Hort Shorts
- To divide iris, lift entire clumps and shake off excess dirt. Cut leaves back by one-half to one-third. Using a sharp knife, cut the rhizomes (rootstock) into sections, with each new transplant including a “fan” of leaves, a few inches of firm, plump rhizome, and several roots. Discard outer sections of rhizome and any small pieces. (Be on the lookout for any holes in the rhizomes. These are signs of borer caterpillars, a common iris pest that tunnels through rhizomes. Remove caterpillars with a knife, and discard heavily infested rhizomes.) To replant irises, dig a shallow hole, mound the soil in the center and spread roots downward around it. Plant so that the top of the rhizome is visible at the soil surface.
- To divide daylilies, lift clumps with a garden fork. Shake off dirt and look for natural divisions at the base of the leaf fans. Separate these with a sharp knife or spade. Trim foliage back by about two-thirds and replant individual clumps. You may wish to trim the roots some also.
- Direct-sow seeds of quick-flowering annuals like zinnias, sunflowers and marigolds now for color until frost.
- Don’t fuss over feeding cosmos—they prefer infertile soil. Over-fertilizing produces lush foliage at the expense of blooms.
- During hot, dry weather, survey your perennial flowers to see which ones are thriving. Think about how you can fill in bare spots, where plants have succumbed, with hardier selections.