HORT travels

Exploring the horticultural beauty in every adventure.

Bradford Pears and Mangroves

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Flowers and emerging leaves of Bradford Pear

Flowers and emerging leaves of Bradford Pear

Road trip! I love a good road trip, and even not good road trips are fun. I am a “it’s the journey, not the destination” type of person, so no matter how terrific the final destination may be, I look forward with equal anticipation to the adventure of just getting there (and back!).  And while my philosophy even extends to plane travel (I try to watch the happenings like watching a documentary on TV, trying to learn something from the experience, or at the very least amuse myself.) I really, really enjoy a good old, fashioned road trip. A snacks on the passenger seat, kayak on the roof, taking GPS directions only as suggestions, radio up loud, windows down, let’s see where I wind up road trip.

This road trip I am heading down to the west coast of Florida. I have to admit, Florida isn’t one of my favorite states. Not enough snow or fall color for my liking. But it turns out my parents love it there and have recently decided to call it home.  They live on the water now and I love to paddle, so I threw my boat on the car, packed up too much stuff, and hit the road.  Spring was just starting to show its face when I was leaving. As I headed south, spring progressed as my miles increased. Soon I was seeing Bradford Pears (Pyrus calleryana) in full bloom. Everywhere. EVERYWHERE.

Bradford Pears are just coming into bloom in my neck of the woods. These are the white gumdrop shaped trees that bloom each spring. They smell terrible. Ugh, I shiver just thinking about it. Yuck. If you are familiar with these, you may have noticed fewer branches blooming each spring. They self-destruct. They are a short-lived, weak-wooded poor choice for a landscape plant or street tree, which is how you see many of them used.  Winds break them apart with ease. I have heard some people refer to them as the “Great American Exploding Street Tree”. Governments have used them in many landscaping projects along highways and in rest-stops. From these plantings they have escaped to invade natural corridors.

If you look closely in the woodlands, fields and stream banks around landscapes where Bradford Pears have been planted, you will surely find more in bloom. They may not have the gumdrop shape, and they may have large thorns on their trunks, but the awful smelling white flowers will be blooming at the same time as those in the manicured lawns of developments and curbside mulch beds of the local bank. And this is a problem. Bradford Pears have become, what many in the conservation and horticulture fields have termed, ‘invasive’.  Invasive is an ecological term denoting not only an aggressive tendency to outcompete everything around it, but also a negative impact on the ecology, meaning it impacts birds, turtles, insects, mammals, plants and soil, disrupting everything.  Bradford Pears were introduced to the landscape trade decades ago as a sterile plant. Many different varieties were planted, cross-pollinated and were no longer sterile. Seedlings started popping up everywhere. You can read more about this tree here. In one of the photos below you can see two small Bradford Pear trees popping up in between guardrails along the highway. Besides their spring flowers and pretty purple fall color, the fact that they grow well in nearly any landscape situation seems to make them an appealing tree for a variety of landscape uses.

Aggressive Natives

I do a lot of teaching to adults about landscape plants. When I address the topic of invasive species, someone always raises their hand and says “But I have noticed {{insert name of aggressive native plant here}} growing everywhere. Isn’t that invasive?” The answer is ‘no’. And the reason is because of the ecological impact portion of the definition. Some native plants are aggressive, it’s true. Some will escape the boundaries of your landscape beds. Some natives fill an ecological niche where it is essential to be aggressive. This is where Mangroves come in. Mangroves live where little else can, in the saline edges of salty water bodies.

Eventually I get past the blooming pears on my route and make it to Florida. My mom and I decided to explore a kayak trail through a mangrove forest along the Gulf of Mexico. As I was paddling quietly through this mangrove monoculture, it occurred to me that this is a perfect example of an aggressive native. There were very few other plants in sight while we paddled the narrow channels cut into the mangrove forest. Tiny black crabs sped up and down the ‘prop’ roots of these trees. We saw new mangrove trees sprouting high above the water, we saw roots marching beneath the surface, trying to fill in the trail carefully created by park volunteers and staff. Mangroves feed animal populations and protect human populations by buffering winds and waves at the water’s edge. If these were not tough, aggressive plants filling in voids as quickly as they occur and evolving unique ways to make new plants, they would quickly succumb leaving us with unprotected shorelines exposed to wind and waves and leaving tiny valuable creatures without a food source. Though all you see when you look around a mangrove forest are mangroves doesn’t mean these are invasive plants. They are serving a very specific purpose, they are contributing to and supporting a fragile ecosystem. They are essential. They accomplish all this because they are aggressive and successful in their niche (as long as humans don’t come along and ruin what nature seems to have perfected).

This is something to consider when choosing plants for your landscape. What ecological niche does the plant you are considering fill in nature?  Take grasses for example. Many of us want ornamental grasses in our landscapes. We think of one or two clumps standing straight and tall among our perennial borders or next to our mailboxes. But, in the natural, native, environment, what do these grasses do? Many of them fill a void. They are prairie plants. They are designed to fill a gap in the landscape caused by fire or flooding. They spread aggressively by seed and their seed germinates easily. Planting a switchgrass (Panicum virgatum) in a formal landscape may not give you the results you want. It will escape into your perennial bed, your vegetable gardens and your lawn because that is what it is designed to do. I have found the same to be true for another native grass Northern Sea Oats (Chasmanthium latifolium). I planted this in a small raised garden bed and soon had it growing all over the garden. Though I love this plant, I didn’t want it everywhere. I have also used this along a stream bank restoration in the mid-atlantic and it did just what it was supposed to do: spread everywhere, filling in gaps before invasive plants could get a foothold, providing cover and food for native animals and protecting soil from erosion along the stream.

The Plant Isn’t Bad…It’s How We Use It

Bradford Pears have become invasive here, they are not part of the native ecology. But they are not considered invasive in their native region because they are part of the ecosystem. Bradford Pears are invasive because of how we have chosen to use them. Part of what we need to understand when choosing plants for our landscapes is how they behave in their native environment, whether that is the woodlands of the state in which we are gardening or a far-off Asian forest. When we understand the role of a plant in its native environment, we may better understand how it will behave here. Sometime plants are not evaluated enough, and the repercussions of introducing it into the landscapes of very diverse and fragile ecosystems is not fully researched, as is the case with the Bradford Pear. Though I don’t think you should be planting these, and I think you should be removing the ones you have and replacing them with native plants, I don’t think they are bad plants.  (Wondering what to plant instead of a Bradford Pear for those spring blooms?) They are doing what evolution (and plant breeders) have designed them to do, they are just trying to succeed in nature, as is everything else. They happen to be very successful at it, at the expense of our beautiful native trees and shrubs, which of course impacts our native animals, soils and systems.

When you do a search online for Bradford Pear, hundreds of websites shouting “do not plant”, “invasive”, and “rip this out” show up in the results. I wanted to end this on a positive note. It is not a bad plant, though it does cause damage in our native ecosystems. It does have pretty flowers, and the (awful) smell attracts all kinds of pollinators. It is a plant used without the knowledge of the ecological niche it fills in its native environment. I wanted to tell you what a great plant it is in its native environment. I wanted to show pretty pictures of the butterflies and birds it supports, of it in full (stinky) bloom in a diverse Asian forest. Do a Google search for that.  It is nearly impossible to find out what animals this tree supports in its native countries. It is difficult to find descriptions of this plant in its native Asian environment. It is hard to learn about the tree’s natural habits, the butterflies and birds it may support in its native country. I did learn birds enjoy the fruits in early spring when not much is around to eat and the miniature pears have frozen and thawed and softened enough to eat.

We have the power to make a change in the environment, to support the birds and butterflies we love so much. All we have to do is a little research before we dig that hole and plant the most recent garden center purchase in the ground. We simply need to remember that what we do in our landscape has an impact far greater than the view out our window. What a tremendous opportunity that is!

(Though I couldn’t find much online, or in my horticultural library, about the animal associations with Pyrus calleryana, in my research I did happen upon this website documenting the Asian exploration of Frank Meyer in the early 1800s. At this time he collected seeds of Pyrus calleryana in hopes of finding those with fireblight resistance to save edible pear crops from fireblight in the US. Just think, without the discovery of this plant, we may not have all those delicious pears to eat!)

PS

Rest Stop worth Stopping For

Kingsland Welcome Center in Georgia, along 95 just after leaving Florida. They have some of their landscape plants labeled! If your road trip leaves you hankering for some horticulture, stop here and stretch your legs while exploring their landscape complete with plant labels. Did you know another name for the native (& underused) Fringe Tree (Chionanthus virginicus) is Grancy Grey Beard? I didn’t, I learned it at a rest stop!

Public Service Announcement

Should you decide to road trip down to the west coast of Florida and plan to sleep at rest stops, as I choose to do, you may want to carefully consider reading Stephen King’s Just After Sunset just before you leave. Many of the short stories in this collection are set in that area of the world and one takes place in a Florida rest stop, which is described in perfect detail. As I walked into the rest stop, I started listening, thinking I may have just walked into the story.

3 thoughts on “Bradford Pears and Mangroves

  1. Pingback: “Hortisculpture” | HORTravels

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