Here are averages that might help you know how often you should change the air filter at home: Vacation home or single occupant and no pets or allergies: every 6-12 months Average suburban home without pets: every 90 days
Rating Newest Oldest. Best Answer: Cut off dead blossoms and dead bloom stalks when the iris has stopped blossoming, but don't cut back the leaves until they begin to turn brown in the fall. The leaves are needed to produce next year's blooms. When you do cut, leave a fan shape about six inches long. Feed your irises a teaspoon of bone meal every fall and when you replant. You can feed again a month before they usually bloom if you like, but they are quite tolerant of just one feeding..
As the leaves slowly die back and turn yellow, they return nutrients to the rhizome. Cutting back iris leaves before they turn yellow deprives the rhizome of important nutrients, which means the iris will not grow as well come the spring. Nutrient-rich rhizomes, on the other hand, will not only produce large, beautiful blooms, but will also spread quickly to form large clumps of showy irises.