What’s Wrong with Non Native Plants?

 

I get this question a lot. Mostly people are asking the question in regards to using non native plants in their garden (non native plants naturalizing into wild spaces is a different question not covered here). When shopping for plants, the availability of non native plants vastly outpaces the selection of native plants so choosing native landscape plants requires more time and effort.

People like to point out that the plants they are buying/using have flowers that the bees and butterflies can use, birds can make nests in the plants just as well, and of course the plants tick off all the usual reasons for landscaping: they are green, they look good, they can be shaped/controlled for size, and they illustrate that someone lives there and cares for their yard.  So when I make recommendations for specifically seeking out and using native plants INSTEAD, the questions come back: “What’s wrong with using non native plants? What do they do wrong? They are not spreading anywhere.”

The answer centers not as much on the point of what is wrong with what they do; they obviously “do” a lot for the conventional landscape (again, they’re green, they’re pretty, and they are available in all the stores). The answer centers on what they don’t do.

Luna moth - born and raised on native trees

Plants that have evolved with the insects in their ecoregion – that is native plants – have become part of the ecosystem that needs its components to thrive. Two points in particular should be considered:

1.      Host plants: Certain insects such as butterflies and moths (Lepidoptera) are herbivores, requiring certain plants on which to feed. The Monarch butterfly and its relationship with milkweed (Asclepias sp. plants) provides a well-known example. If a female Monarch cannot find a milkweed relative, she cannot lay any eggs for the next generation. If we want butterflies (and moths), we must plan for them and choose the right plants. Plants from other parts of the world did not evolve with our insects (although, in a few small cases like parsley/dill/fennel they might be close enough relatives of our native plants for butterflies like the Eastern Black Swallowtail but that is the exception).

2.      Specialized pollinators: Much like some insect herbivores rely on certain plants to raise their young, some pollinators have evolved to be specialists. My favorite example is the Southeastern blueberry bee (and there are many other specialist bees).

Zebra swallowtail - depends on paw paw (Asimina)

Southeastern blueberry bee on blueberry (Vaccinium)

While not all insects are specialists, having adapting to use more than one type of plant for eggs or able to use several types of flowers, what is true is that native insects get the most out of native plants. The large and beautiful Luna moth lays her eggs on native trees like sweet gum, hickory, and walnut. Popular non native landscape trees like crape myrtle, ornamental cherries/pears, Japanese maples and shrubs like butterfly bush, loropetalum, privet/ligustrum and gardenia don’t support insect herbivores in any sustainable way (if at all).

Oakworm caterpillars - one of the few to eat in a group

Most caterpillars are solitary and hardly noticed

You might think that not having insects nibble on your plants is a good thing, but balance that with fewer butterflies and moths to enjoy or to support birds. The vast majority of caterpillars do not defoliate plants; if you have oak trees in your yard, chances are they are supporting caterpillars and you didn’t even notice because they prefer the top leaves.

Birds want your caterpillars! Photo: Romin Dawson

So to go back to the original question, the ecological answer to ‘what’s wrong with non native plants’ is that there isn’t enough right with them to support our insects. If you’d like to contribute to the place you live in a way that supports the ecosystem, include more native plants in your design. It’s not hard to do thanks to an increase in demand for native plants and an increase in the amount of education out there. In Georgia, here is a list of nurseries that carry large and small amounts of native plants

Small Nursery Feature – Stolen Flowers Nursery

I like to occasionally profile small nurseries that sell native plants. This week is a relatively new one, having been open just a few years in Armuchee in NW Georgia (near Rome). I recently had a chance to visit this nursery and was very impressed with the quality and diversity of plants.

I first met Terri Todd last spring when she approached the Georgia Native Plant Society about donating some extra plants, particularly purple coneflowers (Echinacea purpurea), to our sale. Unfortunately we canceled our sale for 2020 but she renewed the offer in 2021, so several of us drove there to pick up her donations. All of her plants are seed-grown and raised under the canopy of large open hoop houses on site. When I saw how beautiful and healthy the plants are, I knew I wanted to let other people know about this nursery.

The coneflowers she donated to GNPS

Terri has grown flowers for some time but initially focused on growing and selling cut flowers. She became interested in native plants after reading an article about the decline in Monarch butterfly populations. She said that she “was thrilled to find flowers with a purpose and function.” She now grows at least two species of milkweed (Asclepias sp.) to help those butterflies as well as a wide assortment of native wildflowers.

The name of the nursery was very interesting to me. She said the name was taken from an experience when she was a child. She would pass through a yard with a lot of flowers as she walked to visit her grandmother. She would pick some of the flowers to take to her grandmother. The owners of the yard, Miss Love and her sister, were not happy. “I don’t recall if I knew then that it was wrong to steal the flowers, but I found out for sure that it was very wrong when Miss Love called my mother to complain about me picking her flowers.”

Terri really enjoys growing flowers from seed, watching the plants grow and develop is part of the enjoyment. That tells me that she is in this for the love of plants, and we could see how much she cared about growing a diverse and healthy selection of mostly native perennials. She is planning to add some native small trees, shrubs, and vines in 2022. Perennials are available in 4.5 inch and 1G-sized pots.

I appreciate good signage!

Her nursery is open during the growing season: April-June and September through mid-November. The hours are Thursday-Sunday, 10 am to 4 pm. The best source of information is the nursery’s Facebook page. You can find the address and phone number there. I will give a tip on traveling there: when coming from Rome via US 27, if your navigation has you turn onto South Little Sand Mountain Road; make sure you stay on the road for about 4-5 miles until you get to the 4 way stop with North Little Sand Mountain and Little Sand Mountain Roads. The nursery is 1777 Little Sand Mountain Rd, Armuchee, GA in Chattooga County. Cell reception can be spotty in the area.

For other nursery profiles or to find specific topics on this blog, use the small search box in the upper left corner of the desktop version of the blog page.

Happy, hardy native flowers growing here

A Moment in Nature for July

It's so hard to believe we are into July already and the temperatures are hot enough to make me wish I did not get another mulch pile dumped on the driveway. However, my mulch pile brings me a lot happiness! My #momentinnature for June was thanks to my old pile and this month's moment is an Eastern eyed click beetle (Alaus oculatus) that was exploring the new one.

Eastern eyed click beetle

Click beetles are ones that can springboard themselves away from danger by flexing their body. This particular adult, perhaps a female, might have been investigating the pile as a place to lay eggs. The larvae of this beetle live in and around damp, rotting wood because that is where their prey live. They feed on the larvae of wood-boring beetles, so we might consider them to be a beneficial insect by helping to keep the population of those beetles in check. Apparently, the larvae of click beetles are called 'wireworms' and some are pests of crops because they eat roots; this species is carnivorous.

The adults eat small amounts of plant material, not enough to be considered a pest in any way. I only find about one of these a year at my place. Each time it is a special occasion and another reason to celebrate a garden full of life.

Celebrating Some Native Fireworks

When I see these plants blooming, I can't help but think of fireworks. The spiky red blooms of scarlet beebalm (Monarda didyma) and the outrageous white bloom balls of buttonbush (Cephalanthus occidentalis) are just as showy as the fireworks we see this time of year. I added some blue self-heal (Prunella vulgaris ssp. lanceolata) to round out the patriotic color scheme.

 Happy Birthday, America. Let's celebrate with the plants that were here when we got here.