Early summer, now that is, is one of the most colorful times at a Nursery (or Garden Center). The annuals have all been potted up from Market Packs or 4" pots to 5" pots or larger. Plants that had been struggling in a few cubic inches of soil are now happily growing roots into a quart or more of soil; the happy roots are reflected in happy tops with an abundance of blooms. Cannas are blooming, and Lotus and flowering tropical patio plants. This picture is part of the Annual Area at Behnke's Nurseries in Beltsville. I worked at this Nursery (they do grow many of their own plants son its more than a Garden Center) for a long time and my wife worked there longer.
It isn't just the annuals and tropicals that look good now. Hundreds of flowering hydrangeas under a lath roof are pretty impressive. Crape Myrtles have begun to flower and there are blocks of hundreds of large flowering shrubs and smallish trees in colors from white through pinks, reds, and purples with a few corals thrown in for good measure. Crape Myrtles have been extensively selected and hybridized and there are varieties that vary from low groundcovers to 40' multi-stemmed small trees. And of course the Buddleias that we ought not grow are all flowering, luring butterflies in for the praying mantids to harvest.
Most Garden Centers carry plants in much greater quantities as they come into their peak season and most grasses are at their best from summer to fall. Daylilies are peaking now so there are many cultivars flowering and available this month. I bought a nice Hydrangea yesterday and a variegated Salvia greggii. There are plants out there for the obsessed. I mean the interested.