The Annapolis Horticulture Society Newsletter April 2017 No. 176

On Wednesday, April 5, Andrea Wulf will speak about her book, Founding Gardeners. Andrea Wulf is the author of five acclaimed books. The Brother Gardeners won the American Horticultural Society 2010 Book Award and her books Founding Gardeners and The Invention of Nature were on The New York Times Best Seller List.

Andrea has written for many newspapers including The Guardian, The LA Times, The Wall Street Journal, The Atlantic and The New York Times. In 2014, she co-presented a four-part BBC TV garden series and she appears regularly on radio.

The Invention of Nature won the Royal Society Science Book Prize 2016, the prestigious Costa Biography Award 2015 and the Royal Geographical Ness Award 2016 in the UK, as well as the inaugural James Wright Award for Nature Writing 2016 (Nature Conservancy) and LA Times Book Prize 2016 in the US, and the Bayerische Buchpreis 2016 in Germany. It was a finalist for the Kirkus Prize 2015 and was shortlisted for the Andrew Carnegie Medal for Excellence in Non-Fiction 2016 and the Cundill Prize for Historical Literature 2016 (Canada). It was chosen as one of The 10 Best Books of 2015 in The New York Times. The Invention of Nature will be published in 23 countries.

Andrea is a popular lecturer – she gives more than 70 talks a year. She has lectured widely to large audiences at the Royal Geographical Society and Royal Society in London, the American Philosophical Society in Philadelphia as well as Monticello and the New York Public Library amongst many others – and recently she gave a talk to 15,000 people at the Esri User Conference in California (see http://www.andreawulf.com/2009/05/endorsement-of-events.html for reviews of her talks). She also regularly appears on radio and TV.

Bring your checkbooks—AHS has purchased some of her books and we can buy them at quite a savings—only $12 per book! Please join us for conversation and light refreshments at the St. Anne’s Parish Hall at 6:45 p.m. The program will start promptly at 7:15 p.m.

From the Plant Sale Committee: To date, just a handful of members have contacted us with plants that they will be providing for the sale. We need all members to get involved. Even a single division from your garden helps. Please help out with one of the many activities leading up to the sale. The proceeds from the sale help the Annapolis Horticulture Society fund its great speakers.

We need to coordinate the plants to display and appropriately mark them. For that reason, we can’t accept plants the day of the sale. Take a moment, look around your garden and send Kathy Mooy an email kmmooy@gmail.com with some items you plan to donate. If you cannot bring plants to the potting party, one of the committee members will collect them.

Listed below are some important dates. We will have sign-up sheets at the April 5th meeting, as well.

April 8 - Potting Party, Joyce Stefancik’s house (800 Old County Road, Severna Park). 9 a.m.

April 9 through May 5 - Ongoing watering and maintenance of plants.

April 29 - Pricing at Joyce Stefancik’s house (800 Old County Road, Severna Park). 10 a.m.

May 5 - Transport. Drivers are needed to gather and place plants in their own vehicles to keep overnight and deliver them to the sale first thing the next morning. Pickup will be between 1 and 4 p.m. on the 4th.

May 6 - Plant Sale, 7 a.m. to noon. Volunteers needed to set up, sell and break down.

Prior to the sale we need folks to distribute flyers. They will be produced and available for hand out at the April 5th and May 3rd meetings.

If you wish to sign up to help, but won’t be at the 4/5 meeting, please contact one of the following committee members:

Kathy Wilson: km.wilson@verizon.net

Kathy Mooy: kmmooy@gmail.com

Sandy Allen: sandycay1@verizon.net

We are counting on you!

The Annapolis Horticulture Society

Our mission is to provide a forum for plant lovers to share information about horticulture. Meetings are held the first Wednesday of each month, from September to May except for January, and are open to the public. Enter St. Anne’s Parish Hall from Charles Street or

through the rear entrance off the South Street parking lot. The meeting will be cancelled if Anne Arundel Community College is closed for the afternoon due to inclement weather.

New members are always welcome. Membership dues for 2017-18 are $25 for individuals and $35 for households. Membership benefits include a monthly newsletter, an annual picnic, periodic workshops, field trips and garden tours. Checks, payable to AHS, should be directed

to Cynthia Chess, 8 Revell Street, Annapolis, MD 21401. The Annapolis Horticulture Society Newsletter is printed eight times a year for the members of the society. News, articles, events and other announcements for the newsletter should be sent to Debi Mallonee via email at debimallonee@verizon.net or call her at 410-647-4277.

Entries must be received by the 10th of the previous month.

Annapolis Horticulture Society Board 2017 President………………………..Diana Keener Past President………………….Bonnie Pavlak Vice President………………….Barbara Wise Secretary………………………..Bobbi Reichwein Treasurer………………………..Cynthia Chess Newsletter Editor……………….Debi Mallonee Membership……………………..Dave Mauriello Program Chairs…………………Anne Van Allen/Dave Leaverton Public Relations…………………Barbara Van Horn

Annapolis Horticulture Society Chairs IT Support……………………….Dave Mauriello Webmaster……………………..Judy Mauriello Trips……………………………..Nancy Carter and Tish Iorio

Plant Sale………………Kathy Mooy, Kathy Wilson and Sandy Allen

page 2

March brought us many new members. Please welcome them when you see them at future meetings!

Kim Forry Susan Gibbons Carolyn Gorsuch Antje Hlavaty Maryellen LaVerdiere Deborah Noyes Charlotte Pennington

Kathleen M. Potts Amy Reese

Returning members: Anita Sargent Deborah Werre

The Evolution of Controlling Weeds Part IV Controlling Weeds by Mulching

by Dr. Francis Gouin, Professor Emeritus University of Maryland, College Park, MD

Every year, Mother Nature mulches her forests with needles of pine, juniper, spruce and fir, as well as leaves from trees, grasses and herbaceous perennials. She mulches her meadows and grasslands with the residue of the previous year’s growth. However, she only applies a thin layer of mulch every year and allows it to compost on site before applying a new layer. Commercial growers of horticultural crops make extensive use of plastic mulches to control weeds, conserve moisture and keep fruits and vegetables from coming into contact with the soil. Black polyethylene is commonly applied in growing tomatoes, peppers and melons with trickle irrigation lines placed underneath for watering and feeding. But two major problems result from the use of plastic mulch: the difficulty in removing it after the crops have been harvested and the fact that it fills landfills where it will not decompose. To mitigate these problems, manufacturers are experimenting with biodegradable plastics. However, biodegradable plastics are made by infusing starch into the plastic. This means that small pieces of plastic residue will remain in the soil long after the starch decomposes. How this will affect the soil’s physical properties is unknown. Organic mulches such as straw, salt hay, bagas (husks from sugar cane), ground bark and leaves have been used for mulching a variety of horticultural crops. Straw and salt hay are used because they are generally free of seeds. Never mulch with hay if you want a weed free garden. Yearly removal of salt hay from marshes was found to cause a decline in the health of the marshes and such sourcing is now discouraged. Straw mulch should not be applied around tomato and pepper plants until the soil temperatures are above 70 degrees F. Over the past 30 years we have witnessed a mulch mania with markets flooded with ground wood products sold in bulk or bagged. These products contain ground barks and chips as well as waste from discarded wood pallets and demolished buildings. Yearly applications are being encouraged to achieve a fresh mulch appearance. Much of the dyed red, yellow, brown and black mulches are also made from discarded pallets. Problems arise when waste wood is used for making mulch: the roots of shallow rooted plants or newly transplanted plants compete with microorganisms that decompose wood and seek the same nutrients. Plants mulched with these materials will decline rapidly from nutrient starvation. In addition, hard pesticides and lead base paint potentially contaminate this waste wood made from pallets and old building materials that are being used to make mulch. Many pallets are treated with pesticides to prevent exportation of wood-boring

insects. Stink bugs are native to Southeast Asia and accidentally came into this country in wooden pallets. Thus, there is a need for the hard insecticide use.

Yearly applications of wood fiber mulches, without removing the previous year’s layer, will result in suffocation of roots. Repeated use of wood fiber mulches derived from hardwood species can also result in the accumulation of manganese, which can lead to the decline and death of ornamentals. This problem is occurring with greater frequency. As manganese accumulates, plant roots are unable to absorb iron from the soil, thus reducing chlorophyll efficiency. In most instances, where manganese levels are in excess, the only solution is soil and plant replacement. Too ‘mulch’ of a good thing! Paper mulches are being used in the commercial growing of vegetables. Since paper is made from cellulose, it decomposes and becomes part of the soil complex. Paper mulches coated with aluminum paint are being used to control insects, particularly in growing squash and cucumbers. The polarized light reflecting from the aluminum coating repels the adult cucumber beetle, especially early in the growing season before the vines and foliage shade the paper mulch. Many home gardeners use discarded newspapers to mulch their gardens. To be effective, 8 to 10 sheets of layered paper is necessary to provide acceptable weed control. But keeping the mulch in place can be a problem. It is best to use shredded paper because it will mat and stay put once it is watered down. Since the ink of all newsprint is made from soy, it is harmless and biodegradable. Nearly all colored inks are biodegradable making them harmless as well. Glossy paper is also safe to use because the gloss is achieved with a slick layer of clay. Red colored plastic and paper mulches have been tested to increase tomato yields. This is based on research that clearly indicates that plants react positively to enhanced red light. This response appears to be only temporary because as soon as the foliage shades the red colored mulch the plants resume normal growth. Clear plastic can only be used as a mulch providing the soil has been fumigated in advance. Melon growers use clear plastic mulch in order to obtain an early crop. A soil fumigant is applied in the fall and immediately covered with the clear plastic. The clear plastic provides the greenhouse effect causing the soil to warm earlier in the spring thus allowing for early planting.

Enough said.

Page 3

In Review by Debi Mallonee

Helen O’Donnell, from Bunker Farm in Dummerstum, Vermont, spoke about “The Dynamic Annual and Perennial Garden” at the February meeting. Helen had lovely slides of gardens in which she has worked, such as Great Dixter, and more slides showing other gardens that she has created for clients. She spoke of the processes that make a garden dynamic: change/growth, sensitivity to place, gardening as art and personal style or voice.

Ms. O’Donnell first considered sensitivity to place. She spoke of the layout at Great Dixter; how what had once been acres of mown grass is now a meadow, full and wild and only mowed once a year. In spots, the meadow comes right up to the house, making the home seem touched by that wildness that once was tamed and is now set free. Other gardens that embrace this sensitivity include Luciano Guibbiliei’s garden in Morocco that has swathes of native pennisetum underneath the trees in an olive grove; Thuya Garden in Northeast Harbor, ME which has a Japanese-inspired design surrounded by native evergreens and Abbey Aldritch Rockefeller’s garden, which is cultivated within walls, but outside the walls, native moss and ferns overtake the landscape. In addition, the garden of Derek Jerman, in Dungeness, England, utilizes art forms that mimic the power plant towers that loom on the horizon beyond that garden. All of these show a true sensitivity to

their surroundings.

The concept of gardening as art was also addressed by Ms. O’Donnell. She referenced the Charlotte Molesworth garden in Kent, England where the topiaries have been shaped into magical creatures. She also talked about the personal style, or gardener’s voice. The slides she used to illustrate this were from Woolbeding Garden in Kent, England where the oaks had been underplanted with native campanula.

Ms. O’Donnell moved on to talk about different ways to use annuals in the garden. The first considered was succession planting. This is when the same plot of ground is used to showcase multiple displays. This frequently requires a VERY full greenhouse and/or many potted plants that can be added or removed. It does allow for impressive showy gardens that never seem to have a brown leaf or overblown flower. On this topic she referred to a designer, Tom Bodett, who is in the process of developing a way to create low maintenance succession plantings. I’m sure that Ms. O’Donnell will be the first to know about it as he is one of her neighbors in Vermont.

The final slides showed different methods for planting annuals. If you plant them in blocks they show great import from a distance. Each block of annuals will be colorful and showy. Thuya Gardens was shown as an example. They have blocks of plantings that burst with color.

Another method of annual planting is planting as threads. This has small bright spots threading throughout the design. Great Dixter was brought up as an example. In one Dixter garden they interplant the mountain spinach (from the amaranth family) with annual Queen Anne’s Lace. The lacy white spots mixed in the dark green of the spinach, lightens up the darkness and gives it a magical appearance.

Emergent annuals is a method that lets the annual be itself. Annuals are chosen to suit the design, then they simply ‘emerge’ as they would naturally. Slides of amaranths pushing up below a heavy stand of woods was one example. Pennisetum “Vertigo” showing dark red and huge was another. Both of these effects do not last long. They fade, and in doing so, another planting can emerge.

Meadow-style planting was another method of planting annuals. Our highway managers have taken this idea to heart and one can frequently see displays of cosmos intermingled with tall salvias on the roadside.

The program closed with a few quick slides and with multiple questions form the audience.

page 4

Review of the Lewis Ginter Winter Symposium by Tish Iorio

Wow, yesterday’s program was a winner.

First up was Tradd Cotter, a microbiologist, professional mycologist, and organic gardener, who is exploring mushrooms as a type of organic pest control. The work he is doing is just fascinating. He is also very funny. www.mushroommountain.com

Next was Alex Niemiera, professor in the Department of Horticulture at Virginia Tech. He spoke about tree bark. His pictures of various trees with patterned bark were wonderful. The American beech, known for its very smooth bark, is beginning to suffer from a new fungus that will in all probability consume many of them in the United States. Scientists are working feverishly to find some kind of remedy. He then showed photos of the shagbark hickory (see photo to right), lacebark pine, winged elm, ginkgo, prickly ash and kapok tree (remember when life jackets were stuffed with the surroundings of the fruit of this tree?), Crape myrtle—which is another plant with a looming problem due to scale. There are a few systemics that control it, but not without killing other beneficial insects in the process.

David Culp spoke next about his home, Brandywine Cottage, in Pennsylvania. He discussed the inception of the project, his vision and how it was developed over the years. Though there was a lot that was in his book, the talk really was a walk through a process, then re-process when he got things wrong. He talked about why layering was so important as it provides not only beauty through all the seasons, but also year-round food for pollinators.

After lunch…

George Coombs, Research Horticulturist at Mt. Cuba, reported on the results of 4 perennial trials: coreopsis, heuchera, baptisia, and monarda. The results are available on these and some earlier trials can be found on Mt. Cuba’s website: www.mtcubacenter.org/trialgarden

David Culp assumed the podium again. He focused on the trends in horticulture from a grower/landscaper’s point of view. It was interesting. Five million of the 90 million millennials, are interested in gardening! In addition, more men (42% of them stay-at-home dads) are gardening…mainly buying at big box stores for other ‘manly’ things! Mr. Culp talked about how the name of course offerings affects attendance. A class called “Changing Your Lawn” failed, while the same class named “Planting a Meadow in the City” filled quickly! He also noted that the downy mildew problem with impatiens caused the annuals market to founder because they were such a huge part of summer annual buying. He commented that natives and nativars are surging and that nursery growers are scrambling to catch up.

Tradd Cotter finished the day with a talk about using mycelium in habitat restoration; rain gardens for pollution control; and site engineering.

So much good stuff.

It was a wonderful day. One of the best winter symposiums I have attended in the last 8 years.

page 5

Calendar of Events

page 6

Brookside Gardens

Spring Lecture Series Colston Burrell; “Native Plants in your Garden - Lessons from Nature and Culture.” Thursday, April 20, 7-8:30 p.m.

Native plants are currently the height of fashion, but do we really know what is native, and where? When we plant a floodplain species in an upland situation, are we gardening ecologically? Are cultivars native? These are a few of the questions Burrell will explore as he examines the current popularity of landscaping with native plants from an ecological perspective. Course #30443. Registration required. Free. Visitors Center Auditorium. For registration and information see: ActiveMONTGOMERY.org

Historic London Town and Gardens

Annual Spring Plant Sale and Garden Workshops April 21-23. Friday, April 21, 4-7 p.m. for members and volunteers. Saturday, April 22, 9 a.m. - 2 p.m. open to the public. Sunday, April 23, (times to be announced) Join us for Earth Day weekend.

Our annual plant sale returns, featuring an emphasis on native annuals and perennials. Among the plants available will be vegetables and herbs, azaleas and rhododendrons, flowering annuals in baskets and flats, and plants found in London Town’s horticultural collections. Bags of soil with kits to make a small fairy or dinosaur garden will also be available for purchase. Members and volunteers receive a 10% discount on purchases through the weekend.

On Earth Day, create a miniature fairy, dinosaur, or a beach garden with your little one! $30 members, $35 non-members. Fee includes pot, soil, pebbles, sand, moss, figurines, choice of plants and other decorative materials. Multi-child discount, $5 off each additional child’s garden.

Registration link available soon. For more information see: http://www.historiclondontown.org/events

Ladew Topiary Gardens

Spring Lecture Series David Culp; “The Best of Yesterday, Today and Tomorrow.” Saturday, April 5, 10:30 a.m.

Join David Culp, lifelong plantsman and award winning writer and lecturer, as he shares a behind the scenes view and unique perspective of the horticulture industry. David will present an overview of perennial plants that have stood the test of time, from old classics to current trends. He will explain what makes a trend, and share what the next one might be. David’s book, The Layered Garden, will be for sale. For further information, see: http://www.ladewgardens.com/EDUCATION/Adult-Education/Lecture-Series

The Ninth Annual Garden Festival Saturday, May 6, 2017

Garden Festival has become the most anticipated specialty plant, garden ornaments, and antiques sale in the region, featuring an exclusive collection of vendors from throughout the eastern seaboard. Garden Festival guests can shop from more than 45 vendors offering hard-to-find perennials, annuals, shrubs and trees, unusual exotics and container specialties, decorative garden furniture, urns, statuary and other architectural treasures. For further information, see: http://www.ladewgardens.com/EVENT-CALENDAR/Garden-Festival

National Arboretum

Friends of the National Arboretum Garden Fair and Plant Sale April 28, 10 a.m. - 1 p.m. (members only) 1 - 4 p.m. (Open to the public) April 29, 9 a.m. - 4 p.m.

The annual Garden Fair and Plant sale features new, rare, and hard-to-find plants, garden supply vendors, books, children’s activities, refreshments, entertainment, and more. Bring your garden questions to National Arboretum staff for expert advice. Call FONA at 202-544-8733 for more information. Free admission.

Dave Mauriello205 Arundel Beach RoadSeverna Park, MD 21146

Buy Your Own Copy at the Meeting!