It is almost midsummer at least astronomically. On Wednesday of this week the season is in full swing with the passing of the summer solstice whereby the northern hemisphere is closest to the sun and we experience the longest day. That’s right, tomorrow is the summer solstice! Never mind that we are going to be experiencing 92+ degree heat. Wow, where has the time gone? The normal tradition of a solstice bonfire may not be the best idea this year even if you believe the hype and it may be the last summer solstice ever!
My blog posts, as usual, have been few and far between as the weather has continually improved and I spend more time outdoors either in my garden, in the field doing ecological evaluation and survey work or in other people’s yards assisting them with their projects. This spring I spent some time working on the walkway garden that Billy, my project collaborator from Cascade Designs Inc., and I installed last fall. Although bloom timing has been skewed by the very mild winter and abnormally warm early spring things are starting to fill in nicely.
Prior to the new walkway the entrance to our recently purchased home consisted of an “L-shaped” broken brick walkway with no aesthetic appeal and very little function. My goal was to provide a welcoming entrance with sensory appeal for myself and my guests, both visual and olfactory (oh, and to eliminate some of the ecologically functionless lawn that came with the front yard, much to my lawn-loving husband’s chagrin).
This was my first foray into this kind of design as my previous gardens have been more for the “birds and bees” and for this reason they sometimes lacked defining detail for the “human” eye. Being an ecologist and not a landscape architect I attempted to take into consideration common design principles including shape, flow, function, line, texture and color while still keeping the ecological function of the project a major component. This actually meant that I allowed myself to stray from my native plant philosophy to some extent and I also allowed myself to use cultivars (go figure…). However, in many cases I used plant material I “sourced” from my other growing areas so many of the preferable natives appear again and again within the overall palette.
I used boulders including a standing stone or lithe to help define the overall shape and provide interest.
Also, during installation of the walkway and the bench circle I was looking for something different. Billy came up with the idea of using a boulder to encroach into the stone walkway as an interest feature. He meticulously cut the circle stones to fit around the boulder. Loved it!
From the sensory standpoint the walkway is surrounded by a heady mix of sensual smelling plants including lavender, thyme, marjoram, sage, evening primrose, roses and lilac. For the birds and bees I made extensive use of some of my favorites including Penstemon digitalis ‘husker red'(Beardstongue)
Liatris spicata (Blazing Star); Aruncus aethusifolius (Goat’s Beard); Echinacea purpurea (Purple Coneflower); Rudbecki hirta (Black Eyed Susan) and its cultivars ‘indian summer’ and ‘angustifolia’;
Asclepias tuberosa (butterfly weed); Aslepias syriaca (Common milkweed); Aster Novae Angliae (New England Aster); Aster Novi Belgii (New York Aster); Salvia nemerosa (Sage)
including the varieties ‘may night,’ ‘indigo spires;’ and multiple varieties of Salvia offinalis including ‘tricolor.’ The larger wood specimens were picked for their form and shape including the weeping cherry, weeping Norway spruce and holly.
These shrubs repeat the triangular design of the boulders embedded within the garden.
On a warm evening it is wonderful to sit in the rocker on the front porch and enjoy the scent. Also, the front yard wildlife do not seem to have any complaints either, though, the chipmunk’s recent habit of dining on the standing stone is somewhat tantalizing for the neighborhood Cooper’s Hawk.
But, being a gardener I am already planning on what needs to be moved and to where, and of course I am already onto my next project which is the expansion of my back butterfly garden along with design and integration of a new sitting patio into it. Gotta love the gardening bug!
At least we can say the March came in like a lion… However, I am still finding it very hard to believe that the worst of our New England winter is over. I know what you are going to say, “What winter?” In my lifetime I cannot remember having this little snow and such warm sunny days. The lack of snow this winter, however, has definitely put a crimp in my winter tracking activities. It has also provided a little bit more of a challenge, and well, challenge can be fun! That said I am looking forward to some winter tracking this weekend!
A couple of weeks ago I went on a “varmint” hunt. Given the lack of snow and some spring “melt,” if you can call it that, I figured I had a fairly good chance of finding sign of some ground-burrowing critters. I started by looking under hanging garden plants and turning over boards or other fixed objects in our back yard. Bingo!
What did I find? Shrews! Shrews have been called a lot of things but I think that Sudbury Valley Trustees described them best as “tiny tigers.” They have sharp, spike-like teeth and as the smallest mammal no bigger than our thumb (2 to 4 inches), these creatures spend most of their time running around in above-surface tunnels hunting a variety of bugs and earthworms. They will also eat other shrews, mice, salamanders, snakes and have even been known to kill small rabbits! They may also eat mast, seeds or eggs. Shrews will even cover their “kill” with grass or leaves for a later meal (just like my cats try to do with their food bowls). The shrew does not have grinding teeth and the tips of their teeth have a yellowish color when living, at least in New England.
Their size often allows them to escape our attention even though they are fairly common. They, like other ground-dwelling varmints such as mice, voles and moles are considerably active throughout the winter.
How do you know if you have shrews, rather than one of the other rodents? That is, other than seeing them. Shrews, being the smallest mammal also make the smallest hole (1 inch or less). They do not make meandering ridges just under the surface of the ground under snow like voles or moles or create 6 inch round entrance mounds like moles. If I were to catch one, I would find that each front foot of a shrew has 5 toes, where a mouse would only have 4 front toes.
Behaviorally, shrews and voles are much alike. They both make tunnels or pathways in the grass and these runways can be difficult to discern from each other, especially since they will use another animals’ highway complex.
The difference is often the size. Shrew pathways which can be located in grass or leaf litter are usually less than an inch in diameter, whereas vole tunnels are slightly larger and usually only in grass. They also landscape their tunnels differently. Voles nip or cut the vegetation on the sides and bottom of their tunnels, sometimes leaving only bare earth. Shrews are less fastidious and the grass will often just be plowed to the side.
Interestingly, shrews are known to have a putrid, musky odor that makes them unpalatable to predators, so usually the only time they are found is after they have met their fate and been abandoned. BTW this is how I knew I had a good chance of finding them in my back yard… Either the fox or a neighborhood cat had clued me in. It is generally believed that the odor is a reproductive marker as it appears stronger during mating. Some shrews that we will find here in Massachusetts include the short-tailed shrew (Blarina brevicauda), least shrew (Cryptotis parva) and the masked shrew (Sorex cinereus).
Shrews are unusual among mammals in a number of respects. They are one of only two land mammals known to echolocate (the other is a mammal from Madagascar that resembles a hedgehog). Unlike most mammals, however, some species of shrew are venomous. Shrew venom is not conducted into the wound by fangs, but by grooves in the teeth. The venom contains various compounds, and the contents of the venom glands of the American short-tailed shrew are sufficient to kill 200 mice if delivered by intravenous injection. Don’t worry though, it won’t kill a human, but it may cause some swelling. Always best not to handle a live shrew without some protection. Just in case you were thinking about going homicidal on your backyard shrews, think again. Like every other living thing on the planet there is always hidden utility. Shrew venom has potential medical use, as one chemical extracted from shrew venom has been demonstrated to show potential for the treatment of blood pressure. Another compound may be useful in the treatment of some neuromuscular diseases and migraines. The saliva of the Northern Short-tailed Shrew (Blarina brevicauda) contains the peptide soricidin and has accordingly been studied for use in treating ovarian cancer. Another interesting factoid…Amazingly, shrews hold nearly 10% of their mass in their brain, which is the highest brain to body mass ratio of all animals (humans included!)
Now moles,on the other hand, are just plain funky! The most common foods moles eat include earthworms, insect larva and other soil arthropods. They also eat grubs and plant bulbs but not as voraciously as the vole does. Most mole damage is caused by tunneling in our monotypic lawn, and not by eating plants. Go Moles!!! The most commonly encountered moles are the eastern mole, which causes most of the damage found in yards, and the star-nosed mole, which is mostly found digging tunnels in swampy areas and at deeper levels than the eastern mole. Mole feeding tunnels are usually 2 to 3 inches below the surface.
Okay, right about now you are thinking that I am absolutely insane because I am happy that I have rodents! Probably true. If they were in my house I would be at Agway right now looking at all kinds of unique ways to remove them from my abode. But what their presence in my yard, and especially in my garden, tells me is that my organic gardening practices are working. I attempt to provide a variety of plants for a variety of native insects. I do not use chemicals or fertilizer formulations other than compost tea or a nature-based organic nutrient source. I leave my leaves and plant structure throughout the winter to provide overwintering area and a food source for the critters. The presence of the shrew means that my garden is beginning to function as a miniature ecosystem with a natural balance of both predator and prey, which on a cold snowy day makes me smile.
If you have read my previous posts, then you know of my personal war with one of several invasive and non-native plant or animal species in my backyard here in Chelmsford. I would like to think that I am not alone in this endeavor, either locally or regionally. So far I am not disappointed by my on-line excursions.
If you are interested in gardening for wildlife, butterfly gardens, plant or wildlife ecology or are just beginning to develop an inkling of interest in this topic I strongly recommend you take advantage of a rare opportunity to hear one of my top-list authors and a well respected scientist, Doug Tallamy (Bringing Nature Home: How You Can Sustain Wildlife with Native Plants)lecture this Wednesday night (October 5, 2011) in Carlisle, MA. The event is being sponsored by the Carlisle Conservation Foundation, Susan Zielinski Natural Science Fund, and Carlisle Conservation Commission and will begin at 7 pm at Corey Auditorium in the Carlisle Public School.
As many gardeners undoubtedly do, I use my garden as an expression of what is attractive to me as an individual. Also, as I have a strong interest in nature and ecology I seek to do the right thing while expressing myself in this artistic way. I want what I put in my garden to function in sync with the natural environment. Mr. Tallamy who is also a renowned entomologist (insect ecologist) at University of Delaware provides abundant scientific documentation to support that alien plant introductions generally do not have a productive ecological relationship with our environment. This is because they often have different characteristics such as leaf chemistry, time to maturity, or time to bud and flower. What this means is even though they are phisically present in our natural environment, they are not contributing or giving back energy to the system the way a native plant would (just taking it away).
We, as gardeners, do have a choice. Now, more than ever before native alternatives to invasive horticultural varieties can be found. However, if you are not familiar with the horticulture trade or with these alternatives, it is easy to be overwhelmed and led in the wrong direction by a well-intentioned nursery worker, or even, a less than well-meaning individual who just wants to make money.
For example, not all native plants are created equal. Some so-called native plants are actually naturalized alien plants from other countries.
Some nurseries will push these plants as “native” or alternatives to invasive plants. Some plants are cultivar varieties (genetically altered) of our natives which may not possess identical or even similar traits to the native variety, depending upon what it was “crossed” with.
These plants will often be touted in their descriptions as “pest tolerant,” “a caterpillar may eat the foliage occasionally,” “deer resistant,” “disease free,” “mostly allergy free,” good for naturalizing, etc. What a description like this tells me is that the plant does not possess a substantial ecological benefit and it is not contributing much in terms of food to native insects, which are the base of our regional food chain. Any of the descriptions I listed above would be a BIG “red flag” in my book.
As an example, a lot of the statements above will often be found if you search for traits of the common butterfly bush (Buddleia davidii or Buddleia x weyeriana). Now, you are saying wait a minute, isn’t the butterfly bush good because it attracts butterflies? Well let me, and some of my favorite online sources, enlighten you. The butterfly bush is a butterfly magnet and I can often find many butterflies on it during the summer season where they seek the very abundant and nectar-rich flowers which bloom almost constantly from spring to fall. Tallamy’s research shows “not one species of butterfly in North America can use Buddleia as a larval host plant.” In particular, a large number of butterfly species are very plant-specific and will only use 1 or 2 plant types to deposit their eggs and provide food for their hatching larvae (think milkweed and the monarch butterfly folks). Without the presence of a particular plant, you cannot have a particular butterfly. Therefore, without larval host plants you cannot have any butterflies. Taken to the next logical step, if everyone is following horticulture and nursery recommendations to create a butterfly garden with the butterfly bush as its anchor plant, butterfly diversity (number and variety of butterfly species) will undoubtedly continue to decline as we raze additional natural land to build even larger suburban homes and replace these sites with sterile turf lawns.
Now, here’s another little tidbit for you. The butterfly bush is considered invasive in over 25 North American states, including Massachusetts, Connecticut and Rhode Island – that is if you go by the U.S. Department of Agriculture Plants Database. I can honestly say that I personally have not had any experience with this plant’s invasive tendencies but I have heard of other wetland scientists that have. It is not currently listed on our Massachusetts Prohibited Plant list and it also has not been evaluated (as far as I know) for noxious tendencies by the Massachusetts Invasive Plant Advisory Group. Other organizations, including the National Park Service, Audubon, and other state and governmental organizations have it on their “Invasive Watch List,” or have outright banned the sale of the plant. It is considered prolifically invasive in Zones 6 and 7 (Mid-Atlantic States such as PA and VA) as well as the Northwest. It is on the “Most Invasive” species list of the Pacific Northwest Exotic Pest Plant Council. In this region it is extremely invasive in disturbed natural areas such as burn sites and along large streams such as the Willamette River. It has been a huge problem in England, where it is considered one of the top 20 noxious weeds, infesting large tracts of disturbed land 50 years after it was introduced in those areas.
You see every plant has a niche or a microhabitat which it prefers. I for one am not completely knowledgeable about this plant and what its preferred microhabitat may look like (I am NOT a botanist). But I can hazard some broad assumptions (thinking aloud folks…don’t read in more than that) based upon its noxious nature elsewhere.
For example it appears to respond well to fluctuating wet environments where it spreads predominantly by very abundant seedlings. It likes riparian corridors and floodplains, especially such sites that have experienced some level of disturbance. The fact that it likes burn sites AND wet areas could reveal an interesting relationship with nutrient cycling on low pH sites (cold, wet or acidic sites) or the timing of availability of elements critical for plant growth following a disturbance (Nitrogen or Phosphorus). For example inorganic Nitrogen can be made available through bacterial fixation following a burn event and is often considered a valuable post-fire nutrient source. Another byproduct of fire to consider might be potash (Potassium in a water-soluble form) The time it took to infest U.K. sites makes me wonder how long the seeds remain viable in the seed bank once they are deposited there?
Research on the Buddleia problem in the U.K. by Oregon State University has revealed that seeds from the plant require a long time to develop and release from the plant. Similarly, U.K. researchers have discovered that flower heads from a previous summer do not release seed until dry weather occurs the following spring. This could be very useful information. It is also possible that climate fluctuations or microclimate condition is sigificant. For example, does PA or VA normally have a dry spring (did we in MA have a dry spring in 2010)? In addition, practical application of this info suggests that pruning all of the spent blossoms from the butterfly bushes in the fall prior to full development of the seed could potentially limit release of the seed to native environments (possibly a best management practice?). Well at this point I am starting to ramble and very loosely hypothesizing with nothing to back it up. Needless to say, I have begun removing the butterfly bush from my gardens.
I think that Carole Sevilla-Brown in her Ecosystem Gardening Blog says it best. We have been down this road before with many of our currently-listed and most noxious invasive plants. She highlights the Bradford pear, purple loosestrife, and multi-flora rose. These are just a drop in the proverbial plant bucket. It is pretty clear that the Horticulture Trade has not learned from past mistakes. The industry’s on-going attempt to create a sterile form of butterfly bush is like déjà vu of the failed attempts at purple loosestrife sterility. If we don’t learn from our past mistakes we will be doomed to repeat them over, and over, and over again. Gee, even the mouse in the maze learns from repetition and will eventually find the cheese…
Anyway, if you have an interest and are able to find time to attend Tallamy’s lecture in Carlisle, I hope to see you there.