Unlike many gardeners in the upper states of the country who are still having winter, we’ve turned the corner and have been enjoying several days of spring-like temperatures. Hopefully, we won’t have too many of these days until the danger of frost has passed. For folks looking to escape the cold, we’d like to invite you to our Winter Open House, starting this week, Friday and Saturday, February 25, 26, from 8-5pm. Our Open House also continues next weekend, March 4, 5 at the same times. We’ll be opening up the shipping greenhouses for shopping, as well as the display gardens for exploration and photography. As always, we’ll be here to answer your gardening questions…we look forward to seeing you! Visiting Information
Garden photography has geared back up as the winter-flowering plants begin to put on their wonderful show. As I was laying on my stomach photographing Helleborus niger over the weekend, I was amazed to see all the honeybees visiting the flowers. This got me thinking about the ways many of the winter-flowering plants attract pollinators in a season where insects aren’t at their greatest abundance. It seems that a majority do this through fragrance. Starting with winter-flowering shrubs and small trees, fragrant plants include Hamamelis (witch hazel), Prunus mume (flowering apricot), Edgeworthia (paper bush), Michellia maudiae and Michellia floribunda (winter-flowering magnolia), Magnolia denudata (Yunnan magnolia), Mahonia x media (Oregon Grape), Daphne odora (winter daphne), and Mahonia gracilis (Mexican grape). Fragrant winter perennials and small bulbs include Nothoscordum sellowianum (yellow false ipheion), Narcissus (winter daffodil), Symplocarpus (skunk cabbage), and Iris unguicularis (winter-blooming iris). Despite my nose not being able to detect a fragrance from the hellebores, there is obviously something that the insects can detect. Although we don’t offer shrubs and trees, we hope you will consider adding more fragrant plants to your winter garden.
Over the last few years, there have been a number of Helleborus niger hybrids to enter the market. These include crosses of Helleborus niger and Helleborus argutifolius (Helleborus x nigercors), Helleborus niger x Helleborus argutifolius x Helleborus lividus (Helleborus x ericsmithii), and Helleborus niger x lividus (Helleborus x ballardiae). We have now tried 18 different clones, and while all are nice, the one that has really impressed me recently is Helleborus x ballardiae ‘HGC Pink Frost’. It’s been difficult for breeders working with Helleborus niger to get great amounts of color saturation in the flowers, but this is the exception. The flowers emerge a lovely shade of pink and darken as they age. I think you’ll really love this one if you haven’t tried it yet.
With plants popping quickly in our region, it’s time to wrap up some of the winter maintenance chores in the garden. If your clumps of ophiopogon or liriope are burned from the winter, these can be cut back now before the new growth begins. The same is true for epimediums, which are much easier to cut back before the new flower stalks begin to emerge, and for us, this is only days away. Ornamental grasses that look beat up from the winter are also ready to re-sprout, so don’t delay cutting these back or you’ll be cutting the new leaves as well as the old ones. Evergreen plants like aspidistra, ruscus, and danae hold onto their foliage for several years, and as you can imagine, the old foliage can begin to look ragged after two seasons. I like to go through these clumps now and remove the oldest foliage to keep the clumps looking their best.
If you want to do some really interesting seed propagation, look around the base of your Aspidistra elatior clumps where you will find the nearly ripe seed pods which look like 1-1.5″ green jawbreakers. These should soon be ready for harvest, and I’ll almost guarantee that you’ll be the only one in the Master Gardener class growing aspidistra from seed.
Years ago, we built our first hypertufa trough that we now keep on our patio near the house. No matter what we planted in it, the plants had a short life expectancy thanks to our cats, especially Pearl, who finds laying in a trough of rocky soil preferable to the soft cat beds that we purchased for her…a trip to the kitty shrink is in her future. After years of trying, we finally found one plant that would survive in the trough without being killed, and that is Teucrium marum…a plant we nicknamed “kitty crack” for its hallucinogenic properties. While Pearl still lays in the trough, often stoned for hours, she is very protective of her kitty crack. This made it all the more surprising when I arrived home the other day to find a stray cat laying in the trough…in an obvious transcendental state of “what, me worry”. Although we don’t know the name of our wide-eyed interloper with a Cheshire-like grin, we’ve nicknamed it Smiley Cyrus.
In some very interesting new research by Kansas State Professor Raymond Cloyd, published in HortScience 45: 1830-1833 (2010), it was discovered that Bounce® original brand fabric softener dryer sheets were quite effective in repelling fungus gnats. As it turns out, the Bounce® sheets that make your clothes smell so good, contain linalool, benzyl acetate, beta-citronellol, and hedione…very effective chemicals against fungus gnats. If you’ve grown plants from seed, you have no doubt run into fungus gnats, which are tiny black flies that live on the surface of moist potting soils. Fungus gnat larvae eat developing seedlings, some even before they emerge from the soil. I recommend sowing your seed, then covering the pot with a Bounce® sheet and securing it with a rubber band. The sheets will allow light and water to pass through while keeping the fungus gnats out. Once the seedlings are large enough, the covers can be removed. Good air movement and keeping the soil surface dry are also very important in controlling fungus gnats.
I recently got a note from Dr. Paul Capiello, director of the Yew Dell Arboretum in Crestwood, Kentucky (just outside Louisville). Paul is looking for a Garden Manager, which is the primary full time staff member dedicated to management of Yew Dell’s gardens, plant collections, plant records, garden staff, and volunteers. For those who don’t know Yew Dell, it was the home of the late plantsman Theodore Klein. Paul would like a candidate with either a 2 or 4 year degree, 3 years of garden supervisory experience, a good handle on plant databases and a passion for plants. This is a great chance to learn and be a part of a great plant collection. Click here for more information.
Last month, I wrote about the controversy at the US National Arboretum, where senior garden staff had decided to discard the azaleas on the Mt. Hamilton hillside at the arboretum. Well, as is often the case, there was more than met the eye and I thank everyone who wrote to share more detailed information about the situation. As it turned out, the arboretum gardens staff had also decided to de-accession (a botanical word for eliminate) several other plant collections including the boxwood collection, the species daylily collection, and the daffodil collection. Bizarrely, these decisions were made without consulting with pertinent stakeholders (a government term for interested parties who don’t work for the government) and even their own USDA researchers, some of whom use the collections in their work.
On the azalea hillside, our friend Don Hyatt of the Azalea Society tells me the azaleas slated for removal are actually not culls from the Glen Dale breeding program, which is a somewhat different situation which I addressed in my last newsletter. Don says the hillside includes both released plants whose tags were lost and more hybrids planted out for evaluation. If so, then the arboretum should work with the Azalea (Rhododendron) Society to evaluate the collections, re-label where possible, and then decide which plants should stay and which should go. I still have the same question…do we really need more than 454 Glen Dale azaleas…of which 312 were selected and named from the original 1000 selections planted on the Arboretum’s hillside plantings? How many of these turned out to be good enough to be widely grown…certainly not 454?. As a plant breeder, I cannot imagine naming more than a handful of truly worthwhile and distinctive plants from 1000 initial selections…certainly not 454 cultivars. I would hope that any further named releases from the hillside would be far more judicious.
Part of the problem with some of the collections targeted for removal is that they draw little interest from large numbers of the visiting gardening public. In the case of each of these collections (other than the azaleas), they are isolated and not incorporated well into with other collections. How many of you who visit the arboretum ever spend time in the boxwood collection? This is actually the National Arboretum’s only NAPCC (similar to the UK National Plant Collections) national collection. I will admit to spending over half a day in the boxwood garden one winter many years ago, and I found it amazing. I’ve been on a crusade for years to get folks to realize there are few evergreen plants better in the woodland garden than boxwoods. Yes, boxwoods are not full sun plants, and are much happier growing among hostas and ferns…and no, they never need pruning. In my opinion, the arboretum would do much better to re-arrange the collections and add other plants to draw visitors into these neglected parts of the garden.
So, why the rush to discard important plant collections? Supposedly, this is a budget decision in response to losing two gardener positions. Interestingly, this happens at the same time as the arboretum announced plans for a new 22-acre Chinese Garden. If you think this is a new problem, think again. When the Arboretum’s world-renown holly breeder, Gene Eisenbeiss passed away in 1997, the Holly Society of America pleaded with the Arboretum to save his unparalleled collection of 400 ilex species. Those pleas fell on deaf ears and the collections were bulldozed. As it turned out, there were those within USDA that felt the world didn’t need another holly. This combined with Gene’s dyslexic plot maps and overgrown collections were enough to justify a major deaccessioning. Like the boxwoods, I spent a good bit of time in the holly collections when Gene was alive. While I’m all for bulldozing culls after a breeding program ends, cooperating with the stakeholders would have undoubtedly saved some valuable germplasm that is now lost. Fortunately, a couple of Gene’s hollies managed to escape before the destruction, including a plant now known as Ilex ‘Cherry Bomb’, which is possibly one of the finest evergreen hollies on the market today. We also grow a compact, hardy form of Ilex chinensis, which still needs to be named, that was salvaged from Gene’s collection.
As the red-headed stepchild of the US Department of Agriculture, the US National Arboretum has long had funding problems. The Congress approves the budget of the USDA, which then doles out portions of that budget to its divisions, which include the arboretum. I remember visiting a couple of years ago to find all the turf at the arboretum nearly knee-high. Some bright bureaucrat had decided that to save money, they would outsource the grass-mowing and only do it on a set schedule, regardless of when the grass actually needed mowing. Public outcry finally brought that disaster to a halt. The recent public response to the proposed plant removal was another great exercise of how our system of government (by the people) is supposed to work. Also, in response to the azalea fiasco, the Friends of the National Arboretum (FONA) announced a $1,000,000 gift to the arboretum to start an endowment to help preserve the collections slated for removal.
To address the recent public relations fiasco, the USDA has also appointed a new director, Dr.
Colien Hefferan. Dr. Hefferan is known in USDA circles as a “fixer”…one who can re-orient the arboretum, study alternative funding sources, and reconnect with both its own researchers and its stakeholders. Prior to her appointment, Dr. Hefferan was director of the USDA’s National Institute of Food and Agriculture (formerly the Cooperative State Education Extension Research Service), and before that, an adjunct assistant professor of behavioral economics at Penn State. To that end, Dr. Hefferan has established a feedback site on the Arboretum’s collection policy that you can find here.
We encourage everyone to offer their comments about the direction of the arboretum.
I also encourage everyone who hasn’t spent time at your National Arboretum to do so when you find yourself in our nations capital.
Finally, if you or your friends have been jumping on the all-native plant bandwagon after reading emotion-wrenching books like Bringing Nature Home, you’ll enjoy this scientific article that cast things in a much different light.
If you entered our Top 25 contest for 2011 (the deadline for entries has passed), you can track the results live here.
There are a number of surprises so far, including the leader of the pack, Iris ‘Red Velvet Elvis’, as well as Paris polyphylla, both new listings for 2011. It’s still early, so we’ll see if “Elvis” can stay at the top with Colocasia ‘Thailand Giant’ nipping at its heels. Other 2011 first time offerings that cracked the Top 25 so far include Helleborus ‘Berry Swirl’ and ‘HGC Pink Frost’ at #8 and #9 respectively, Colocasia ‘Kona Coffee’ at #10, Salvia ‘Madeline’ at #14, Gladiolus ‘Purple Prince’ at #15, Zephyranthes ‘Scarlet Pimpernel’ at #18, Uvularia ‘Jingle Bells’ at #20, and Arisaema serratum var. mayebarae at #25. That’s a lot of newcomers at the top!
Thanks for taking time to read our newsletter and we hope you enjoy the new catalog and website.