Dahlias are incredibly easy to grow and provide some of the biggest and most spectacular blooms in the garden.   In just a single season, Dahlia plants grow into a full and lush bush, opening their brilliant, abundant blooms non-stop from midsummer through the fall.  With thousands of dahlia varieties to choose from, you can find them in a rainbow of unique colours, different styles and unexpected flower shapes. Dahlias range from the miniatures, just a few inches tall with the 2-inch lollipop-style pompons to the huge-flowered "Dinner plates" with their wonderful big glossy-leaved plants that grow up to five feet and bloom with flowers 10 to 12 inches across.