The huge blooms of the Egyptian lotus (Nelumbo nucifera) -- up to 12 inches across in colors including pink, red, white, and yellow -- are as exotic and extravagant as Cleopatra herself. Keep in mind that this lush water plant can reach 5 to 8 feet tall and 4 to 8 feet wide, and requires plenty of space and sun. Lotuses will grow in U.S. Department of Agriculture plant hardiness zones 6 through 10 without protection, and in USDA zone 5 with protection. Start lotus tubers in late spring.
Fill a container with 4 inches of a mix that is 4 parts clay garden soil and 1 part composted manure. Choose a large, waterproof container 2 to 3 feet across and 9 inches to 1 foot deep, with no drainage holes. If you don't have clay soil, try a mix of 3 parts additive-free clay kitty litter, 1 part sand, and 1 part composted manure.
Set the lotus tuber on top of the soil at the center of the container with its growing points facing up. Place a large, flat rock over the tuber to help hold it down, but don't cover the growing points. Add 2 more inches of soil and top it with 1 inch of pea gravel, making sure the tuber's growing points protrude above the gravel. Pour water slowly into the container until the gravel is covered by 2 inches of it.
Leave the container in a warm and protected spot outside of your water garden until the temperature of the pond or bog heats to 70 degrees Fahrenheit. Lower the container into the water garden, until the lotus' growing points are covered by 2 to 6 inches of water. Use rocks, bricks, cement blocks or inverted flower pots to support the container at the right height. If you are planting more than one lotus, space them at least 3 feet apart.
Push 10 gram 10-26-10 fertilizer tablets into the soil around the edge of the container, using one tablet for each gallon of soil, once the lotus has developed six leaves. Add new tablets once a month until late summer.
Dust the lotus' leaves with diatomaceous powder if you have insect problems. Or spray them with a solution of 4 tablespoons of the powder mixed into 1 gallon of water. Do not use other insecticides, such as horticultural oils or insecticidal soaps, on your lotuses, as they can harm the plants.
Lower the lotus' container to the bottom of the deepest part of your pool or bog for the winter, if you live in USDA zone 5. Make sure the container is covered by at least 6 to 12 inches of water. In a warmer zone, you can leave it in place.
Pull the container out of the water after the first frost, if you prefer to take it indoors over the winter. Snip off any dead leaves and enclose the container and its tuber inside a large plastic bag, such as a garbage bag. Store that bag in an unheated garage, basement or greenhouse where the temperatures never dip below freezing.
Lift the lotus container out of the water or out of its plastic bag in late spring. Repot the tuber in fresh soil and a larger container, if necessary. Place it in a warm, sunny spot, and wait until the temperature in your water garden has reached the 70 F before you sink the container into it.