Tuesday, June 20, 2017

Building a Container Water Garden

One of the challenges to creating a pollinator friendly garden is to include a water source.  We have a few static birdbaths, but ours are out of the way and often ignored.  To prevent mosquito breeding in these still ponds we throw in a 'mosquito dunk' which kill their larvae.  Having visited a few gardens with elaborate water gardens I was inspired to bring those home, in a scaled down version.

The finished product 2 days after completion.
What I have assembled is a container water garden that sits on our deck in easy view of the front door.  While I really wanted to include a lotus, they require a lot more space (min. 6 sq.ft.) to do well.  Instead I found a miniature water lily with 3" leaves that are in good scale with my container.  For a vertical element I chose squarestem spikerush, a native species that grows to 2' tall.  Anything taller would be out of scale.

Let me run you through the features of this container garden and the steps to build it.  The tub itself is a plastic planter bought from Costco for under $20.  The top is 2' in diameter and it holds about 20 gal. of water.  The depth is 15-18" which allow for the lily to be about a foot under water.  The bluestone rocks are partly for decoration but some are porous enough to be a butterfly watering station.  The rocks are stacked to create a small waterfall, powered by a small fountain pump.  For this sized tub, 20 ghp is sufficient. Since waterlilies do not like moving water the waterfall is directed to the side and into the rushes to slow the flow to a ripple.  The reason for the waterfall is to add a sound element to the garden and to create enough flow to keep mosquitoes from breeding in the otherwise still water.

The steps for constructing this garden are pretty easy.  Here the parts I used are shown.  They include the container, this one is plastic but a galvanized metal tub would work as well. There are also a small submersible pump, a timer, and about 3' of flexible hose to route water for the waterfall.  The concrete blocks create a flat base for the plant pots and the decorative stones.  Since I wanted a waterfall, at least one of these stones is concave to channel the water.

The 'hardware' for the water garden.

Next there are the plants.  We are fortunate to live not too far from Lilypons Water Gardens in Adamstown, MD.  They have been in business for a 100 years supplying water garden plants, fish and supplies.  There I was able to get some advice and select plants appropriate to my needs.  Since my container only has about 3 sq. ft. of surface I needed to look at smaller sized plants.  I selected the 'Helvola' hardy waterlily, with its smaller leaves and flowers it would not look at all crowed in my small container.

Here I measured the length of the stems so that
 I could place the pot at the proper depth in the container.
Turned out the setting directly on the bottom
 was the perfect spot.

Here's the square-stemmed spikerush.  The stems have a
flat membrane at each corner that catches the light.

Here I used the concrete blocks to elevate
 the spikerush so that it would not be too deep.

After placing the plants I added a couple of more concrete blocks to create a base for the decorative rocks and waterfall.  I put the pump behind the rocks to hide the cord and minimize turbulence.  The pump hose was was positioned on top of the waterfall rock and additional stones were used to press the hose in place.

Now with everything in place I filled the tub with water until the leaves of the waterlily were floating loosely on the surface.  The water was hazy for a couple of hours, but by the next day it was clear as seen above.  

Most water lilies like full sun, some like 'Helvola' tolerate part sun.  In its present location this container gets about 4 hours of direct sunlight.  Since the flowers open in response to sun (and close up in the evening) a sunnier site will keep the flowers open longer.