Fertilization and Maintenance

1. • Aquatic fertilizers specify 1 tablet per 1 gallon (3.8 L) of soil, while other products recommend 2 to 4 tablets for the same amount of soil.
2. 
   
   
   Bring tropical lilies inside when the water temperature dips below 65 °F (18 °C). If your pond freezes solid, you’ll need to winterize hardy lilies inside, too. Store the pot in a large aquarium filled with water.

   • If you can't store the entire pot, trim the leaves and remove the rhizome, then apply a dusting of fungicide. Store the rhizome in a plastic bag filled with peat moss, and keep the bag in a cool, moist place, such as a basement.
   • If your pond is at least 18 inches (46 cm) deep and doesn’t completely freeze, you can winterize your hardy lilies outside. Place the pot in the deepest part of the pond, where it'll be protected from cold air.
3. 
   
   
   Divide an overgrown lily every 2 to 3 years.Eventually, the rhizome will start to crowd the pot, and you’ll need to divide it. In the spring, remove the rhizome, or root ball, from the pot and rinse away excess soil from the roots. Look for tuber-like shoots with distinct growing tips or emerging stems. Using a knife or pruning shears, cut the shoots and surrounding roots in lengths of at least 3 inches (7.6 cm) from the rest of the root ball.You’ll likely be able to divide the root ball into several shoots. Plant each shoot in a separate container, then place them in your pond or give them to a friend.