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.

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

Polygonatum

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.

Brunnera: another great shade plant

Brunnera macrophylla flowers tucked in amongst the dafs

Brunnera is another terrific shade plant.  The first sign of Brunnera macrophylla in the spring is the Forget-Me-Not like blue flowers rising from the earth.  If the Brunnera is planted with bulbs, like the photo to the left, the delicate blue flowers provide a lovely contrast to large Daffodil heads.

Brunnera macrophylla 'Jack Frost'

Once the flowers have emerged, heart shaped leaves develop and grow.  The more recent varieties of Brunnera have interesting variegation in the leaves, from lightly variegated, to the entire leaf being white or silver.  I prefer the contrast of green veins, so I stick with B.c. 'Jack   Frost.'

Brunnera can tolerate full shade and part shade, but don't let them dry out.  Their leaves will be margined with brown, which does not complement the silver.

mycorrhizae fungi

 mycorrhizae fungi inoculant results

Whenever we install a new garden, we use mycorrhizae fungi inoculant on the plants' roots.  When I research the use of this inoculant on plants, I read many mixed reviews.  So I decided to test the product for myself.

I don't have a lab.  I don't have all kinds of electrical monitoring devices--I simply grew seeds in a growing medium with and without mycorrhizae inoculant.  All the seeds came from the same package and were planted in the same growing medium.  Half of the growing mediums had Myke mycorrhizae fungal inoculant added.

The photo to the right shows two basil seedlings:  the one on the left was grown without mycorrhizae inoculant, the one on the right grown with mycorrhizae inoculant.  They were both grown for the same number of days.

The plant on the right did much better than the plant grown without the fungal inoculant.  This was true with every seedling we tested.

The key to a healthy plant is healthy roots.  The more root mass a plant has, the more food and nutrients the plant can ingest.

Mycorrhizal fungi is a natural fungi growing in all our soils.  Plants could not exist without it.

In Canada, I believe the only maker of mycorrhizae fungal inoculant is Alberta's Myke.  Gardening centres usually carry small containers of the product branded for specific purposes.  We buy large bags of all purpose Myke from landscapers' stores.  You can contact Myke (www.usemykepro.com) for a local suppliers.

Prune roses when Forsythia are blooming

Forsythia in bloom now

The rule of green thumbs is to prune your roses when the Forsythia are in bloom.  This climate specific advice is much more useful than stating a particular week or month to prune or plant something.  We need to look for signals in our own gardens for when to care for our plants.

Throughout Metro Vancouver we have many climate variances.  For instance, one of our garden sites is at the top of Mountain Hwy in North Vancouver.  This garden is usually a full month behind our Vancouver gardens in spring.

Even within Vancouver there are many different climates.  Oceans moderate temperatures.  Both of us Cultivated Gardeners live by the ocean.  Sometimes we set off for an autumn garden clean in Kerrisdale or South Cambie, only to discover those gardens are covered in a new snowfall;  yet where we live, there wasn't even frost.

Leaving the leaves in spring

Every autumn, we cover the garden beds with leaves to protect the soil.  Keeping the leaves on site has many advantages.  

1.  Plants take up nutrients, and when the plants die back for the year, if left on site, the nutrients will go back into the soil.

2.  The average rainfall in Vancouver between October 1st and April 30th is 1150 mm or 3.75 feet for the seven months.  The average raindrop hits the ground at 24 kph or 15 mph.  This amount of water hitting the soil creates a tremendous amount of compaction.  An inch of mulch on top of the soil absorbs the impact of this much water on the soil.

3.  If the soil is protected from rain, and does not get compacted, all the useful little critters and microbes stay alive to do their good work for another season.

Often, we are asked when we will be removing the leaves in the spring.  The answer is usually, we won't remove the leaves.  An ecologically designed garden has many tiers of plants covering the soil.  In the spring, as the deciduous plants rise from the soil, they cover the decomposing leaves.  By summer, the leaves have decomposed back into the soil to provide nutrients for the earth again.

The only time we remove leaves is if they are so filled with tannins (i.e. oak, beech), that they will blow all over before they ever decompose.  These leaves go into the compost where their decomposition is accelerated.  These leaves can stay at the back of beds behind or beneath plants, but we do remove them from front entrance or feature beds.

Whenever we can, the autumn leaves get mowed up before being applied to garden beds.  Mowing the leaves speeds up decomposition, and makes the leaves small enough to provide a mulch and allows moisture to penetrate to the soil.

Be careful when using horse manure in the garden

Recently I attended an informative day of talks, hosted by Bartlett Trees.  One of the speakers discussed the issue of using horse manure in gardens.  He had noticed a lot of plant death and decay at one of his sites, and discovered the gardeners had been composting horse manure from the barns, and adding this compost to the gardens.  The horses being raised were very rare breeds, and injected with a lot of antibiotics.  Antibiotics kill off bacteria, an essential component in healthy gardens.

Because horse manure seems a natural product, many gardeners assume it is organic.  What they do not realize is how many chemicals are injected into the average horse.    

In an organic food course, the instructor recommended going to horse stable neighbourhoods to scoop horse manure off the street for food beds.  When I questioned the chemical possibilities in horse manure, another student googled my query and announced his findings:  horses are only injected with antibiotics once a year, in the spring.  The conclusion was, as long as we avoided getting horse manure within a few weeks of this injection period, the horse manure was organic.

At the time I took this course, I also worked on a horse farm.  I noticed that all of the horse manure was loaded into a truck and driven off the property.  I discussed horse manure chemical components with the owners of the horse farm.  They did not want the horse manure in their gardens because their thoroughbred horses could be injected with antibiotics as often as every six weeks.

These are two examples relating specifically to thoroughbred horses.  I do not know if regular horses receive the same kind of chemical care.  My point is, do not assume horse manure is organic.  Get horse manure from a reliable source.  Ask the horses' owners, if you can, what goes into the horses, because that is what will come out of the horses.

Vancouver rain and soil pH

Vancouver's soil is naturally acidic because of the amount of rain that falls.  

Rain is made of water, which is made of two hydrogen atoms and one oxygen atom (H2O).  When the rain falls to earth, it breaks apart into H+ and HO-.  Now the soil has more free H atoms which makes it more acidic.  

The "H" is pH is for hydrogen.  The "p" has a variety of possible explanations, including power or potential.  

The more free H+ atoms in the soil, the lower the number due to a negative logarithmic equation.  

This part can be confusing, but remember rain = more H+ in soil = high acidity = low pH.

Phosphorous and Hypoxic Zones

This photograph shows the border of a hypoxic zone, or dead zone, in the Gulf of Mexico.  Hypoxic zones are areas of the ocean where all ocean life has been killed off by excess phosphorous and nitrogen.  The excess P and N in the ocean comes from fertilizer run off.

When people use fertilizer that is not absorbed by plants, the excess runs off into our water table and creeks, streams, rivers, etc.  All of these eventually run into our oceans.  If the water running into the oceans has excess nutrients, this creates an algae bloom.  The algae bloom interrupts the normal balance of the ocean by creating an opaque cover over parts of the ocean.

When the algae uses up the nutrients in the water, the algae dies and falls to the ocean floor.  The excess algae decay process uses any oxygen left in that area of the ocean, leaving none for the other life in the ocean.  In turn, this creates a dead portion of the ocean, or a Hypoxic Zone.

Chaefer Beetles in Vancouver

Once again, crows and raccoons are dining on delicious Chaefer Beetle larvae.  These larvae are living under lawns.  The crows and raccoons dig up lawns to get to the larvae.

Why are some lawns affected and not others?  The lawn has to be easy to dig.  Crows only use their beaks, and raccoons their paws.   I have dug up lawns with deep roots, and the Chaefer Beetle larvae are under the roots, but they are safe from crows and raccoons.

Lawns that are easy to dig have shallow roots.  A lawn should not have shallow roots.  A lawn gets shallow roots from being cut too short, and not getting watered effectively.  Generally, the roots of a lawn are as long as the blades of grass.  So if the lawn is only 1" high, chances are, the roots are only 1" deep.

If a lawn is watered at short intervals, the water cannot penetrate very deeply into the soil.  If the water is not penetrating into the soil, the grass roots come to the surface looking for moisture, and again, this leads to shallow roots.

You have probably heard this before:  raise the mower blade so the lawnmower is cutting the lawn at least 2" high.  When the grass is growing quickly in the spring, 2" is a good height.  As the grass growing slows down when the weather gets hotter, lawns can be 2.5-3.0" high.

Time to Design

For anyone thinking this is the year to give the garden an overhaul:  now is the time to begin.  

Good garden design begins with a thorough analysis of the garden.  This includes soil analyses, sun/shade audits, privacy/screening issues, wind and microclimate analyses. The designer should also take inventory of the existing garden for healthy plants to retain.

The owner of the garden needs to be collecting ideas for her/his new garden. You can look around your neighbourhood for plants, arbours, fences, and other attractive features that might complement the architecture of your residence.  Alternately, gather some beautiful garden picture books and spend some quiet time reading and dreaming.

Think about how you would like to use your garden:  entertaining, playing, reading, maybe gardening.  How many people will gather in your garden?  How much time do you spend in your garden?  How much time do you want to spend in your garden?

And, of course, the owner of the garden needs to consider a budget for renovations.  A good  designer can create a design to be installed at once, or over a few seasons.  The important part is to have a cohesive design to follow.

Naturally, this is what we do at The Cultivated Gardeners, so feel free to contact us info@thecultivatedgardeners.com.

Spring Lawn Maintenance

If it is March, it must be time to start top dressing lawns with Transform's Lawn Conditioner.  We use this instead of aerating, liming and fertilizing lawns with chemical fertilizers.  

Aerating may be productive in dry climates, but aerating in Vancouver during the spring does not make any sense.  Powered aerators are large, extremely heavy pieces of equipment.  The aerating tines are attached to a great big roller.  A weight is placed in the roller to ensure the roller is forced down, embedding the tines deeply into a lawn.  As the roller rolls, the tines roll over the lawn.  

This system works perfectly on nice, dry lawns.  As the tines are rolled out of the lawn, the small cylindrical plugs of turf fall out of the tines, leaving the tines empty for the next go round.  Great idea!

However, there are no nice, dry lawns in Vancouver in the spring.  On average, Vancouver receives 75 cm, or 2.5 feet, of rain from November to February.  

When someone rolls an aerator over a lawn in March in Vancouver, after the first rotation, the tines are filled with muddy turf.  Filled tines mean that all subsequent rotations of the roller are simply pushing the turf aside to make a dent.  Few plugs fall out of the tines, so the lawn is not being aerated, but compacted.  With all the water already in the soil from 75 cm of rain falling, the last thing a lawn needs is more compaction.

What Transform's Lawn Conditioner does is give life to the soil in which the lawn is planted.  The Lawn Conditioner is filled with healthy microbes and nutrients.  Add this as a top dressing to a lawn, and the soil comes alive.  When soil is alive, it attracts the under the earth life, like worms, that in turn aerate the soil.

If you still feel the need to aerate in Vancouver, do it in September when the ground is dry.  Add some compost as a top dressing, and your lawn will be set for the winter.

We buy our Transform Products (http://www.transformcompost.com) through Greenway at Marine Way and Greenall in Burnaby (sales@greenwaylandscape.ca).