Both water lilies (Nymphaeaceae spp.) and irises (Iris spp.) add color to a water garden for families to enjoy. These aquatic plants thrive on the water's edge where they sink their roots into the pond's mucky bottom while keeping their heads above the water. Tropical lily varieties can overwinter only in United States Department of Agriculture plant hardiness zone 10, though hardy species can grow in USDA zones 3 through 9. Irises grow in USDA zones 3 through 8. With their strap-like foliage and tongue-like flowers, irises stand tall in the water while water lilies' heart-shaped leaves float on the water's surface waiting for a passing frog.
Fill a 1-gallon black pot to within 1 inch of the rim with clay soil. Press the clay down lightly. While you can use other colors of pot, black plastic pots will be almost invisible to the casual viewer.
Create a hole where you want to put the iris or water lily bulbs. The hole should be about the size of the bulbs themselves and slightly deeper. Each pot can only hold one water lily bulb, but you can plant several iris bulbs in the same pot by leaving a 1/2-inch space between each bulb.
Place a bulb in each hole, root side down. Usually the bulbs will have small string-like roots visible, but some bulbs only have a puckered scar on the bottom and a pointed top. A few lilies will have the point at the bottom. If in doubt about which is the top and which is the bottom of your bulb, plant the bulb sideways and let the plant figure it out.
Firm the clay soil around each bulb. Be careful not to break off any emerging stems.
Add 1/2 inch of gravel to the top of the pot to keep the soil in place.
Place the pot in the water so that the lip is at least 1 inch below the water line for iris and up to a foot deep for water lilies.