Two (or More) Sides to Every Story: What to Do with Leaf Litter

Autumn clean ups for your customers used to be a clear and distinct process. Roll in, final mow, prune and pick up, and maybe, budgeting allowing and customers willing, divide some perennials and build more garden spaces with their own plants.

Now there’s more research, a different baseline of understanding, and even more opinions about this to be found on the internet. One end of the spectrum on this topic is represented by organizations such as the Xerces Society with their campaign “Leave the Leaves.” In this marketing blitz, we are learning the importance of leaving the leaf litter for the butterflies, for instance, overwintering here, as caterpillars huddled and bundled in rolled up leaves for warmth and protection from predators. The Luna Moths we’re so fascinated with, with their dramatic wingspans and short, interesting life cycles in June, disguise their cocoons and chrysalis as dried up leaves.

When we rake up, mow, and mulch, or worst of all by some standards, use a leaf blower to corral fallen leaves, we are destroying the next generation of many, many pollinators that would have emerged in the spring and started their beneficial work for another life cycle. When you see some of the fritillary butterflies, for instance, in the spring, it’s because they were able to survive all winter, in some of the leaves left undisturbed whether in a forest, thicket, or some gardeners’ lawns who are aware of the “Leave the Leaves” knowledge and movement.

Leaving leaf litter provides habitat for many types of bees and wasps along with all the beneficial insects overwintering. More and more research is indicating that these populations are dwindling, but are essential for our food supply. If your customers are adverse to leaving the leaves and how their yards and gardens will look quite different from crisp and clean (or barren and bewildering, in some viewpoints), then the next best thing would be to gather the leaves and spent perennial material and make a corner area on the property to house that material, giving the eggs and larvae in there the opportunity to overwinter and emerge in the spring.

Another benefit to leaving the leaves, whole, and not shredded, can be to use as mulch. We see a lot of research about the whole leaves actually doing a better job of mulching than the same material shredded. The whole leaves serve to retain moisture and, as whole leaves, provide a stronger weed mat by helping suppress sunlight which helps germinate those pesky weed seeds. The Xerces Society blog, written by Justin Wheeler, points out what I found to be one of the most compelling aspects of leaving whole leaves that I have read from any source. He reminds us that when we are appreciating the spring ephemerals, we often see their “delicate” stems poking up through a leaf, or their stems weaseling through a pile of leaves. The spring ephemerals are strong, forceful, and dynamic and not dissuaded by a few leaves piled smoothly on top of their growth flight plan.

Other professional sources with interest in lawn care expertise, see many other aspects of this situation. Leaf litter for landscapers can also present other problems to weigh against the environmental focus.

One consideration of landcare professionals is the way a mat of leaves can prevent rain water from reaching to the grass roots or plant roots. Young grass may not grow in evenly, depending on the layer of leaf cover they are working against. This prevents a lush, verdant lawn many of your customers want to maintain. By removing the leaves, there will be even distribution of sunlight, water, and various fertilizers you may be using by your own preference or by your customers’ requests. A full, traditional fall clean up will result in that “look” they may be striving for.

Leaf clean up should mean there is as little disturbance as possible for the insects already mentioned overwintering in what you may have cleaned up and, in previous years, thrown into a landfill. An autumn clean up will definitely remove the places deleterious pests and mold will thrive. Check with your Cooperative Extension service or where you have a working relationship with lawn care products, to learn about the ways snow mold hatches and spreads. Learning about the molds and diseases of turf grasses, such as brown patch, will help you determine risk management about autumn clean ups in your area.

Leaving some leaves while thoroughly clearing out others seems to be a reasonable compromise as we learn more and educate clients more, about the “Leave the Leaves” and similar movements. Perhaps leaving leaves in areas where you are going to design in a pleasing garden pathway is a meaningful, beneficial and economical way to begin that process.

It’s all about education, and about learning how we fit in to the natural world. Considering helping your clients diminish the area of expansive, monoculture lawn area by removing some grass and planting some native shrubbery or perennials will be a great way to start the conversation and conversion to healthy lawns living side-by-side with habitats conducive to wildlife, including our much-needed pollinators.

—by Cris Blackstone, NHCLP

Benefits from the UNH Agriculture Experiment Station Work

Participants in the tours offered during Durham Farm Days, August 21, learned the ways that UNH’s Agriculture Experiment Station is funded. How the station conducts research projects that end up being disseminated by the Cooperative Extension to gardeners, landscapers, property managers, and everyone in between, looking for answers to their plant questions, was thoroughly outlined; and the tour covered the full gambit of projects in action right now. State and Federal monies fund the 130-year-old Agriculture Experiment Station, for the 50+ research projects conducted currently. From the proper way to prune tomatoes, to growing nutrient-rich seedless grapes – or learning which trellis mechanisms are the most conducive to healthier grape vines, every project has a keen eye trained on sustainable practices to be implemented. Additionally, Anton Bekkerman, Director of the Agriculture Experiment Station, shared that the projects each seek to developing skills and techniques successfully combating climate change. With these factors in mind, he handed the participants’ attention to Kyle Quigley, Assistant Farm Manager, who would take the first tour group around Woodman Farm, while Evan Ford, Farm Manager, waited for the second tour group to arrive and take off on the same trajectory.

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During Durham Farm Day, August 21, the UNH Agriculture Research group at Woodman and Kingman Farms led several tours showcasing their current research projects. Here, Kyle Quigley, Assistant Farm Manager, points out the projects focusing on growing figs in NH. Besides this outdoor “forest” there’s a high tunnel overflowing with healthy, productive fig plants. You have to see it to fully grasp the scope and size of the plants, which are pruned to ground level stubs, after a frost.

The projects we learned about included several on table grapes, tomatoes, broccoli, strawberries, and even figs. Projects at the site also include investigating integrated pest management (IPM) and growing hydrangeas for the cut flower industry and landscape use in New Hampshire. These projects can all culminate with landscapers benefitting from the knowledge gained through the Ag Experiment Station and shared through the Cooperative Extension – because of the increase in homeowner interest in growing edible plants alongside the ornamental trees, shrubs, annuals, and perennials on their properties.

Costs of the vegetables and fruits can be contained by learning more about overwintering strawberries, for example, or by growing strawberries from seed rather than by starting them and selling plug plants. Shaping and pruning broccoli can help those plants produce more and be easier to harvest for large scale producers as well as home gardeners. As for figs, the tour participants saw what can be described as a “fig forest” in a high tunnel and another dense stand of fig plants outdoors, with the experiment being how to overwinter after the extreme pruning the plants tolerate.

The Ag Experiment Station was strongly aware of the ways cut flowers are increasingly a consideration for home gardeners, as well as the number of specialty cut flower growers in NH who are looking for more products to sell, adding to their selections for wholesale applications. With several rows of three types of hydrangeas in their full late summer bloom, we learned which types seem most likely to overwinter with strong comeback and bloom times each year. Farms producing field cut flowers has grown by leaps and bounds – 60% increase – since 2007. There are many movements, associations, and a rising awareness of the importance of the “slow flower” movement to reduce carbon footprints from importing vast numbers of flowers, so the UNH research projects are quite welcome to help the end users realize their role in sustainability when flowers are locally grown. The hydrangea project will reveal not only plant hardiness but will indicate valuable information about vase life for the flowers as a commodity.

Before this tour, I was aware of different ways to trellis and train grapes to grow, but I would have said the trellis mechanisms were regional, or cultural, or related to the type of grapes being grown. During this tour, we saw different trellising mechanics and learned the research is showing that the nutrients in grapes can even be enhanced by the different trellises used, by how they offer differing degrees of light, air, and direct sunlight. Our tour guide was a master of sharing the complexities of the research in a way that made it clear to understand and integrate, and he encouraged questions from the tour participants. We learned to distinguish between two main trellis types and were able to walk down a lengthy row of vines which had been planted in 2014, to see the differences. Under the netting protecting the vines from birds, we were able to also see different vines with different stages of ripening and were reminded not to taste test the ripe grapes. Taking even a few grapes during a tour like this would be to remove valuable data points for the research project – to everyone’s disappointment!
Kiwiberries, also grown with trellising mechanisms, were a part of this tour. We learned about the research geared toward standardizing the size and shape of the kiwiberries as well as how in some places they are considered invasive and in other places there is a strong interest in growing them for commercial use. You may have seen Martha Stewart’s extensive property in Maine, with a wall of the kiwiberries on it, preceding her ownership of the property. There was a time when kiwiberries were considered more popular than wisteria for landscape use and were grown by nurseries for these ornamental purposes. Now, they are being strongly considered as a product for their “super fruit” nutritional value and the UNH project is contributing heavily to this area of interest.

If you’ve toured the Woodman Farm site before, you may remember the pollinator meadow areas, which were projects conducted by Dr. Cathy Neal and that received international acclaim for knowledge gained about bee’s preferences. Those meadows are in full bloom this time of year and as Dr. Neal told during her tours, the asters are taking over a bit. She did remind us at the time of her tours that meadows are not static, and different flowers in the mix will self-seed and dominant flowers will wax and wane over time. In full glory, the meadow areas were not only vibrant with colors and textures of seed heads, but teaming with small birds, butterflies, and many types of bees, taking in the nectar provided.

Integrated Pest Management (IPM) projects are conducted on a regular basis, since so many commercial products are on the market and gaining acclaim or notoriety in the fight against various pests. Learning more about IPM could take a full day, and that part of the farm was the turnaround point of the tour.

Heading back to the starting point, there were several projects showcased. From how to grow Brussels sprouts – how to prune the plants, or to let them grow long stalks as we may be more familiar with. How many sprouts result from each method of growth is being analyzed. The bushy form of the pruned plants is a lot different than the stalks with the sprouts circling the stalk!

Projects with tomatoes and how to prune or shape those plants competed with my excitement at finding a fungus growth blowing around the pathway. It was feather-light, and the flat side, which I thought was the bottom, was soft as velvet. The side I thought must be the top, looked something like a delicious mound of chocolate frosting that would fit on a large cupcake. It turns out Evan Ford could immediately identify it for me, as I delicately carried it to where he was and I wanted to perch it on a good background to capture it in a few photographs. It was a common mushroom, one the bright white non-poisonous “fairy ring” mushrooms (Amanita thiersii) which sometimes grow as big as a softball, and their spores thrive in fresh grass clippings. (It turns out that to prepare for the Farm Day, extensive mowing in the field rows and paths had been going on several days prior to our tours.) This object I had in hand was actually upside down as I held it – when turned the other direction, Evan demonstrated with his hand that it was a mushroom which had been sheared by the mower, and this part was the underground part which had been uplifted as he explained it to me. I know from watching some of these in my own lawn, that they do turn a doeskin shade of brown/beige pretty quickly, but I had never seen the part that was supporting the stem or ball, from its undergrown perspective.

All in all, I would highly recommend you take advantage of touring the Woodman Farm as a landscaper curious about how research is conducted and to see a few steps ahead of the trends your clients may start to ask about. From cut flowers to edible landscape plants, vegetables have been elevated to such status, you will see what it takes to go from a serious question with financial ramifications to sustainable answers. Ultimately many of these research projects end up as our new baseline of understanding and expectations of the plants we work with.

—by Cris Blackstone, NHCLP