Knock-Out Water Lilies

To grow knock-out, show-quality water lilies in your pond, only three cultural requirements are necessary:

  • Full Sun – This means at least seven or more hours of unobstructed sunlight per day. While some varieties will tolerate less and still bloom to a degree, full sunlight is a mandatory requirement for truly awesome plants.
  • Adequately Sized Pot or Planting Pocket – A minimum size pot or pocket for most hardy water lilies is approximately 16 inches by 7 inches. A commercial pot is readily available in this configuration. Anything smaller than this is simply inadequate for most varieties. A much larger pot will make the plant harder to manage, (lifting comes immediately to mind) but will increase the intervals between the necessary re-potting/dividing. A pot or pocket this size will accommodate most cultivars for up to three years before repotting/dividing is needed. The hardy water lily rhizome actually travels across the soil horizontally, necessitating the wide pot or pocket.
  • Fertilizer – Plants, like most living things, simply love to eat, and water lilies like to eat a lot. They are almost gluttonous in their appetites for food. They should be fertilized generously according to the fertilizer directions. Fertilizer may be in either tablet or granular form, consisting of an instant or readily available release formulation, or a time-release formula, releasing nutrients at a fairly consistent rate over a given rate of time varying from 30 to 360 days. A combination of both works the best.

Low Maintenance Beauties

Maintenance on any water lily – hardy or tropical – is minimal. If the three simple cultural rules have been followed then little else should be necessary to keep them healthy and flourishing. A couple things to keep in mind though; water lilies do not like moving water or water from a fountain or waterfall splashing on their leaves. They do not like to be harassed by chewing or sucking insects, (or trampled by a large canine) so if any sign of insect infestation is evident then try to identify the offending pest and use appropriate treatment.


Water lilies respond to conventional treatments like most any other plant, but many standard pesticides are toxic to fish, and are not labeled for aquatic use. A lot of pond owners prefer to go the safe route and use compounds that are not harmful to fish and other aquatic life.

During prolonged periods of summer rainfall, water lilies, just like terrestrial plants, can develop fungal infections that can result in leaf spotting or entire sections of leaf turning black and dissolving into mush. Don’t panic, just keep removing the affected leaves until the sun comes out and Mother Nature affects her own cure. These plants have survived for millions of years, and volumes have been written in the annals of aquatic weed control on how to kill them … a much more difficult proposition than keeping them alive and flourishing.

Water lilies are constantly producing new leaves throughout the season, and the old ones, like spent flowers, die. Removal of the spent flowers and leaves is desirable from an aesthetic and ecological perspective. It just looks nicer when yellowing leaves and decaying flowers are not present in your pond. And getting rid of any decaying plant debris is always good practice when maintaining a balanced ecosystem pond.

Article and photos submitted by Aquascape, Inc.