How to Plant Water Lily & Iris Bulbs for Water Gardens

Water Lilies

• 1

  Plant water lilies in spring, when temperatures warm to 60 degrees Fahrenheit. Use wide, shallow growing pans such as cat litter trays for these long tubers. Ideal measurements for trays are 12 to 18 inches wide and 6 to 10 inches deep. Don't use containers with drainage holes.

• 2

  Mix organic compost and topsoil in equal parts to give water lilies a heavy, rich and steady soil mixture. Lighter potting soils float away in the water. Fill the growing pans two-thirds full of soil mixture and moisten the soil for planting.

• 3

  Plant water lily tubers against one side of the growing pans, with the tops of the tubers angled up and toward the center of the pans. Cover the tubers with soil, but leave the tips exposed. Plant one tuber per growing pan.

• 4

  Press aquatic fertilizer pellets into the soil around the tubers according to manufacturer directions. Cover the soil with 1/2 to 1 inch of pea gravel to keep it in place.

• 5

  Place each water lily pot at a depth of 6 inches to start, in areas with full sun exposure. Move the pots gradually deeper to a maximum depth of 12 to 18 inches as the stems grow. The foliage should always sit at the surface.

Water Iris

• 6

  Plant water iris rhizomes in fall to give them winter rooting periods. Use deep, wide pots at least 8 inches deep and 16 inches wide to give the plants room to grow.

• 7

  Fill the pots three-quarters full of the compost and topsoil mixture. Plant iris rhizomes 4 to 6 inches deep, with the growing node facing up, and press soil firmly over them.

• 8

  Push aquatic fertilizer pellets into the soil per manufacturer directions. Cover the soil with 1/2 to 1 inch of gravel to keep it secure in the water.

• 9

  Put water iris pots in areas with full sun, at a maximum of 4 inches deep. If you plan to keep the water iris pots out of the water, keep the soil consistently wet with daily waterings.