Sunday, 9 June 2013

What constitutes a low maintenance garden?

After:  Updated colourful garden, 2 months after installation
We have never been asked to design a "high maintenance garden" yet;  everyone wants a "low maintenance garden."  So what is a low maintenance garden?

Before:  Original garden with lawn
First, this depends on the maintainers.  Is the homeowner someone who enjoys spending some zen time once a week pushing around a lawnmower?  Or perhaps the homeowner enjoys mindless weeding and deadheading while listening to books on tapes.  Alternately, a hired hand could be the only person ever to set foot in the garden.  These factors need to be considered when designing a garden.

Second, for a garden to be low maintenance, it must be designed for the environment.  Plants are chosen according to soil conditions, the amount of sun available, the drainage patterns, and the traffic patterns in and around the garden.

The garden pictured here is one that has evolved over its 35 years.   The original garden was a developer's special:  Azaleas and Junipers.  The homeowners introduced various favourite plants over the years: sometimes choices were appropriate;  other times not.    Live and learn.  

The children became adults and moved out.  Then came grandchildren, so low maintenance evolved into lawn.  Lawn is easy to cut, and somewhere for the kids to play.  The grandchildren grew up, and the owners could no longer mow the lawn.  Now they were dependent on the kindness of neighbours to keep the entrance welcoming.  So the next evolution was introduced.

The advantage is that now the owners are very familiar with their garden:  the soil conditions, the amount of sun available, the drainage patterns, and the traffic patterns in and around the garden.  With all of this information, and a better sense of plants available, the garden is now a colourful, low maintenance garden.

Sunday, 2 June 2013

Plants grow, so plan ahead

Thuja plicata (RedCedar) hedge
This photo portrays an excellent example of a short sighted landscape design.  This RedCedar hedge is planted 1'-0" from the public sidewalk, and on 3'-0" centres, or 3'-0" apart.  There is not a hedging shrub in cultivation that should be planted 1'-0" from the sidewalk, because every plant needs space to grow.  However, RedCedars in particular need a lot of space.

For instance, RedCedars grow in the wild to 170-250' (50-70 meters). One of the features of a red cedar is its buttressed trunk which can be 6'-0" in diameter at maturity.  Although these cedars will never reach those dimensions, they will easily and quickly form a hedge 6'-0" deep and 10'-0" high.

My guess is the homeowner requested an inexpensive, fast growing hedge for privacy. The RedCedar hedge will definitely provide privacy for the homeowner quickly, and it is the least expensive of hedging shrubs.  But the hedge will not stop growing once it has provided the privacy;  the hedge will continue growing for years, and for years the homeowner will have to pay to have this hedge trimmed.

Hedges that are repeatedly pruned hard become stressed.
Hedges that grow beyond their required height are
expensive to remove.
All formal hedges have to be trimmed regularly to maintain shape, width and height.  But when a hedge is planted so close to a public sidewalk, the public's right of way becomes an issue.  There are also often municipal issues of not obstructing an area within 2'-0" of a public sidewalk, and in this case, site lines at an intersection.

Even with pruning, the trees in this hedge will continue to grow in girth, and the trunks and roots of the RedCedars will eventually lift the public sidewalk, making it uneven.  The solution to levelling the sidewalk may be to remove the concrete, cut all the roots of the hedge, and re-pour the sidewalk.  This will be a solution for the sidewalk, but not a solution for the hedge.

A better solution is to choose an appropriate hedging material during the design process. The appropriate hedging material may be more expensive initially, but will be cost effective during its lifetime.

Thursday, 30 May 2013

Analyzing your site

Here is a good example of the importance of analyzing the conditions of a site before detemining a design.  This apartment building had a badly designed patio area.  The area has no shade from about 10 AM until evening.  On the other side of the fence is the lane and two apartment buildings.  Across the lawn, about 40' away, is the south side of a ten storey concrete apartment building.  Directly facing this patio at ground level are large windowed bedrooms of a suite, without privacy screening.  In fact, we were the only people who ever sat in the two chairs provided on the patio.


As with many apartment buildings, the garden area is actually a rooftop garden, over the parkade. Unfortunately, the original landscape design allowed for very little soil, and the depth of the soil is 4"- 7".  The design did not seem to have included drainage.  Most of the garden is a bog.

The surface of the patio is mud covered with a thin layer of non-compactible gravel. The entrance to the patio is either across the boggy lawn, or slaloming through the half barrels sunk into the patio surface.  The arbour built over the patio remains empty because there is nowhere to grow vines around the base of the arbour posts.

In summary, we have a shadeless, full sun, uneven surfaced, viewless patio.  Attempts have been made to green the patio with herbs and Roses and Hypericum:  random plantings in random containers.

Install Day, April 2012
We, The Cultivated Gardeners, were asked to design an alternative to the unused patio.  

Our first consideration was compiling a list of full sun bog plants.  Secondly, we removed the rocks and mud, and replaced that with healthy, organic soil.  Carpenters fixing the fence had already removed the arbour.  Then we created a design using complementary plants, and focusing on textures, repetition, and all season interest.  We also threw in some blueberries and garlic, and a tomato plant grew from the compost in the soil mix.

April 2013

Ironically, within months of us installing this new garden, the strata owners wanted a seating area to enjoy their beautiful garden.

Wednesday, 8 May 2013

Rain Gardens vs. Swales

I am researching rain gardens for a new garden design.  The clients live in Richmond, and have a high water table--inches below the surface of their lawn.  They have asked me to design a garden with a rain garden feature, that would tie into a drain.

I have been pondering how to design a rain garden when water frequently sits close to the surface.  If there is no drain, the rain garden will be a pond for most of the winter months.  If there is a drain, where should it be located to be effective?

Rain Garden
Part of my research has been to define the term rain garden.  In fact, a rain garden is a planted garden that holds water for, ideally, no more than 48 hours.  A rain garden may look no different than the rest of the garden, but the soil could be boggy at rainy times of the year.
Dry River Bed

Construction of bioswales on
Blenheim Street, Vancouver
The photographs my clients sent me of their favourite gardens are in fact dry river beds. Dry river beds are not planted, and they may or may not have a lining.  If a dry river bed has a lining, it is designed to move water.  If a dry river bed does not have a lining, it is designed to absorb water, and may have a French drain beneath, which moves water.  A dry river bed should be located at a lower grade than the rest of the garden.

A swale slows the pace of water down a slope. In Vancouver, there are a series of swales on Blenheim street.  Before these were installed, rainfall was channeled down the hill and into drains strategically placed by the road side. Now, the water is channeled into curb breaks, and collects in the swale with much of the water absorbing into the ground.  If too much water is channeled through the curb break at one time, a catch basin at the end of the swale stops the water from flowing over the sidewalk and back onto the street.  The catch basin is higher than the bottom of the swale.  If the catch basin was placed at the bottom of the swale, water would simply collect in that and be swept into the ocean.  The bottom of the swale should be designed with pervious soils to allow water to be absorbed into the ground.

Saturday, 4 May 2013

Resist the Annuals! (for a couple of weeks)

Fibrous Begonia
This weekend's weather forecast for Vancouver promises the beautiful sunshine we have all been waiting for throughout the first half of our cool, rainy spring.   The garden centres are packed with gorgeous reds, yellows, pinks, and blues of spring annuals.  

Yesterday I visited a garden centre to buy some Seasoil for a planter, and I could not resist wandering the aisles looking at all the bright, cheery flowers, especially festive on such a sunny day.  I started pondering what annuals would complement the new garden we installed at our parents' home, but I stopped myself.

Professional gardeners follow a rule in the Lower Mainland to not plant annuals until the Victoria Day weekend.  This date is considered the safe date after which temperatures won't suddenly dip, and the annuals will be set back.  An easy way to gage planting annuals is to wait until the municipal summer annuals are installed in parks and focal areas of municipalities.

Annuals are grown in greenhouses, protected from the elements.  If we put them out in our gardens too soon, the annuals may not die, but they may spend a lot of energy fighting to survive;  energy that they could be using to bloom had they stayed in a protected environment a little longer.

This weekend we are also expecting record breaking heat temperatures which are not predicted to last.  We do not want to scald or fry any new plantings, so try to resist buying annuals this weekend.  

If you want to be outdoors, spend the time working your composter, and separating out the usable compost.  Weed parts of the garden.  Check your plants' health and happiness.  Do a sun/shade analysis of your garden to see how the big plants have grown and affected other plants in the garden.  Basically, fosick about and get reacquainted with your garden.

Monday, 29 April 2013

What's blooming in Vancouver - April 25 pt 3

Dicentra formosa or Pacific Bleeding Heart
A couple of excellent ground covers for the deep shade garden are Dicentra formosa and Oxalis sp.  I want to emphasize that the Oxalis is good in deep shade, because I believe the lack of light may slow its progress.  There can be a danger of the Oxalis being invasive.

There are about 500 varieties of Oxalis spp, and I can't remember which one is shown in the top photo.  I can say that it grows beautifully all year round, and tumbles gracefully over the paver driveway, softening the hard edge.  In this situation, the Oxalis is growing at the feet of Rhododendrons and Oemleria.

Dicentra, or Bleeding Hearts, are such unusual flowers.  The native D. formosa has feathery leaves and smaller flowers than the classic Dicentra.  Like the Oxalis, Dicentra spreads by rhizomes.  If the soil is loose, these will spread easily.

Saturday, 27 April 2013

What's blooming now in Vancouver - April 25 pt 2

Here is one of my favourite shade plants:  Solomon's Seal or Polygonatum.  I love the delicate weep of the single stalk, covered with tiny scented white bells hanging like earrings from the stalk.  

We had a site with hundreds of Polygonatum lining the top of a steep slope.  Imagine our delight when one morning we spied a hummingbird flitting from one tantalizing white flower to the next!

Polygonatum grow in deep shade, but I like to provide staking so the single stalks do not fall over.  This photo shows my staking device forming a fence around the Solomon's Seal in the direction I know the plants will fall without staking.  If the stakes are placed early enough, the stalks of Solomon's Seal will grow over and hide the stakes.

Solomon's Seal will increase in number each year, which is terrific because it looks best in a large group.  Just make sure you have allowed enough room for a great showing.  Solomon's Seal is also easy to divide and transplant.

Plant Solomon's Seal with Hostas and Ferns, and other woodland plants.  There is also a variegated leaf variety of Solomon's Seal.