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..
Irises may not bloom for several reasons. * Too much nitrogen-cut down on the nitrogen element in any fertilizer that you might be using. * not enough nutrients or water (but be sure not to overwater, though, which can encourage rot). * not enough sun-they should get at least 6 to 8 hours of full sun each day.lso, iris stop blooming when they are crowded and need to be divided every 3 to 5 years. Divide and replant in July, August or September when they are sleepy due to the heat. When you replant, ensure that the iris plants have good drainage. Water can not stand in the beds.