Common Questions About Hydrangeas

13 Jan Common Questions About Hydrangeas

Why is my blue hydrangea pink?                                                                                      hydrangea

If you purchase a pink hydrangea and it turns blue, your soil is acidic.  The color range depends on the soil, but the bluest shades are produced in the most acidic soils.  Not all hydrangea varieties will change color. Mophead and lacecap (macrophylla) cultivars which are available in pinks, blues and purples are affected by the pH of soil. However, varieties that produce white and cream flowers (smooth and oakleaf varieties) are not.

Test your soil pH to determine how alkaline or acidic your soil is. A range of 5.0 to 5.5 is acidic. As a result your hydrangea will bloom blue. Consequently, a pH range of 6.0 to 6.5 and higher is best for pink coloration. If you add garden lime to your soil it will raise the pH and keep your hydrangeas blooming pink. In contrast, adding soil acidifier to your soil will lower your pH and produce blue toned blooms.

Why aren’t my hydrangeas blooming?

Some hydrangeas bloom on the previous year’s growth. This is sometimes referred to as old-wood.  The old-wood is where the buds are that will open in the upcoming summer.  As a result, pruning these varieties in the winter or spring removes the buds. In contrast, other varieties bloom on new growth. Therefore, it is important to know which cultivar you have as pruning times vary.

Where can I grow hydrangeas?

There are four main groups of hydrangeas. Each variety has different growth requirements. Understanding how to care for the variety you have, will help you achieve optimal success.


The Four Main Groups


Big Leaf Hydrangeas – Hydrangea macrophylla

There are two main types in this group. The first is the mop head. It has big ball like blooms. The second is the lacecap which has a frilly, flatter bloom. Both types have large leaves. Blooms are pink, blue and purples and will change color depending on soil pH.

Water & Light – Big leaf hydrangeas prefer morning sun and afternoon shade. These types grow best in well drained soil and require lots of water.

Pruning – These plants bloom on old-wood. They should be pruned in late summer. Wait until they’ve finished blooming and you see new growth emerging at the base of the plant.


Smooth Hydrangeas – Hydrangea arborescens

This variety has a large, rounded bloom. They are generally available in white, pale pink or pale green. Smooth cultivars are cold tolerant.

Water & Light –  Varieties of smooth hydrangeas require a partly shaded location to thrive. They can tolerate some morning sun, but bright shade is best. Above all, they are extremely susceptible to drought.  Therefore, it is best to keep them evenly moist.

Pruning – These plants produce flowers on new growth. For that reason, it is best to cut them back to the ground in late winter or early spring. This will encourage blooms and help maintain them in a manageable size.


Panicle Hydrangeas – Hydrangea Paniculata

If you’re looking for an easy hydrangea, this is it. Panicles  are the easiest to grow. They produce large, showy blooms.  Blooms are greenish white and age to a beautiful pink as the season progresses. Furthermore, they are very hardy and extremely drought tolerate.

Water & Light – Panicles will tolerate full sun to part shade, but they bloom best in sun. They need to be watered well during the first season until they are established.

Pruning – This variety blooms on new growth. They can be pruned in winter or early spring. Although they don’t have to be pruned, pruning will stimulate flower production.


Oakleaf Hydrangeas – Hydrangea quercifolia

This variety has large, oak shaped leaves. It grows 6-8 feet tall and wide. Blooms are white or cream colored. Best of all, they produce vibrant fall color. Shades of yellow, burgundy and orange are displayed in autumn.

Water & Light – Oakleaf hydrangeas are drought tolerate. However, they thrive in moist soil. They require full sun to partial shade.

Pruning – Oakleaf varieties require very little pruning. They flower on old wood. Therefore, any pruning should be done after they’ve finished blooming in the summer. You can remove dead or damaged branches at any time.


Shipments of hydrangeas arrive throughout the spring and summer. Stop in and check out our selection


The staff at Bayview Garden Nurseries will be happy to assist you.

More about planting hydrangeas.

Stop in or call us. 609-641-0648.

We can answer all your hydrangea questions.