Bulb gardens include spring bulbs as well as summer bulbs. Some tuberous-rooted and rhizomatous plants such as begonia and iris are also considered summer bulbs. In order to thrive, bulbs must be watered correctly. They are prone to rotting if there is too much water or to dying if there is not enough. Most bulbs are perennials, so maintaining the proper soil moisture year around is necessary for them to remain healthy for many seasons.
Plant bulbs to the proper depth. Plant true bulbs and corms, such as daffodils or crocus, to a depth three times their width. Plant tuberous-rooted plants and rhizomes so that the top of the root is just visible at the soil's surface.
Water thoroughly at the time of planting to ensure that the soil is evenly moist to an 8-10 inch depth. Providing approximately 2 inches of water at planting is sufficient.
Water as needed to maintain soil that is moist but not soggy while the plant is actively growing. Spring bulbs require little additional water as they grow during the cool period of the year when the ground is still damp from winter. Water summer bulbs during extended dry periods.
Apply a 2-inch layer of bark mulch around each of the plants but not directly on top of the crown. This preserves soil moisture between watering or rainfall.
Remove the bark mulch in the fall. Replace with a 4-inch layer of straw mulch over the bed to preserve soil moisture and to prevent frost heave of the soil during winter.