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..
Trimming of Foliage. Iris foliage can persist into winter depending on the plants' variety and the temperature. It is OK to cut back the leaves any time after they begin to yellow or become limp. Cut back the foliage of both bearded and Siberian irises to within 6 inches of the ground.