- Name: Scarlet Double Hollyhock - Scientific Name: Alcea Rosea - Color: Scarlet (Double Blooms) - Plant Seeds: Outdoors After Frost / Indoors Weeks Before Last Frost - Bloom Time: Summer - Fall - Hardiness Zone: 4 - 9 - Plant Height: 60 - 84" - Plant Spacing: 24" - Light Requirements: Sun - Part Shade - Soil & Water Preferences: Average - Dry - Quantity: 25 Seeds - Other: As You Can See, Hollyhocks Get Quite Tall, So They Are Right At Home In The Back Row Of Your Flower Garden. Their Tall Upright Stalks Are Covered From Top To Bottom With Endless Blooms In Stunning Shades. Every Summer, I Never Cease To Be Amazed At Their Loveliness Towering Over Me, And I Never Tire Of Watching The Bumble Bees Roll Around In Their Blooms Delighting In Being Covered In Pollen. Hollyhocks Are Easy To Grow, Grow Quickly, And Require Basically No Attention Once They Have Taken Off.