Northern & Central Midwest
Pinch some later blooming perennials to make them stocky and full. Perennials that benefit are asters, phlox, bee balm, 'Autumn Joy' sedum, yarrow, Russian sage, balloon flower, false dragonhead (Physostegia), goldenrod, Joe-pye weed and culver's root. Pinch them back by about one half at the beginning of June.
Watch for Pine Sawfly
Watch for pine sawfly larva feeding on the old needles of mugo, Austrian and Scots pine. These gray-brown larvae stand up in alarm when the branch is shaken. Hand-pick them and drop into a bucket of soapy water. They are not true caterpillars so cannot be controlled with the microbial insecticide Bt.
Plant for Hummingbirds
Lure hummingbirds to your garden. Plant red and orange flowers with a tubular or downward shape. Some examples include bee balm, cardinal flower, trumpet creeper, cypress vine and salvia. If you use feeders, be sure to change the nectar every three to five days to prevent bacterial growth.
Prune Spring Blooming Shrubs
Spring flowering shrubs should be finished blooming, so now is the time to prune them to encourage more blossoms next year. Waiting until later in summer will prune off flower buds for next year. Prune by heading back stems or by removing up to one-third of the largest stems at ground level.
Plant cucumbers if you haven't already done so. Plan on planting vining cukes now and then plant bush cucumbers later in June. This will assure you of having a crop in case cucumber beetles bring bacterial wilt to your vines. By the time the vines succumb, the bush cukes will be up and growing and beetle populations will wane.