Fertilizing existing iris flower beds should be done after the flowers have wilted. Cut off spent flowers so that the plants can focus their energy on the rhizomes and not on the seed pods. Planting iris bulbs is best done from late summer to early fall, usually from mid-July to mid-October, depending on your location. Those living in southern climates may delay planting until November.
Planting in spring is not recommended, but can be done in special circumstances. Spring planting can often lead to a lack of flowering for a season or two and slow establishment. It is highly recommended to fertilize iris plants during their first year, and any year after that, to increase their health and vigor. Bone meal is often applied below the mass of the iris at the time of planting (usually in late spring) because the phosphorous in bone meal is ideal for new iris rhizomes that are creating bulbs.
Unlike other types of irises that grow from rhizomes, Dutch irises grow from teardrop shaped bulbs that are planted in the fall. Fertilizing your iris plants can help extend their flowering season and get the best possible results with a hard-working iris. If you suspect the presence of an iris borer, dig up an entire group of iris bulbs, divide it with a sharp knife and examine the roots and rhizomes. Siberian irises are still one of the easiest iris plants to grow; some flowerbeds continue to bloom for decades without any division or insecticide, forming a large stripe of blue, lavender, white or one of the new multicolored colors.
If your garden is in partial shade and you're downwind from your yard, consider planting stinky lilies, which tolerate some shade, according to the Missouri Botanical Garden. BlomsBulbs sells a mix of what they call English iris bulbs (iris latifolia) that includes purple, white, blue and mottled irises. The spotted or striped leaves of an iris plant may indicate the presence of iris borers, which is more common in the eastern U. S.
UU. An advantage over bearded irises, English irises bloom later in the year and bloom in June and July. Now that you have all the information about iris nutrition, you can take the necessary steps to feed your hungry Iris plants. Every gardener knows that they can be some of the easiest perennial plants to grow and that they will delight both the gardener and guests of the house, but a simple fertilization program can make all the difference for your garden's success.