June is the time in the North when gardeners experience the culmination of spring's fabulous flowering show. Summer will have garden phlox (Phlox paniculata) and its other star performers, but the last month for a yard jam-packed with perennial flowers in many landscapes will be June. Take advantage with these top selections.
Sun-loving Chinese peony(Paeonia lactiflora) has a lot going for it. Everyone agrees that the fragrant, large, double flowers are lovely. A nice bonus, though, is that it is one of the longest-lived perennials. Listed for zones 2 to 9, it is also one of the hardiest perennials. Perhaps its one drawback is that it does not like to be moved; if you must transplant it, do so in fall, once it enters dormancy.
Dark Purple Allium is another favorite of ours. There are several kinds of flowering onions (Allium spp.), and they bloom at different times of the year. But there is one particular type with very dark purple flowers, Allium atropurpureum, that blooms in June.
Technically bulb plants, flowering onions nonetheless come up every year (for a number of years) like perennials. Give Allium atropurpureum full sun and grow it in zones 4 to 8.
The chief asset of flowering onions is that, since the different types bloom at various times, they are valued by those seeking continuous sequence of bloom. There is a flowering onion out there for you to plug into that empty spot in the garden whether you need it for spring, summer, or fall. A drawback against them is that they are poisonous.