Cultivating Waterlilies ‘Less Work Than Cutting Grass’
Why not waterlilies? Are they really such an impossible idea for the garden, something only for large estates and public parks?
“There’s really nothing easier to grow,” said George Knopf, who has grown water lilies for more than 28 years in his Sylmar back yard in “pools” as small as 2 feet across, and even in containers.
“They’re less work than cutting the grass, though you do have to follow a few rules and grow kinds that do well in Southern California,” he said. “I think it’s the word pool that scares people off.”
Knopf has made a specialty of finding the varieties that thrive in our climate, varieties that bloom near the beach where there is sometimes not as much sun and heat as waterlilies like, and in the inland valleys where there is plenty of heat, but also the occasional cold of winter. Some of these varieties are his own hybrids.
He has found that most of the blue-flowered tropical lilies freeze in his San Fernando Valley back yard, or are just too difficult to grow otherwise, though he does have one that has survived for many years. This one even made it through last winter’s cold, surviving one night under an 1 1/2-inch thick sheet of ice.
For the most part, however, he grows what are called “hardy” lilies, which will not be fazed by cold and do not need as much heat as the tropicals.
The kinds he grows--about 26 varieties--begin flowering in March and keep at it until October. Anything less in the way of performance he weeded out long ago, though he continues to try the new varieties as they come along, most recently a batch out of France that were a great disappointment.
As for the pools of water required by these lilies, they can be quite small. There are miniature lilies--Knopf grows one named ‘Pygmaea Helvola,’ with tiny yellow flowers that will grow in a large container or flower pot with the drainage hole plugged up.
The flowers on this one are only about an inch across and the leaves stay in a tight circle spreading no farther than 18 inches.
Grow in Containers
Many more are small enough to grow in something the size of a half-whiskey barrel (which make excellent containers for lilies but only after some laborious work, cleaning out the charcoal and leaching out any whiskey that remains) or a very large flower pot. This is perhaps the best size for beginners, and I for one, can testify that you can grow lilies for years in these big containers with practically no effort.
The ideal pool--the next step up--for medium-sized lilies--those with the biggest and most frequent flowers--would measure about 5-by-8 feet across, and should be 20 to 24 inches deep. Should you consider making such a pool, remember that the depth is most important because water lilies need a certain amount of water above their crowns. The minimum is about 6 inches; the maximum about 14 inches.
Knopf cautions that plastic cement should be used, not Portland cement, because Portland cement is too porous and you will be forever filling the pool with water. Or use a plastic plaster to finish the inside of the pool to make it watertight.
Another alternative is a special flexible liner. Flexalon (P.O. Box 12810, San Luis Obispo, Calif., 93406) makes one of tough polyethylene resin that measures 8 feet by 12.5 feet.
How to Plant
Most of Knopf’s pools are about this size and two or three tubs of lilies grow in each. The lilies are always planted in big plastic tubs, the kind sold at hardware stores for general utility use. They measure about 18 inches across by 9 inches deep. There should be no drainage holes in the bottom.
To plant a lily, place three tablespoons of a complete granular fertilizer in the very bottom and cover with ordinary garden soil--dirt. (Use any kind, with numbers such as 10-10-10 on the label, as long as it contains no weed or insect controls.) Do not use amendments or potting soil.
Plant the lily off to one side so it has room to grow across the tub. Hardy lilies grow from horizontal tubers. Do not cover the top of the plant with soil and do not cover the soil with pebbles; it will muddy up the water at first, but settle out quickly.
When you put the tub in the pool or container, do not worry if the leaves do not reach the surface. They will elongate and be floating on the surface within 24 to 36 hours. On new plantings, do not pick off old leaves, even if unsightly, because that is where the eggs of water snails are and--in a pool--the more snails the better. Wait until the eggs hatch.
On older plants, you can control their size by simply removing leaves that spread farther than you want.
Lilies need to be repotted every two to three years and this is best done in March, but you can plant a new lily at any time of the year.
Never Clean the Pool
What about maintenance? Says Knopf: “We never clean our pools.” (The last cleaning was done right after the big Sylmar quake when two pools developed cracks.)
This is where many beginners go wrong. Do not change the water once you get the pool started. This even applies to container ponds. In my own garden, I have grown water lilies in two large concrete containers and a half-whiskey barrel for well over 10 years and have never changed the water.
Fish and plants are the secret to a clean pool. Knopf recommends what pet shops call “feeder” goldfish--the kind that cost almost nothing and are destined to be dinner for a pet reptile. (Several in my own ponds were spared this fate when my son bought too many for his snake; others were the prizes at a school carnival.)
Don’t consider koi because they eat everything in sight, even the water snails. In very shallow pools or containers, guppy-like mosquito fish will control those insects, but they do not eat algae, so are a poor second choice to common goldfish.
Use Goldfish, Water Plants
Goldfish and water plants keep pools in balance, as long as the pool is small, or deep if it is large. Large, shallow pools are algae factories. Pools may turn green at certain times of the year but this is normal and is actually appreciated by the fish. No matter what, do not change the water, just be patient and wait for things to clear.
Where do you get waterlilies? Some nurseries carry them at this time of the year, and there are several specialty nurseries in Southern California. Check the phone book.
George Knopf operates a small lily nursery behind all his ponds where he sells his favorite varieties for between $20 and $30 a pot, and these are blooming plants. Other kinds of water plants sell for about $5 a pot. Be sure to look at his own floriferous varieties, including the bright yellow ‘Chrome III’ and rainbow-colored ‘Sunset III.’
His card says “Visitors Always Welcome,” but you might call in advance. The address is 13382 Glenoaks Blvd., Sylmar. The phone is (818) 367-3175.
