If your garden has a moist area that also gets full sun and you want beautiful three foot-tall, six- to eight-inch flat flowers that bloom in late July, here is a delight you can add to your garden: Japanese water (or Ensata) iris.
Japanese irises require ample moisture, especially up to bloom time. They will do very well beside a stream or a pond, but in cold climates they may suffocate or rot under ice in the winter. Or just give them extra water in your regular garden.
Soil Requirements: Japanese irises prefer a heavy, rich soil with ample organic matter, especially composted manure or peat. If the soil is clay, the addition of the organic matter will help loosen it. The soil pH should be acidic, ideally between 5.0 and 6.5. There is evidence that Japanese irises will tolerate a wider pH range, but growth and bloom will not be as strong.
Planting: Plant strong divisions of two to three fans. The roots should not be allowed to dry out during transplanting. Soaking the rhizomes and roots in water overnight before transplanting is beneficial. The rhizome should be planted two to three inches deep, depending on the heft of the soil.
If planted in a depression of three to four inches, the depression will help to catch and hold more moisture. Since new roots form above the old roots, planting in a depression will permit the gradual filling-in of more soil and compost and help to maintain the plants vigor for a longer period of time. After planting, keep the soil moist until the plant is established. The equivalent of one inch of rain per week will keep them doing well in most soils. Do not fertilize until established after a growing season.
Time of Planting: Japanese irises can be planted almost any time from spring until fall, but spring is best because it gives the plants sufficient time to establish new roots for good bloom the next season.
Mulching: After planting, a heavy mulch of two inches is beneficial to help conserve moisture or prevent heaving over the winter.
Fertilizing: Japanese irises are heavy feeders. A liberal application of a balanced fertilizer, such as 12-12-12 in spring and just before blooming is beneficial. Weak plants showing light green foliage will be invigorated with a bi-weekly foliar and drench application of a water soluble acid fertilizer. If you want to give them optimal conditions, alternate every two weeks with Miracle Gro and extra water. Best place to buy is www.ensata.com, although Merrifields carries some varieties. These lovelies are welcome additions to the late summer garden.
Nancy Burns, owner of Garden Ideas, is a Certified Master Gardener; Horticulture Information Director of District IINational Capital Area Garden Clubs; Belle Haven Garden Club President; and Secretary, National Capital Orchid Society. Contact [email protected] or 703-329-1899.