Deep pink Nymphaea 'Gloriosa' water lilies at NYBG; photo by Michelle Longo
Water lilies (Nymphaea) and Lotus (Nelumbo) are jewels of the aquatic world. Symbolic in both the ancient and modern world, they are celebrated for their beauty and immortalized in art and religion. Both are pond blooming plants that emerge from rhizomes and share a rich color palette, but there are some easy ways to tell them apart:
- Water lily flowers and leaves are thick and waxy while the lotus' are thin and papery. A water lily also has a recognizable notch in each leaf.
- The water lily petal is pointed and creates a star-like bloom; the lotus petal is more rounded, sometimes ruffly.
- Lily flowers last longer, up to two weeks, then wilt and fall beneath the water; the lotus has a significant seed pod that continues to grow above the water after the inflorescence has passed.
- The lotus prefers to grow in 12 inches of water and water lilies in 2 to 5 feet.
- Some water lilies can grow as far north as zone 3 or 4; the lotus is hardy only to zone 9.
- While both attract insects, the lotus fragrance is more subtle. A water lily has a strong scent at the time of bloom that later fades.
Many of both plants are easy to grow and reward the gardener with fragrant and sumptuous blossoms from June until October.
There are two main divisions of water lilies: hardy and tropical. Hardy ones will survive our New York City winters if they are planted below the freezing line in a water feature, while tropical water lilies need to be stored over the winter or treated as annuals.
In addition to cold hardiness, tropical water lilies differ from hardy water lilies in the following ways:
- They can have larger flowers.
- Tropical water lilies have longer stalks that hold the flower higher above the surface of the water.
- They also tend to have larger lily pads.
- Tropicals come in a greater range of colors including blues and purples; hardy water lilies only come in shades of yellows, reds, whites, pinks and pastel orange.
- The tropical water lilies are more fragrant.
- They come in day-blooming varieties (diurnal) and night-blooming varieties (nocturnal); hardy water lilies are all day-blooming.
Care of Water Lilies:
Plant water lilies in plastic containers or baskets specifically designed for aquatic plants. Line baskets with burlap or landscape fabric so that the soil does not fall through the cracks. (Several sheets of newspaper can be placed on the bottom of the containers for the same purpose.) Always use topsoil that is free from herbicides and pesticides. The containers should be large enough to allow the rhizome to spread. Since rhizomes creep across the surface of the soil, a wider pot is preferred to a deep one.
Planting instructions vary for hardy water lilies and tropical ones. Tropical water lilies should be planted just like perennials. They often come as bare root plants. Place them in the center of the container and let the crown (root-stem junction) of the plant rest just above the surface of the soil. With hardy water lilies, plant the rhizome at a 45-degree angle with the growing tip positioned toward the middle of the pot, resting slightly above the soil level. Cover the soil with gravel or a thin layer of sand.
Each flower on the water lily lasts 3 to 5 days. They open during the day and close at night (unless they are nocturnal). Once the flower is finished, it will slowly sink into the water. Seed pods form and the ripe seeds fall into the soil below. Seed production uses a lot of the plant's energy. To ensure many blooms, cut the dying flowers as they sink below the surface. Follow the stem down as far as it goes and either cut it or snap it with your fingers. Clean off dead or dying leaves in the same manner.
Tropical water lilies can be stored over winter by lifting the plant from the container and storing the rhizome in a plastic bag or container full of damp sand and peat moss at 50 to 55 degrees. Remember to label your rhizomes. Alternatively, you can re-pot the water lily into a smaller container. Trim the roots and cut back the majority of the foliage. Store it in an aquarium tank making sure that the temperature doesn't get above 68-degrees; this control will ensure that the water lily is not actively growing.
Lotus will be hardy if the tuberous rhizomes do not freeze. Plant the containers so that the soil line is below the freezing mark in your pool. This can be from 6 to 18 inches deep depending on the size of your water feature. Lotuses, like water lilies, prefer six or more hours of sunlight. They die back at the end of the year. Cut them down to a few inches above the rhizome. Be patient with them in the spring as they are late to emerge. They prefer warm weather and will start to grow once the water temperature has risen above 70 degrees. The first new leaves of the lotus float on the surface of the water, while older ones are raised in the air.
Tips and Troubleshooting
- Make sure that your water lily or lotus gets enough sunlight, ideally six hours or more.
- Strike a balance between numbers of plants and surface area of the pond. Plants should cover approximately 65% of the surface area.
- Remember to fertilize your plants with tablets that you press into the surface of the soil around the plant. Do not fertilize directly into the water or you will change the pH of the water and harm both plants and fish. Fertilize plants once a month. Tropical water lilies are heavy feeders and should be fertilized generously throughout the growing season.
- Pay attention to depth when you plant your aquatic plants. Planting too high will cause hardy plants to freeze in winter; too low will prevent young plants from receiving adequate sunlight. Water lilies prefer to be planted no less than 4 and no more than 18 inches below the water's surface.
- With new plantings, initially place the pot just below the water's surface and gradually lower it as the water lily grows. Once the plant is established, the pot can remain at the desired depth.
- Remember to use good maintenance practices; clean off old, yellowing leaves and spent flowers to keep your plant healthy.
- Research the ultimate size of your plant before you buy it. A water lily with a six foot spread will not thrive in a whisky barrel or small tub. There are plenty of options available on the market in all colors and sizes.