October, 2009 Archives

OK, we’re not Vermont, but if you squint your eyes on a gloomy day in Western Washington, you can find color out there besides green. Anyway, with some artistic contributions to the garden, you can certainly make the best of it.

witch hazel

Witch hazel (Hamamelis x intermedia ‘Jelena’)

cherry leaves

Cherry leaves

garden cherry trees

Eastern cherry trees in the garden

Salmonberry

Salmonberry (Rubus spectabilis)

  

 

himalayan blackberry

Himalayan blackberry (Rubus discolor) 

red dahlia

Red dahlias

 

pyrocanthaPyracantha koidzumii ‘Victory’

Japanese blood grassJapanese blood grass (Imperata cylindrica ‘Red Baron)

maple leaf

Big leaf maple (Acer macrophylla)Campanula and maple leaves

Campanula and Japanese maple leaves

Woodland Rain Garden

 

 

 

 

 

 

 

This will be my first winter in WA in two years, and already my instinctive rainfall calculations are off.  My carefully planted woodland garden, intended in part to provide a buffer zone to capture driveway runoff before it reached house, has instead become a minature Mississippi. 

A mature cedar tree under which this area was planted  justified my refusing to add soil to elevate this part of the yard above the side yard that runs to the south side of the house. Once the front yard was done and the roots partly compacted on that side from the excavator back in June, I figured it best to leave the poor tree alone. Cedars have a network of shallow roots that are easily damaged, and I was concerned that the weight of a few more inches of sil might suffocate them.  Instead, I placed about two inches of much lighter mulched wood chips and horse manture  over the area and edged it with a low rock wall to hold the material back off of the side yard, which was about six inches lower.  These few inches, I felt, would absorb any surface runoff.

frontlawn2 6-09

Front yard with excavator, June 2009

However, even before full soil saturation was acheived, a hard overnight rainfall October 17 was enough to flood my little garden. What went wrong?  The amount of water collected over about 70 feet of open driveway at a 0.5% gradient combined with soil compaction and a lack of vegetation probably combined to overwhelm the buffering capacity of my short strip of mulch.  Although I had planted a lace-cap hydrangea, two Pieres ‘Mountain Fireand a few sword ferns, it was not enough to slow the surface flow.  Subsequently, both the volume and velocity of the water was sufficient carve a drainage through the rock wall and down into the back  yard where it disappeared into the septic drainfield.

runoff through side yardAs I stalked about the yard in the pouring rain with my camera, I pondered my options. I had been considering installing a small reflecting pond surrounded by vegetation in the path of the current flood. That, however, would not be sufficient to absorb the flow.  Digging out a small retention pond would be  infeasible if I want to protect the cedar tree. I tend to avoid berms as a way of delaying the inevitable (kind of like pushing rocks uphill, really), so I ruled out shunting the water further along the drive and into woods. Filling the area with vegetation will probably be the only way to baffle the flow and keep it stationary long enough to sink into the ground before it reaches the back yard and drainfield.  I need a rain garden.

According to a University of Rhode Island website on sustainable landscaping (raingarden.htm),  a rain garden “is a natural or dug shallow depression designed to capture and soak up stormwater runoff from your roof or other impervious areas around your home like driveways, walkways, and even compacted lawn areas…The rain garden is planted with suitable trees, shrubs, flowers, and other plants allowing runoff to soak into the ground and protect water quality.” 

Planting dense grasses or multi-stemmed, creeping vegetation should protect the surface from channelization and the give the water time to soak in.  My observations the morning after the heavy rainfall confirmed that the soil quickly absorbed the water after the rain ceased, despite the relatively high clay content.  This may change as winter progresses and the soil reaches saturation, but experimentation with other temporary methods of water baffling, such as pieces of wood, may prove that slowing the flow will be enough.  Some calucations of slope, anticipated runoff volume, and soil absorption capacity based upon composition will aid my work if I feel like playing engineer for a day.  Things are far too wet right now for planting, but I’m already designing a plan for spring.

I think it’s the combination of problem-solving, geology, engineering, botany, and creativity that makes this enterprise sooo much more fun than my previous paying job!

The Rain Garden

  • October 23rd, 2009
  • Posted in Landscaping
  • Comments Off on The Rain Garden

 

I came up with the idea of a winter vegetable garden while nosing about in the old barn where my father had dumped a random assortment of junk, including a box of books from which I’d gradually been extracting all of the most interesting delicacies. I had figured it was time to pack up the rest to donate to the library when I came across a little paperback at the bottom entitled WINTER GARDENING IN THE MARITIME NORTHWEST: COOL SEASON CROPS FOR THE YEAR-ROUND GARDENER by Binda Colebrook (Rev. ed. Seattle: Sasquatch Books, 1998). I read it over the period of a few days and was inspired. 

PICT4787

The barn - a landscaping tale of its own and the site of the winter garden

 To date, I had always associated ‘winter’ and ‘garden’ with a drab mess of slimy plants moldering in the garden by about the beginning of October.  At that point, I would quit weeding and more or less give up hope.  But this book bespoke confidently of the possibility of tasty greens, crispy kales, and tangy beets. It even sounded remotely…cozy: growing and then picking greens in the dead of winter to feed the family fresh salads.  Determined to do it right, I took the rare step of planning my purchases in considerable detail and – not to skimp on just any seeds – I went to an online seed vendor (Nichols Garden Nursery in Salem OR – a most excellent choice for price, selection, and timeliness) and purchased one package each of the following:

CABBAGE – EARLY JERSEY WAKFIELD Heirloom

CORN SALAD – MACHOLONG

KALE – RED RUSSIAN Heirloom

ONION – EVERGREEN HARDY WHITE BUNCHING

RADISH – RELISH CROSS HYBRID

Carefully following the instructions in the book, I then selected the ideal site:  a spot protected from north winds, sunny in the morning, and not in a low area where the cool night air might freeze it.  The solution was a weedy area in front of  the barn-turned-studio where I laid out a simple 10′ x 6′ frame of untreated 2×12’s and added a about a yard of  5-way soil mix and rotted manure from a generous horse owner.  

winter garden

The winter garden as of 10/4/09

The seeds arrive in the mail around August 20,  and I had them in the ground by the second week of September. By October 4, they were up and growing strong – the largest leaves in the photo are the radishes, which got a quick start followed by the kale, corn salad, and beets.  In fact, I was rather surprised by the rapid germination, which may have been the result of lingering summer warmth and occasional light rainfall which produced a crop faster than I was able to get in early June (see ‘Yard as Garden’).

This would be a happy tale except that out of the blue, hoofed disaster struck. The goats, with whom I have been fighting a running battle to keep fenced out the yard, escaped as they often do and (sob!) swept through my garden.  The biggest and showiest got their attention, leaving me without radish or kale, unless a miracle happens and these tender annuals can regrow their missing leaves. Apparently goats have a knack for nibbling the tops of things without the tearing motion used by horses and cows that would otherwise uproot the entire plant. Thus, a goat-grazed plant usually retains a skeletal frame of stems without any leaves.  Of course, there is always reseeding and the hope of another quick germination before the frost. That same day, they also razed my new Virginia creeper in a gallon pot, again taking only the leaves.  The warnings of a poison ivy -like rash were unheeded by the goats, who survived with no apparent ill effects.  

In the aftermath of my loss,  I spent the better part of a day and a half repairing the fences necessary to contain the hoofed menaces, but for now must face the startling gaps in my winter garden.

My next challenge will be the frost, which will be coming soon I think. Saturday night was clear and a cold 38 degrees. Realizing the challenge to my carpentry skills, I’m procrastinating for a while before constructing a cold frame of wood and plastic. In the meantime, I’m keeping the goats occupied consuming blackberry leaves and their most favorite food, Douglas fir branches.

Winter Vegetable Garden

Soils Management

moss ground cover

The situation that I face here is somewhat unique in that the property immediately surrounding the house is forested. I am not, therefore, dealing with the concerns of imported, compacted soils that usually inform the decisions of the gardener on the urban lot. Rather, I am surrounded by disturbed native soils that have been cleared of native vegetation and allowed to grow all manner of invasives.

 

My decisions are thus: chop up the soil and add amendments to create a nice, smooth planting surface, or remove undesired species by hand and disturb only the immediate area necessary for planting.

 

As an ecologist, I identify strongly with the latter approach, particularly in areas where the soils have been allowed to settle and form a rich humus top layer. In many instances, the predominant ground cover is moss, through which small herbaceous plants grow protected from the damage of raindrops and the drying effects of the summer drought.

 

 

In other places, a dense layer of fir needles creates thin but effective mulch nurturing a community of microorganisms that keep the underlying soil moist and fertile. Often while I am installing plants near a natural border, I will take a scoop or two of the topsoil from an undisturbed area and place it in the hole in lieu of potting mixture. 

 

 

 

Removing non-native species, in particular Himalayan blackberry, while preserving forest soil integrity has become a time-consuming process, but it not without its rewards. In fact, I take a curious pleasure in wading into a thicket higher than my head armed only with gloves and bypass shears and clipping the canes down to the ground. Perhaps it is part of the simian nature to want to clip and pull things, much like chimps grooming each other’s fur. Whereas lawnmowing or watering are chores that quickly tax my admittedly limited patience, I can stand for hours complacently chopping briars.

 

The results in the areas where I have implemented this practice have been good. Leafy forbs such fringecup (Tellima grandiflora) and youth-on-age (Tolmiea menziesii) have emerged from areas once dominated by dense thickets of briars. Ferns appear to enjoy the light as well. Furthermore, as I trim, I do a plant survey of what lies beneath so that I can easily avoid anything that I want to preserve. Based upon my personal experience as a biologist, I recognize that the plant diversity here is quite low, and getting lower as more invasives enter areas that have been previously disturbed. There are, for instance, very few populations of fringecup left here, or of the few small clusters of coral root (Corallorhiza maculata) that I have located here. Finding and preserving them will be a big part of my personal conservation plan for the property.

 mushroom

Goats are another option, but these cute little cud chewers tend to prefer already open areas, perhaps a function of their innate desire to avoid predation in dense vegetation. They will not wade into a brush and blackberry canes unless constricted only to that habitat. Subsequently, I encounter them each day in their half-acre pen contentedly chewing their cud in a sunny dust wallow of their own creation while the briars threaten to take over the garden at the other end.

 

I will be the first to admit that this approach to soil conservation is slow, and as I do my six-month progress review with my camera, I feel as though I have achieved very little. In many areas around the house, the weeds still encroach, the areas I have landscaped have not reached maturity, or some of the plants have not met expectations and will need to be moved.  Meanwhile, I struggle to assimilate the principals of design and apply them to my unplanned, off-the-cuff ideas. In many ways, I am more comfortable when I step off into the back 20 leaving behind the world of the manipulated landscape and entering the forest ecosystem that I know and love.

Soil Management