovered this last summer when I was hunting for annuals I could use to patch my meadow in western Massachusetts after a tree service drove over it repeatedly with a tracked log skidder. When I searched for “Massachusetts,” “Herb,” and “Annual,” I was rewarded with descriptions and photographs of some 408 annuals indigenous to my area. Many, such as annual ragweed (Ambrosia artemisiifolia) were not something I wanted to add to my garden. However, I did come across a couple of species such as black-eyed Susans (Rudbeckia hirta) and partridge pea (Castilleja coccinea) that were adapted to the conditions on my site and which promised to harmonize with the existing meadow grasses and perennials.

Such native annuals are not featured in local garden centers, but an online search turned up sources for the seeds. This was an economical way to add the plants to my damaged meadow: a pound of partridge pea seeds, for instance, cost me only $41.40 including shipping, handling, and sales tax. I broadcast the seeds in mid-fall – I knew that winter cold and moisture would help them overcome dormancy, enabling them to sprout in the spring. As of this writing, I am waiting for the soil in my garden to warm and growth to begin.

What began as a mishap, thanks to native annuals, turned into as an opportunity to add new color to my meadow and increase its resilience and biodiversity. To learn more about how these plants can benefit your garden, listen to my conversation with Ethan Dropkin on the “Growing Greener” podcast at the Berkshire Botanical Garden website: www.berkshirebotanical.org.

Be-a-Better-Gardener is a community service of Berkshire Botanical Garden, located in Stockbridge, Mass. Its mission, to provide knowledge of gardening and the environment through a diverse range of classes and programs, informs and inspires thousands of students and visitors each year. Thomas Christopher is a volunteer at Berkshire Botanical Garden and is the author or co-author of more than a dozen books, including Nature into Art and The Gardens of Wave Hill (Timber Press, 2019). He is the 2021 Garden Club of America's National Medalist for Literature, a distinction reserved to recognize those who have left a profound and lasting impact on issues that are most important to the GCA. Christopher’s companion broadcast to this column, Growing Greener, streams on WESUFM.org, Pacifica Radio and NPR and is available at berkshirebotanical.org/growinggreener

Be-a-Better-Gardener is a community service of Berkshire Botanical Garden, located in Stockbridge, Mass. Its mission, to provide knowledge of gardening and the environment through a diverse range of classes and programs, informs and inspires thousands of students and visitors each year. Thomas Christopher is a volunteer at Berkshire Botanical Garden and is the author or co-author of more than a dozen books, including Nature into Art and The Gardens of Wave Hill (Timber Press, 2019). He is the 2021 Garden Club of America's National Medalist for Literature, a distinction reserved to recognize those who have left a profound and lasting impact on issues that are most important to the GCA. Christopher’s companion broadcast to this column, Growing Greener, streams on WESUFM.org, Pacifica Radio and NPR and is available at berkshirebotanical.org/growinggreener