Have you ever wanted to grow a water lily or two in your garden but weren’t quite committed enough to start digging a hole in your backyard for a pond? Well, don’t despair, there is another way to enjoy these beauties, even if you live in a condo or apartment with a small patio or balcony.
Large water-tight pots and tubs make excellent “mini ponds” for small-statured aquatic plants. We experimented with a couple of simple combinations at Olbrich Gardens last year with great success. One container was planted with hot colored (yellow, orange, red) flowering plants and the other with cool (white, blue, purple) [see sidebar]. You may want to start out with similar plantings and build upon them as you gain more experience. Don’t be discouraged if you can’t find the exact plants since there are many excellent substitutes which will work equally well.
We grew our plants in large terra-cotta colored plastic containers that measured 30” across at the top, 18” at the base and 28” deep. Any container with similar dimensions will work as long as it is water-tight and free of chemicals (e.g.. creosote-treated wood) that could leach from the container and be toxic to the plants. The plastic pots we purchased were hole-less, but if you can only find them with holes it isn’t too difficult to seal them up with some silicone caulk or similar compound.
The container was filled with tap water and left to sit for several days so that the chlorine and fluoride had time to dissipate and the water time to warm-up a bit.
Water lilies were potted into 2 gallon pots and the others in quart or 1/2 gallon containers. All the plants were potted into a heavy clay garden soil and topped off with an inch of pea gravel before slowly submersing them into the one large container. The individual pots were placed on stacked bricks to raise them closer to the surface -- how close varies with each plant species (see sidebar).
After planting, a touch of dye (available from most aquatic suppliers) was added to the water to block out sunlight and discourage algae growth. Plants were slow to “get going” initially but once the temperatures warmed up, they grew by leaps and bounds. Maintaining the plants was less work than we anticipated and was actually quite enjoyable. Besides the obvious topping-off the container with water as it evaporated, we also had to regularly fertilize and groom the plants. We never aerated or changed the water during the season and didn’t add any fish or other critters to the pots -- but it is an option for added interest.
We fertilized individual pots about every 2 weeks with aquatic fertilizer tablets (check the package for rates since it may vary by manufacturer) by pushing them 2-3” into the soil. Plant grooming was limited to removing spent flowers and yellowing leaves and occasionally skimming off any algae that began to grow.
At the end of the season the individual pots were taken out of the water and placed into a root cellar for the winter at a temperature of about 35-40¼F. The pots were out of standing water, but watered several times during the winter to keep them from drying out. A cool basement or slightly heated porch or garage would work equally well as long as it was cool but not freezing. In spring, the plants were divided and re-potted to grow again for another season.
There are a number of mail-order nurseries that specialize in aquatic plants, but I suggest shopping locally if possible. Not only is it a great idea to support local businesses, but the plants are often potted rather than bare-root and in much better condition. Due to specialized production techniques aquatic plants tend to cost a bit more than “normal” perennials, but they’re worth it. In the Madison area The Bruce Company, The Flower Factory, Johannsen’s Greenhouses and Jung Garden Centers all sell aquatic plants and the necessary paraphernalia needed to get you started.
Venture into the world of these exotic beauties and experiment with them as you gain experience-- they’re sure to give you many seasons of gardening pleasure.
Note:
The Hot-Colored Container consisted of a number of low growing plants
(scientific names and the approximate depth that the top of the pot should be placed below
the surface of the water is indicated in parentheses): a yellow-flowered hardy water lily
(Nymphaea pygmaea ‘Helvola’ - 10”) , parrot’s feather (Myrriophyllum
aquaticum - 6”), and water hyacinth (Eichhornia crassipes - floating).
Medium growers included: miniature red lotus (Nelumbo ‘Red Bowl’ -
6”), chameleon Korean houttuynia (Houttuynia cordata ‘Chameleon’ -
2”) and yellow variegated Japanese sweet flag (Acorus gramineus
‘Ogon’ - 2”). The tallest plants were: miniature cattail (Typha minima
- 3”), and zebra bulrush (Scirpus lacustris tabernaemontani
‘Zebrinus’ - 10”).
The Cool-Colored Container was planted with low growers such as: a yellow changing to pink-flowered hardy water lily cultivar (Nymphaea x ‘Aurora’ - 10” deep from the surface of the water to the top of the container) and pink bowl lotus (Nelumbo ‘Pink Bowl’ - 6”) Three medium growing plants included: double white-flowered Korean houttynia (Houttuynia cordata ‘Plena’ - 2”), corkscrew rush (Juncus effusus ‘Spiralis’ - 4”), white variegated Japanese sweet flag (Acorus gramineus ‘Argenteostriatus’ - 2”) and pickerel weed (Pontederia cordata - 4”). The only tall grower was variegated great bulrush (Scirpus lacustris ‘