Dutch iris bulbs are typically planted in full sun and are often used as cut flowers. Dutch irises bloom in late spring to mid summer and are available in many varieties. The bulbs are considered hardy and need little care to survive, even during the winter. However, there are several things you can do to help care for your Dutch iris bulbs so they bloom and thrive.
Water your Dutch iris bulbs right after planting (generally in the fall). Then only water them during the growing season during long dry spells. If you notice that puddles remain five hours after a hard rain, consider transplanting the bulbs or amending the soil with some compost. A lingering puddle indicates that the soil is not draining well, and root rot and disease can occur over time.
Allow the foliage to die away before pruning it back. This allows the leaves to soak in as much sunlight as possible, thus the process of photosynthesis will make lots of sugar (plant food). The food is stored in the bulb for next year's growth.
Add extra mulch for the winter. Mulch dissipates over time and you need to add more on occasion. Winter is the perfect time to do this to add a layer of insulation that will help keep the bulbs nice and cozy underground until the next year.
Divide Dutch iris bulbs every three or four years in the fall, especially if you notice the blooms are not as large or as many as previous years. To divide Dutch iris bulbs, simply dig them up, divide them with your hands and replant them in a new location, 4 inches deep and 3 inches apart from one another.
Store unplanted iris bulbs in a paper bag, mesh bag or open box. Add a few handfuls of moist peat moss so they don't dry up. Place them in a cool (50 to 60 degrees Farenheit), dry and dark location (e.g. garage, crawl space, attic) until you are ready to plant them, generally in the fall or in early spring. Check on the bulbs every few weeks to moisten the peat moss again, if necessary. Discard any rotting bulbs.