The care information provided in this section represents the kind of practical advice is available for all the plants in this web site if you subscribe to the monthly customized newsletter Yardener’s Advisor.
Lilies-of-the-valley grows best in moist soil. They prefer at least an inch of water a week from rain or from a watering system, especially in hot weather. When rainfall is scarce, check soil moisture in the root zone to see if supplemental watering is necessary. These plants don't need much water while they're flowering, but regular moisture later encourages rooting and helps the rhizomes store up nutrients for next season. For information on products see the file on Choosing Watering Equipment
While lilies-of-the-valley do not require extra feeding if the soil is reasonably rich, they do benefit from an annual late fall feeding. Sprinkle a handful or so of fertilizer over each 4 square feet of lily-of-the-valley bed for the rain to soak in. For more information see the file for Fertilizer Products
One way to acquire more lily-of-the-valley plants and keep existing beds from becoming overcrowded is to dig up clumps and thin them. Smaller flowers and weaker plants signal that it is time to do this. Divide them in the spring. Dig up a clump with a spade, garden fork, or trowel and gently separate the plants making sure you have at least one pip with some roots and a lateral bud, from which new growth will emerge. Replant some in the original site with more space between them, and use the extras elsewhere on the property. Seeds that drop from lily-of-the-valley plants will often produce more plants in the bed.