Water lilies are one of the most popular pond aquatics because they are colorful, easy to care for, and highly fragrant. Tropical water lilies come in day-blooming and night-blooming varieties. They have larger, more-fragrant blossoms than hardy lilies, come in more colors, and bloom more often — usually every day for the entire blooming season. In northern areas, they bloom later in the season. They can be placed in the water garden when the temperature reaches 65F at night and 75F during the day and grow best in 10 to 12 inches of water. Unless stored, they die when frost occurs. Most gardeners store them in a greenhouse pond over winter or treat them as annuals and replace them every year.
There are a great many types of water lily, from the huge, spectacular, Amazonian ones several feet across, to the more humble White water lily (Nymphaea alba) which is native to Britain They prefer perfectly still water, so vigorous fountains, waterfalls and streams are out. The main reason they prefer this is that rapid currents keep water temperatures too low.
To grow at their best, water lilies prefer to be in some kind or container, or basket, and grow in nice rich soil containing lots of organic matter. When you purchase your water lilies from the nursery, they should come complete with the necessary plastic slitted growing basket. If not, these are readily available from most garden centers, or water garden specialists. These containers are especially useful as they will float and still contain the necessary rich compost.
However the most glorious water lilies are the tropical and hardy varieties. One plant will multiply to blanket an area of four to six feet. They are exceptional because they bloom both day and night.
Lilies should be planted in pots at least 10″ in diameter. Follow this advice because the smaller your container, the smaller your blossoms will be.
Before submersing the tuber in the pond, fill a play or plastic pot half full of loam garden soil (if it is not already sold to you in a pot) and two to four fertilizer tablets (also usually sold with the plant.) Top off the pot with the rest of the soil. Set the tuber upright, with the tip exposed. It is the roots that need to be buried in the soil.
Once you have set the tuber correctly, sprinkle an inch or two of pea gravel or sand on top to prevent soil from escaping when the pot is submerged. Be careful not cover the top of the tuber with this gravel or sand or it won’t grow.
The plant can now be lowered into the water to a depth of approximately 6 inches over the crown of the water lily. As the plant grows, it can be lowered to a depth of 12 inches.