Liriope muscari has grassy foliage and spikes of blue or white flowers in the heat of late summer. It is especially accommodating as an edging or groundcover and there are some varieties with handsome variegated leaves (eg ‘Silvery Sunproof” ).
The Golden Rain tree blooms in summer making it a good choice for when the spring bloomers have ceased to be the focal points in a garden.
Whether you prefer the large hyacinths that are synonymous with the Dutch, or the smaller ones beloved by the Brits, do plant some hyacinth bulbs this fall.