Delphinium Seeds - Pacific Giant Series2nd Year Maturity. Growing Pacific Giant Series delphinium seeds this season is a classic and vibrant way to invigorate any stale flowerbed, walkway, or patio. Pacific Giant Series seeds mature into dazzling 48 60 tall delphiniums bursting with hardy blooming stalks perfect as a fresh cut substitution to more traditional larkspur or snapdragon. Pacific Giant Series delphiniums boast nearly 100% fully double blooms and are cultivated for their dense