Month: February 2014

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Planting for Pollinators

“All urban greenspaces offer potential for pollinators, and all can become important links in a chain of wildlife habitat winding through developed land. At the most basic level, healthy greenspaces mean healthy people and healthy communities. And at the core of a healthy environment are the pollinators.” –excerpt from the book, Attracting Native Pollinators by The Xerces Society

Concern for pollinators, particularly bees, is widespread. Whether you pay attention to the news or not, you are most likely aware that something is up. The bees are disappearing and no one seems to know why. Of course, most of the news concerning dying bees is in reference to honey bees, largely because they are major agricultural pollinators and producers of honey. But there are two things that many people may not be aware of: 1. Honey bees are not native to North America – they were brought over from Europe by early settlers – and 2. North America is replete with native pollinators (including numerous species of bees, butterflies, beetles, and wasps) and they, too, are threatened (partly due to non-native honey bees, but we won’t get into that here). Oh, and there is a third thing, we do know why bees and other pollinators are disappearing, and it’s not because of cell phone towers or other wacky ideas that have been proposed.

Actually, pollinator decline is due to a whole suite of things. As much as we like to seek out the silver bullet – the single cause with a single solution that will solve the problem – this issue (like so many others) does not have one. Habitat degradation and loss, the spread of pests and diseases, extensive pesticide use, and climate change all play a role in pollinator decline. Consider a modern day farm: acres and acres of a single crop planted from one edge of the field to the other, often planted with an herbicide resistant variety of crop so that all plants (both weedy and non-weedy) can be sprayed and killed leaving only the crop in question to grow competitor free. Or consider an urban landscape: patchy green space amidst miles and miles of pavement, concrete, and rooftops, and when that green space occurs, it is often a chemical green lawn free of weeds or a flower bed loaded with non-native ornamentals, bred for aesthetic appeal and often lacking in wildlife value. Our modern landscapes just aren’t fit for pollinators.

But things can change. The problem is complex, but there are small things each of us can do that when added up can make a colossal difference. Creating pollinator friendly habitats in our communities – spaces that are free from pesticides and include diverse food sources and nesting sites – can help ensure that pollinators will survive and thrive. Here are a few guidelines and resources to help you create pollinator habitat in your yard or neighborhood:

– Find a sunny location: Pollinators are most active when it is warm, so find areas that get at least 6-8 hours of full sun (just like you would if you were planning a vegetable garden).

– Plant a wide variety of plants: Something should always be in bloom during the growing season, so select at least 3 plants that flower in each of the 3 blooming periods (spring, summer, and fall). Early spring bloomers and fall bloomers are especially important. Also, in order to attract a wide range of pollinators, select plants with varying heights and growth habits and that have flowers of various colors, shapes, and sizes.

– Plant in clusters: On each foraging trip, bees visit the flowers of a single plant species, so plant each species in small clumps.

-Provide nesting sites and a water source: Bumble bees nest at the bases of bunchgrasses, so include a warm season bunchgrass like little bluestem in your yard. Ground nesting bees require a section of bare ground, so lay off on the mulch. Construct and install bundles of hollow stems (like bamboo or elderberry) in order to provide nesting sites for mason bees. Also, include a birdbath or something with a ledge for pollinators to perch and drink.

There are many resources that can instruct you on providing habitat for pollinators. One standout is The Xerces Society. They are “a nonprofit organization that protects wildlife through the conservation of invertebrates and their habitat.” Their website is loaded with information: specific plant recommendations by region, instructions on how to provide habitat for certain pollinators, alternatives to pesticides, etc. You can even help them by becoming a citizen scientist. Other excellent resources include Monarch Watch and The Great Sunflower Project.

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“Simple decisions about selecting plants, providing nest sites, minimizing disturbance, and reducing pesticides can make a dramatic difference between a green, manicured, but lifeless landscape, and one that teems with the color, energy, and life of buzz-pollinating bumble bees, rapidly dashing hummingbird moths, and busy nest-building leafcutter bees.” –excerpt from Attracting Native Pollinators by The Xerces Society

Stay tuned for future posts about pollinators, including pollinator conservation and specific pollinator and plant interactions. Also, comment below to share what you are doing to help pollinators in your community. 

Related Posts:

–In the News: Declining Insect Populations

–Figs and Fig Wasps

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Book Review: Seedswap

Seedswap: The Gardener’s Guide to Saving and Swapping Seeds by Josie Jeffery

Continuing debate and concern over genetically modified crops has resulted in increased interest in heirloom and open-pollinated seed varieties. The communities and groups that have emerged from this movement are both the impetus and the target for Josie Jeffrey’s recent book, Seedswap.

Seed swaps are nothing new, of course. Humans have likely gathered in some form or another to exchange seeds since the invention of agriculture, but recent interest in saving, sharing, and trading seeds parallels the GMO debate and the rise of urban agriculture. In that regard, Jeffrey’s book is a timely resource for anyone interested in joining the seed banking, seed swapping, and seed activism movements.

While much of this book is devoted to explaining the how-to’s of seed saving (including specific information on how to grow and save seed from 49 vegetable, herb, and flower varieties), the content that really sets it apart from other seed saving guides is, unsurprisingly, the focus on seed banking and seed swapping. Jeffrey provides a brief history of seed banks, the reasons behind them, descriptions of some of the more prominent ones, and some tips for starting a seed library. For seed swap novices, Jeffrey’s advice concerning where to find them and what to expect when attending them, as well as tips and etiquette to keep in mind are incredibly useful. After spending a few moments with Seedswap, every gardener should find themselves inspired and motivated to start saving and sharing seeds.

Jeffrey’s book is beautifully designed and well put together. Apart from the fact that it jumps around a bit and could stand to be better organized, it’s a nice little reference for anyone involved or looking to be involved in the world of seeds.

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‘Tis the season for seed swaps. Find fellow gardeners to swap seeds with here.

Related Posts

–Starting Seeds Indoors: The Planning Stage

–Seed Swaps

–Onion Seed Viability, etc.

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Horticulture Students Wanted

“Horticulture is under siege.” At least that’s the claim made in a letter and action plan penned by the top administrators of six prominent horticulture institutions based in North America. In their letter addressed to “Colleague[s] in Horticulture,” they claim that among the general public there is a “lack of horticulture awareness and poor perception of horticulture careers”. This has lead to low enrollment in high school and college horticulture programs and a dearth of qualified, young horticulturists entering the work force. Because the youth of today “appear to have little or no awareness of the importance and value of horticulture,” they are not choosing to pursue “interesting, challenging, and impactful careers” in the field.

In order to address this issue, this team of horticulture professionals has developed a plan “to increase public awareness of the positive attributes of horticulture.” Plants are essential for life on earth; humans could not exist here without them. It is the field of horticulture that supplies humanity with much of the food that it consumes, including fruits, vegetables, nuts, and herbs. Horticulture also fills our landscapes with plants that provide the backdrop to our daily lives, transforming otherwise drab and harsh urban areas into lush green spaces. And speaking of “green,” horticulture is helping us save our planet. Through teaming up with engineers and other professionals, horticulturists are helping to develop solutions to issues like climate change, water quality, storm water runoff, energy production, and biodiversity loss. Innovative and emerging strategies such as green roofs, wildlife gardens, carbon sequestration, biofuels, and sustainable agriculture require horticulture expertise in order to succeed.

These are just some of the benefits of horticulture that the authors of this plan hope to share with the general public in an effort to change public perception and attract young recruits. If they don’t succeed, the consequences may be dire – or at least that’s how they make it sound. An article on philly.com regarding the recent letter put it this way: “if something isn’t done soon…horticulture could become a lost art and a forgotten science.”

Yeah, it’s a bit dramatic sounding. It’s hard for me to believe that the situation is really that desperate. However, what I will say is that a career in horticulture is not for everyone. It certainly isn’t for anyone who dreams of being rich and/or famous one day. That’s probably not going to happen. People who choose a career in this field do so because they have a passion for plants, a love of beautiful, inviting landscapes, and perhaps a proclivity for fresh, homegrown fruits and vegetables. A career in horticulture is not glamorous by any means, but it is highly rewarding – at least from my perspective. So sure, youngsters should consider it…but they should also consider themselves warned.

And now it’s time for show and tell. I graduated with a degree in horticulture at a four year university in the intermountain northwest. After that, I ventured off to the Midwest to pursue a graduate degree researching green roof technology. Perhaps the following pictorial of some of my adventures will inspire a few of you young folks to consider a similar path. Either that or there is always that liberal arts degree you’ve been dreaming of…

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As an undergraduate, I helped manage a student-run organic farm

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I had a community garden plot overlooking the rolling hills of the Palouse

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I took a jet boat trip up the Snake River to help prune an abandoned apple orchard

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Then I went to Illinois to study green roof technology as a graduate student

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I presented my research findings at a big conference in Philadelphia

And so can you…or something like it. Comment below if you would like to put in your plug (or caveat) for pursuing a career in horticulture. The world needs you.

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Wise Management of Invaded Plant Communities

Late last year the journal Nature published an article by Katherine Suding called “A Leak in the Loop,” which discussed the findings from long-term observations of an invaded plant community in Hawai’i. (A report authored by the researchers can be found in the same issue of Nature.) Once introduced, exotic species can become invasive by modifying their surroundings in such a way that ensures their survival and spread. Examples include modifications to fire and disturbance regimes, nutrient cycles, hydrology, and soil microbe communities. This self-reinforcement strategy is called a positive feedback loop. However, positive feedback loops are not eternally stable and can at some point be interrupted by negative feedback. In the case of invasive species, these “leaks in the loop” can result in population declines  and opportunities for restoration.

Back in the 1960’s, woodlands in Hawai’i Volcanoes National Park that were traditionally dominated by Metrosideros polymorpha, a flowering evergreen tree in the myrtle family (Myrtaceae), were invaded by a perennial grass from Africa commonly known as molasses grass (Melinis minutiflora). Molasses grass was successful because its presence increased the frequency and size of fires which reduced populations of native plant species without negatively affecting itself. Additionally, accelerated nitrogen cycling rates resulted due to the presence of the exotic grass, which benefited the invader. But now things have changed.

Returning to these sites 50 years later, researches have discovered that nitrogen cycling rates have returned to pre-invasion levels. Since molasses grass requires high levels of nitrogen, it is now on the decline. What exactly caused this reduction in nitrogen availability is unclear. It could be because winter rains flush nitrogen from the soil, making it unavailable when the grass begins to actively grow again in the spring. Several years of reduced growth resulting from reduced nitrogen availability diminishes the grass’s initial contribution to accelerated nitrogen cycling, hence a breakdown in the positive feedback loop.

With the invader on the decline, the woodlands should be able to restore themselves. Ideally, anyway. Instead what the researchers observed is that another invader, Morella faya – a nitrogen fixing evergreen shrub from Europe, is moving in. Acacia koa, a native nitrogen fixing tree, is the ideal candidate for restoring these woodlands, however its seeds are heavy and don’t spread easily. Seeds of M. faya are bird-dispersed, and so they find their way into these sites first. In order to restore these sites and avoid further invasions, land managers must recognize when and where molasses grass is declining and start planting Acacia koa trees in large numbers, getting them established before M. faya arrives.

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Acacia koa (photo credit: eol.org)

This research is important for anyone in the business of managing invaded plant communities. As Suding concludes in her article, “this new perspective will inform where and when we might best intervene in systems to capitalize on their changing dynamics.” Millions of dollars are spent each year in an attempt to reduce and ultimately eradicate invasive plant species. Long-term studies of invaded plant communities can help us recognize when the best times to employ restoration strategies might be. When we find a leak in the loop, we should take advantage of it, otherwise we may just be wasting resources.

Related Post:

Invasivore: One Who Consumes Invasive Species