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Everything You Need to Know About Endless Summer Hydrangeas

Endless Summer Hydrangeas live up to their name, blooming massive pink or blue mophead flowers on both old and new wood all summer long.

Summer Hydrangeas Adobe

Endless Summer Hydrangeas are unique, taking the traditional hydrangea to the next level. They can grow their enormous, bold flowers on both old and new wood—making for an exceedingly long blooming season and the potential for reblooms. You can even customize your Endless Summer Hydrangea, adjusting the soil pH to yield either vivid blue, pale lavender, soft mauve, or deep pink mophead blooms.

As a cold-hardy specimen, Endless Summer Hydrangeas can even tolerate frost—making them ideal for gardens beyond the South.

Endless Summer Hydrangeas at a Glance

  • Bloom on both old and new wood
  • Flowers can be pink or blue
  • Cold hardy
  • Long blooming period from summer to fall
  • Can be grown in a container
  • Prefer partial shade in warmer climates

Appearance

The Endless Summer Hydrangea is a shrub, growing in a rounded shape. Its dark green leaves range from 4-8 inches long, and its stunning blooms are showy mopheads nearly 8-10 inches in diameter.

You can choose from a range of colors, depending on the alkalinity or acidity of your soil. Shades range from deep blue to light lavender to soft mauve to vivid pink. The more acid the soil, the bluer, and the more alkaline the soil, the pinker the flowers are.

Endless Summer Hydrangeas are compact, growing 3-4 feet tall with a 3-4 foot spread.

Specifications

Appearance Rounded shape with dark green, serrate, obovate to elliptical leaves. Massive mophead flowers that can be either blue, pink, or in between
Appearance Rounded shape with dark green, serrate, obovate to elliptical leaves. Massive mophead flowers that can be either blue, pink, or in between
Height 3-4 feet tall
Hardiness Zones Zones 4-8
Type of tree Deciduous shrub
Sunlight requirements Partial shade
Soil composition Well-drained and moist. Can grow in range of alkaline to acidic soils

Hardiness Zones

USDA Hardiness Zones indicate the regions where plants can grow based on minimum winter temperatures. Endless Summer Hydrangeas grow in Zones 4-8, able to thrive in more parts of the country than other hydrangea varieties. They are cold-hardy enough to withstand frost and can tolerate some heat. However, in warmer climates, they should receive minimal afternoon sun.

Planting

Fall or early spring are the best times to plant Endless Summer Hydrangeas. You want to give them time to establish a healthy root system before the blooming season begins.

Choose a sheltered planting site that receives partial shade—ideally, sun in the mornings and shade in the afternoon.

Before planting, decide what color Endless Summer Hydrangea blossoms you want. For bluer blossoms, you can amend your soil with sulfur. If you’re more interested in bold pinks, amend it with lime.

Dig a hole twice the width of your Endless Summer root ball and roughly its depth. You want your plant to be just slightly higher than the level of the surrounding soil.

Begin to backfill the hole with soil. Stop halfway and pour water into the hole until it rises to the top. Once it drains away, finish filling in the rest of the soil.

If you’re planting your Endless Summer Hydrangeas as foundation plants, space them eight feet apart from each other from the center. For a garden border, space them out four feet apart.

Growing Conditions

Endless Summer Hydrangeas actually enjoy partial shade to full sun and are able to bloom on both old and new growth from spring through summer or early summer to fall, depending on the climate you live in.

Sun and shade

Endless Summer Hydrangeas thrive in partial shade, or roughly four hours of direct, unfiltered sunlight per day. It’s best if they receive sun in the morning and shade in the afternoon.

Soil

Endless Summer Hydrangeas can grow in a range of soils but need moisture to flourish. The key thing to remember about soil is that the level of acidity or alkalinity will determine the color—from blue to purple to pink. For a bluer shade, make sure your soil is acidic. For pinker, amend it to more alkaline, as needed.

Watering

You should water your Endless Summer Hydrangea routinely each week, up to twice a week during the hotter months.

Fertilizing

Fertilize your Endless Summer Hydrangea once in spring or summer with a specially formulated fertilizer. Slow-release fertilizer is encouraged, but a fast-release balanced fertilizer with an NPK value of 10-10-10 will also work.

Pruning

You do not have to prune your Endless Summer Hydrangea, because they can bloom on both old and new growth. But you should trim any dead, dying, or diseased branches when you notice them.

Frequently Asked Questions

Why are my Endless Summer Hydrangeas not blooming?

Over-pruning is a common reason for why Endless Summer Hydrangeas are not blooming. They bloom on both old and new growth, so they do not require pruning unless there are dead, dying, or diseased branches.

What zones can you grow them in?

You can grow Endless Summer Hydrangeas in Zones 4-8

Do they need sun?

Endless Summer Hydrangeas prefer partial shade, with about four hours of direct, unfiltered sun in the morning followed by afternoon shade.

Do they bloom on old or new wood?

Endless Summer Hydrangeas can bloom on both old and new wood, making them a rarity among hydrangeas.

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