Everything You Need to Know About Hydrangeas

Without hydrangeas, would summer as we know it exist? From Tokyo to Nantucket, their big, blowsy blooms are synonymous with warm nights and lazy days.

But don’t take hydrangeas for granted. With more than 75 species, the cheerful flowering shrub in your garden could be anything from a variety of H. arborescens (such as ‘Annabelle’, whose white pompom flowers are commonly seen along the American Eastern Seaboard) to H. macrophylla (a mophead native to Asia), or H. paniculata, with showy, cone-shaped flowers. There is even a climbing, vining hydrangea (Hydrangea petiolaris), which you can train to grow up a fence in a shady spot.

Are you planning to add a hydrangea (or three) to your garden? Wondering how best to arrange your showy snowball flowers in a vase? Or trying to figure out how to change the color of your pink hydrangeas to blue? We can help. Read on for tips and tricks for cohabiting with hydrangeas.

Photography by Takashi .M via Flickr.

Planting and Care Tips

Depending on the species and cultivar (of which there are hundreds), hydrangeas can live more than 50 years if they’re happy in the spot you select for them. There’s a hydrangea that will thrive in your garden if you live in USDA zones 2 to 9. To find the right hydrangea for your climate and growing conditions, see Hydrangeas: A Field Guide to Planting, Care & Design.

Favorite Varieties

From mopheads to oakleaves and climbing varieties, hydrangeas are available in a wide variety of sizes, colors, and shapes. Bewildered by the vast selection at your local nursery? We asked the experts to share their favorites—for a complete list, see 10 Best Hydrangeas to Grow.

Change Hydrangeas’ Flower Color

Hydrangeas can change color from blue to pink (or vice versa) depending on the acidity of the soil.  (The more alkaline the soil, the pinker the flowers.) Would you like to make your hydrangeas change color? See Hydrangeas: How to Change Color from Pink to Blue.

Wild, Untamed Hydrangeas

Hydrangeas in pots or too near the house can “look constrained, too neat,” writes our UK contributor Kendra Wilson. Her advice is to let them free. For ideas to encourage the wild, untamed look, see Landscaping 101: Wild Hydrangeas, 7 Ways.

Floral Arrangements

Hydrangeas make lovely, long-lasting cut flowers. For Justine’s tips on how to arrange them so they don’t look too fussy, see Bouquet of the Week: Hydrangeas Gone Wild.

How to Prune Hydrangeas

The question Barb Pierson, nursery manager at White Flower Farm in Morris, Connecticut, hears most often every year is: “When should I prune my hydrangeas? The answer depends entirely on the kind of hydrangea you have. See our recent sponsored post for A Master Class in Pruning Hydrangeas from White Flower Farm.

Shrubs in the City

Hydrangeas are tough, hardy shrubs that will grow in urban gardens where more fickle plants fail to thrive. See a romantic purple and blue thicket in New York City in My Garden Story: A Secret Rooftop Oasis on Manhattan’s Upper West Side.

Are you looking for companion plants for your hydrangeas? See shade lovers Astilbes 101 and Hostas 101 in our curated guides to Perennials. And if you’re looking for other flowering shrubs, start with our curated guide to Shrubs 101. Read more:

• The ‘Anti-Trophy’ Landscape: A Charming Country Garden in Columbia County, NY
• Lilacs: A Field Guide to Planting, Care & Design
• Container Gardening: 12 Shade-Loving Plants in My Backyard
• Get more growing and care tips at Hydrangeas: A Field Guide.