Most hydrangeas thrive in rich, porous, somewhat moist soils. Add compost to enrich poor soil. They prefer full sun in the morning, with some afternoon shade; however, many will grow and bloom in partial shade.Click to see full answer. Herein, how many hours of sunlight do hydrangeas need?The further north your garden is located, the more sunlight your hydrangeas need. An average rule of thumb is six hours of sunlight per day. However, hydrangeas growing in the south can perform on only three hours of sunlight. do hydrangeas need a lot of water? Hydrangea Plant Care: Water Requirements Hydrangeas absorb water quickly. Keep the soil of hydrangea plants evenly moist and well drained, though this can take watering your plants possibly more than once per day. Hydrangeas grown outdoors as shrubs and garden plants do not need as much attention to watering. Moreover, can hydrangeas be in sun? Most hydrangeas prefer only morning sun. Yet one type of hydrangea can soak up the sun all day: the panicle hydrangea. While they can stand the sun, these do just fine in partial shade, too. Here are the best hydrangea varieties to grow in full sun.Can I use Miracle Grow on hydrangeas?Gardeners who want robust and healthy hydrangeas must focus on providing enough sunshine and water for their plants. Hydrangeas also require fertilization to thrive; however, they don’t require special fertilization. All-purpose Miracle-Gro fertilizer is well suited for hydrangeas.