Greetings and a belated Happy New Year from Plant Delights. We’ve just added several new plants to the website. Many are very special plants available only in limited quantities, so if you see something that looks interesting to you, don’t wait too long.
So far, it’s been a very mild winter here at Plant Delights and also across much of the country. Although we dipped to 17 degrees F once, that night and one other constitute our only nights below 20 degrees F all winter. A mild winter like this has several interesting effects on garden plants. Plants from warm climates which don’t have a high chill requirement (the number of hours under 40 degrees F required to break dormancy) will often sprout too early, needing only a small window of good weather to start growing. Sprouting early isn’t a problem as long as we don’t have a crazy temperature drop the remainder of the winter. Because of the mild temperatures, we’ve had our best flowering season ever for plants like the winter flowering Iris unguicularis.
One of the other effects is that the lack of winter cold may adversely affect the flowering of plants like peonies that require a high number of chilling hours for good flower development. Fortunately many of these plants requiring high chilling hours won’t sprout early as we see when they get their required cooling needs met early in the winter and are ready to go with only a couple of days of spring warmth. I’m expecting one of our best magnolia seasons in years if nothing crazy happens from now until spring.
Speaking of weather, the big news for gardeners this month is the release of the new official USDA Plant Hardiness Map. Ever since a botched map effort by the late Dr. Marc Cathey in 2003 (known as the American Horticulture Society version), the USDA has been working on a much improved hardiness map update. On August 18, 2004, USDA formed a technical review committee of 23 people including yours truly. The group consisted of nurserymen, crop researchers, foresters, climatologists, and others. The committee had a number of meetings at the USDA headquarters in Maryland and many subsequent meetings by phone.
The details of the map making process was quite fascinating. The first few meetings were spent hashing out what we wanted in the map. Several of us had pushed for a 30-year map, which would more closely echo short term natural temperature fluctuations, and the USDA agreed. Another of my requests to create an a, b, c, and d breakdown for each numbered zone was delayed until the future.
We also wanted a map that would allow more temperature interpolations between weather stations, which would take into account things like lake and mountain effects which were missing in the previous map. The process then progressed to the USDA to gather the data and create the map with their in-house staff. A complication arose when their in-house algorithm specialist was commandeered by the Department of Defense and sent to Afghanistan to run algorithms to locate Osama bin Laden. During this time, the specialist would join us via conference call from a safe place in Afghanistan…I’m not making this up.
After two years, the map was supposedly ready as the committee members gathered in Maryland for the unveiling. We were never privy to exactly what went wrong, but the map we saw showed all of the US getting colder, which was certainly not the case. My best guess is that someone reversed all the data. After this debacle, the map trail went cold for nearly a year, during which time the USDA decided in 2007 not to complete the map in-house, but instead to outsource the project to the PRISM (Parameter-elevation Regressions on Independent Slopes Model) Climate Group at Oregon State.
After PRISM completed their initial map, we were shown a draft map via phone conference. The rest of the year was spent going back and forth about areas which the review team felt were not zoned correctly. During this time, more data sites were added to those regions of concern, either from Canadian, Mexican, or military data. Finally in April 2008, the technical review team finished their work and the map was back in the lap of the USDA for publication. The subsequent 3 years and 9 months were spent by USDA trying to figure out what colors to make the zones and then finding a website that could host the map without crashing like their previously launched food pyramid…I’m not making this up. Whoever said that the Federal Government moves slowly was spot on…hence the reason the most recent climatic data in the map is 6 years old.
So, let’s talk about the map. On the map website, there is a static version and an interactive version. I like the interactive map the best. Plant Delights is located at zip code 27603, so enter our zip code and this will bring up the map where we are located. You will notice that most of the area is olive (Zone 7b), with a few blocks of light orange (Zone 8a) nearby. Everywhere you click on this map, you can see the longitude and latitude, along with the hardiness zone and the average minimum winter temperature for the 30 year period of 1976-2005. By clicking around the map where we are located, you will see that all areas inside the orange blocks have an average minium winter temperature above 10 degrees F, making them Zone 8a. If you click anywhere that has an olive color, you are now in Zone 7b and the average minimum winter temperature will be below 10 degrees F. With these maps, you can pick out the warm spot in a neighborhood before purchasing your new house.
I hope you’ll enjoy the new map, and would like to thank everyone with the Department of Agriculture and all the other committee members for their hard work on this project. If you’d like to read more about the history of the hardiness maps, check out our online article.
While we’re talking about the USDA, I want to once again mention one of their divisions, the US National Arboretum, which became embroiled in a bit of controversy last year when a few members of the Arboretum staff decided to eliminate several of their significant plant collections. While public outcry salvaged those collections, the Arboretum is now seeking input from the public about the direction that it should take in the future. Although it’s not very well written as a questionnaire, I hope you’ll take time to complete the following survey.
In other plant news, the Perennial Plant Association has announced that Polygonatum odoratum ‘Variegatum’ has been selected as the 2013 Perennial Plant of the Year…congratulations! Here you can find the list of current and past winners of this prestigious award.
It’s quite exciting when a plant you find in the wild turns out to be a new species, especially in your own state. You can imagine our excitement when we heard last month of the publication of a new wild ginger, Asarum sorriei…unfortunately published using the antiquated genus name, Hexastylis. In 1999, I was botanizing in Moore County, NC and stopped at a site that consisted of a low area with sarracenia (pitcher plants) and zigadenus (death camash). The low area quickly transitioned into a drier area with amsonia…all within a few hundred feet. It was a fascinating site, but the one plant that seemed most out of place was an asarum that grew in sphagnum moss among the pitcher plants in full sun. The flowers and foliage were quite similar to Asarum minor, but the habitat was quite un-minor like. It seemed obvious that this find was either a new species or at least an ecotypical variant of Asarum minor. Shortly thereafter, I passed along the info to Alan Weakley, author of the “Flora of the Carolinas and Virginia.” According to the publication, others also noticed the plant around 2004, and then finally last month the ginger was christened as a new species, Asarum sorriei. We look forward to getting this into cultivation as soon as possible. You can read much more about this in the scientific publication “Phytoneuron.”
We are very pleased to announce that the Hardy Plant Society, based in Pennsylvania, is planning a road trip to see gardens in the Raleigh area this spring, including Plant Delights. This will be a group of very serious plant nerds, so if you’d like to join the fun, read on. The 4-day tour departs from Downingtown, PA with a stop at the Lewis B. Ginter Botanical Garden in Richmond VA for lunch and a garden tour. Then on to Raleigh where you will visit a number of private gardens in addition to the JC Raulston Arboretum. Included is a tour of Plant Delights Nursery plus the chance to shop for special finds for your own garden. Cost: $685 (double occupancy, $240 additional for single supplement) includes motor coach transportation, driver tip, all breakfasts and lunches, admission to the Lewis B. Ginter Botanical Garden, Wine & Cheese social, and room. You will be staying at the downtown Raleigh Sheraton, a great location for walking to nearby restaurants for evening meals. The trip registration form will be posted on the HPS website, www.hardyplant.org. Spaces are limited and on a first-come basis. For any questions or a form, contact Janice Thomas: firstname.lastname@example.org or 610-458-9794.
Finally, in the “in case you missed it” file this month, researchers from UCLA have identified how a component of the hardy raisin tree (Hovenia dulcis), called dihydromyricentin works as an anti-hangover treatment by counteracting acute alcohol intoxication. Research showed that the dihydromyricetin blocked the action of alcohol on the brain neurons, which also reduced the desire to drink…human clinical trials are next. This could do wonders for the sale of the formerly obscure Hovenia tree.
Remember that the deadline to enter our Top 25 contest is nearly here. If you’d like the chance to win a $250 gift certificate to Plant Delights, be sure to submit your entry here.
We’ve had an order snafu and one of our orders only has a new customer’s name associated with it, John F. Wichter III. If this is you, please contact us with your shipping address so we can send you your order. Thanks!
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