KC Gardens

Two more articles about hydrangeas


Panicle hydrangeas

Mention the word hydrangea and most people conjure up the quintessential image of a round, billowing head covered with soft pastel pink or blue flowers.

Over the years, this familiar image has become the poster child for hydrangeas. What if I told you that your garden could be loaded with hydrangea summer color, but without all the fuss? Beautiful flowering hydrangeas can easily grace your garden. But it requires a change in that long-held pastel impression in order to achieve the greatest success with hydrangea in a Kansas City garden.

Hydrangea macrophylla are the typical blue or pink hydrangeas that get planted most often. While they might have the most desirable flower color, they are also the hardest to grow. The problem with these plants is that older varieties bloom on old wood, which often winterkills here in KC, and results in no flowers. The newer cultivar Endless Summer blooms on new wood. But it does not tolerate our droughts and is often referred to as a “water hog.” Most people that have tried growing them here are underwhelmed by its performance.

The hydrangea that should be in just about every garden in Kansas City is much more adaptable to the pendulum swings in our weather patterns. One of the best hydrangeas for local gardens is often referred to as panicle hydrangea, or known botanically as Hydrangea paniculata.

Panicle hydrangeas bloom on new wood produced during the current growing season. They are easier to prune and have no issues with winter bud damage. The flower buds are formed at the terminals of the limbs produced during the spring and summer. In fact, pruning can be as simple as cutting the plant back to the ground each spring, if you wish to control its size and create a smaller bush. Some varieties will reach 6 to 8 feet if allowed to grow.

This group of hydrangeas all flower white, with some slight variations. The flowers normally start out white and then fade to very light shades of pink or lime green, depending on the variety. Flowers start appearing around mid-July and peak in early August, with color lasting well into the fall. The flowers are a bright spot in what is normally the hottest, driest part of summer.

As with most garden plants, panicle hydrangeas do best in evenly moist soil, and will tolerate our heavy clay soils if given good drainage. They are happiest and most vigorous in soils which have been prepared with organic matter.

Panicle hydrangeas are more drought tolerant than other hydrangeas. The nice thing about this group is that they will quickly tell you when it is time to water, as they wilt under dry conditions. Provide them water on a regular and timely basis and the plants will thrive. Plants that are limited on water will often scorch if in afternoon sun and the flowers will be smaller than desired.

Sunshine is not a problem, as this grouping of plants often puts on its best floral display in either full or almost full sun. They can be grown in a shady location, but this will result in smaller flower size, and the display is less spectacular. But on the other hand, plantings in the shade provide summer color, as there are not many other options for summer blooming shade plants to lighten up a garden.

Recently, a number of panicle hydrangeas have been released on the market, as this plant continues to grow in popularity. The original variety is Grandiflora, which is commonly referred to as PeeGee. This plant produces large white flowers, which unfortunately can droop, as they are so large and heavy when in full bloom. This plant is also commonly sold as a standard, or tree form. When grown as a small tree it has a rounded to umbrella shape, and droops with flowers.

Tardiva is another great older variety. The variety credited for bringing this plant into the gardening mainstream has to be Limelight. Limelight starts out white and then turns a bright lime green shade, which last for months in the garden. Other varieties commonly found on the market include such favorites as Little Lamb, which instead of the potential height of 6 to 8 feet will top out around 3 to 5 feet, making it a better fit in smaller gardens. Another smaller variety is a small version of Limelight appropriately named Little Lime.

Paniculata hydrangeas breeders have been attempting to introduce more color into the white flower. Thus, several varieties are now available that tend to pick up shades of very light pink as the flowers age. Varieties that tend to have this characteristic include Pinky Winky, Vanilla Strawberry and Tickled Pink.

Hopefully by now, you will agree that just about every garden needs a panicle hydrangea. I guarantee that no other shrub will provide as much summer flower power with so little care. Spring is the best time to plant. But now is a great time to survey the garden and start planning for this new addition next spring.

Oakleaf hydrangeas

Gardeners are always on the lookout for the next bigger and better plant to grace our gardens. I often find that like many things in life the “best” is right under our nose, but we “can’t see the forest for the trees,” to use an old metaphor. That is how I was with this shrub until Extension Master Gardener volunteers added it to our demonstration garden. This tried and true plant that desires a spot in all area landscapes and gardens is oakleaf hydrangea.

Hydrangea quercifolia, or common name oakleaf hydrangea, is truly one of those rare, four season plants that puts on a spectacular show all year round.

Spring starts the show with beautiful white flower clusters that cover the plant. The flower period is long for a flowering shrub, lasting two to four weeks. Once the peak display has passed the faded flowers still have character. The flower clusters transform from pure white to pink hues. Eventually, the clusters dry to a nice creamy bronze that creates interest for the rest of the summer and into fall.

Summer finds this multi-season plant cloaked with large green, leathery textured leaves. The leaf shape is interesting, as they are deeply lobed giving them more the look of an oak, hence the name oakleaf hydrangea.

Fall is this plant’s season to really shine, as the leaf color is some of the best around. Oakleaf hydrangeas slowly change from the deep green to the prized and coveted shades. Fall color ranges with the variety, but picture a stately shrub in the landscape that glows with shades of wine-red to purple and rich burgundy for weeks. These fall hues are not muddy but clear and bold, which are exceptionally striking when the sun backlights a leaf.

Winter brings with its arrival another feature of this plant. Once the leaves drop the inner-beauty of the plant is revealed. Young branches are a nice brownish color. As the stems age the bark begins to exfoliate or peal, developing a rich cinnamon-brown papery appearance. The combination of reddish-brown looks great all winter long, but is most showy when snow blankets the ground.

Here is the best part about this four season plant, it’s not a diva. Oakleaf hydrangea is adaptable but prefers morning sun with light shade in the afternoon. It will tolerate more sun but will need to be kept evenly moist for best growth. It will tolerate some shade and still flower. The plant will thrive best with supplemental moisture during dry spells but can be quite drought tolerant once established.

Oakleaf hydrangea, if situated correctly in the landscape, will require little pruning. It flowers on old wood so do not prune until after it blooms. Because it does flower on old wood there is little concern about winter hardiness of the buds, unlike the more demanding Hydrangea macrophylla types.

The other good news about this plant is the availability of several varieties, some larger and many more tailored to today’s smaller yards. ‘Alice’ may be the largest of this grouping, reaching upwards to 10 feet and features extremely large flowers and a great wine-red to purple fall color.

‘Snowflake’ will range in height from 6 to 8 feet, and its unique feature is double flower blossoms which are quite attractive. This oakleaf hydrangea may be the best for shady areas, as it is not as adaptable to the sun.

‘Snow Queen’ may be one of the more sun tolerant varieties and reaches up to 4 to 6 feet tall. The flowers also tend to be held more upright instead of horizontal as with many other varieties. Fall color is a deep red-bronze.

‘Sikes Dwarf’ is smaller; growing only to 4 feet but still retains all the great qualities of its larger cousin. Great summer foliage is followed up by the impressive red to purple fall color. Another one reaching the same size is ‘Vaughn’s Lillie.’ Its attribute is the fact that it might have the largest flower head in comparison to size.

The smallest of the many selections, only growing to 2 or 3 feet, is called appropriately ‘Pee Wee.’ Expect smaller size flower clusters, but just think how adaptable a plant this size is in the landscape, with great flower color in later spring.

As you can easily see, oakleaf hydrangea deserves a place in every landscape setting. It is truly one of those plants that are pleasing to the eye in all seasons.


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