The creativeness of a creative woman
This is the first of several posts on the topic of Hydrangeas. To say the information is vast and there are 100’s of different types is an understatement. In an effort to streamline the information I’ve decided to dedicate one post on the types available at local garden centers (or via mail); one post to the care and maintenance of Hydrangeas; and another post on maintaining and/or changing the pH of your soil.
There are tons of sites on the internet providing all kinds of information. As I was going through site after site I did notice that most concentrate on a particular topic (color, soil, cuttings, etc..) but none really provide a complete “one-stop” shop (so to speak) of detailed information. I am going to attempt to provide as much information as I can without getting too deep into details that mainly horticultural professionals must know; yet provide enough information to give you a clear understanding of what, how, when, etc…. There is much more to Hydrangeas than acidic soil produces blue flowers while alkaline soil produces pink. It’s not Black and White……there are several shades of Gray or in the instances of Hydrangeas, several shades between Blue and Pink. With that being said, the varieties now available on the market have been cultivated so even the novice gardener can grow Hydrangeas. It’s the extra time and care that determines if it will last for years and be a stunning specimen in your yard or garden.
Types of Hydrangeas
Hydrangea Macrophlla – The most common form of Hydrangea and the type typically found in garden centers. The Macrophylla hydrangeas have the distinction of being variable in color; those which are not pure white will color in the blue spectrum under acid growing conditions when aluminum is present in the soil, and into the red spectrum in neutral or alkaline soils. This mutability of color can cause a plant to produce blue flowers one year and pink the next, and tends to result in a wide spectrum of colors from purple to blue to red to blush pink. The color variants can be exquisite, but also fleeting; stabilizing good blues and rich pinks is usually easy, but stabilizing a particularly beautiful shade of mauve or purple very difficult. Some cultivars more readily assume shades of purple or violet, and others regularly tint toward burgundy or crimson. Orange reds have eluded the breeders, as well as yellows, apricots, flames, etc.
Most Macrophyllas thrive in soils that are regularly watered, of average fertility, and in locations of very bright filtered light or morning sun followed by shade. Many will tolerate the cold in zone 6 with some shelter, though only those capable of re-bloom are likely to flower well. Extreme summer heat stresses these plants and often ruins their flowers. Plants are fast growing, but range from very dwarf to very large in size.
There are two types of Macrophlla:
The Mophead has great appeal, in part because so much more color is produced on the plant. A heavily blooming Mophead hydrangea can be so covered with florets that most of the plant’s foliage is obscured. The additional large florets also lend to the flower head a tendency to dry effectively so that the floral form is preserved. This has led to the popularity of the Mophead hydrangea as a dried flower. Those which color well often retain much of the brilliance of their fresh flowers when air-dried, and many dry naturally on the plants, their colors aging to beautiful antique shades of purple, copper, bronze, mahogany and green. Many white-flowered mopheads mature to pale shades of green.
Lacecap hydrangeas have been known to sport mutant branches that exhibit the mophead floral form, and Mopheads have been known to revert to the Lacecap form. The only real distinction between the two groups is the form of the flower panicles.
Hydrangea paniculata – A floriferous species with handsome, matte green foliage, paler on the reverse, often smooth and shiny in the fresh flush of new growth. It blooms on the current year’s growth and can be pruned hard to produce larger flower panicles. These clusters of white blossoms are wide at the base and taper to a blunt point. Here in America the commonly grown form is Grandiflora, (resembling a mophead). But the wild forms, of which many now exist in gardens, combine large and small flowers in a mixed head that is also conical in outline. Many wild-collected forms like ‘Kyushu’ have flower heads that are very elegantly elongated and include small, bright green leaves within the inflorescence.
This is one of the Mountain hydrangeas originally cultivated in Japan that flourishes best in full sun. In warmer climates it may be useful to plant these where they will receive filtered shade at the hottest part of the day or in the afternoon, as the flowers will last longer and color more handsomely for later drying. Paniculata has many excellent attributes apart from its love of sun. It is late blooming and provides a superb addition to the late summer garden. It blooms on new wood so it can be kept smaller or allowed to build into the large, graceful shrub which is so admired. The flowers gradually age with pink and burgundy tints, making it a favorite for flower arrangements. They are recommended for colder climates and perform better than many other Hydrangea species in the zones of 5 and 6. Because of their large flower heads and tall growth they can be easily damaged by wind, so it is best to plant them in a sheltered location.
Paniculata ‘Grandiflora’ is a treasured heirloom plant, as it has been grown in European and American gardens since the 1860s.
Hydrangea quercifolia (Oak Leaved Hydrangea) – Native to the Southeastern US, Hydrangea quercifolia was first recorded in the early nineteenth century. A number of unusual and very beautiful forms have been discovered as chance seedlings in the wild. In recent years these showy plants have seen a renaissance of interest by America gardeners.
Quercifolia are medium to large shrubs with long, tapered panicles of white flowers, large, often rugose foliage, deeply lobed like oak leaves which turns deep burgundy-crimson in the autumn. Many elegant forms including mophead types were found in the wild in the twentieth century. This type can have very full flower panicles that hang vertically downward under their own weight, like heavy clusters of white grapes. The dwarf Oak-Leaved forms with many small florets have a notable fragrance of a honey-like perfume.
Hydrangea serrata – Botanically this a subspecies of Hydrangea macrophylla, and there are three species lumped into this one subspecies; H. japonica, H. Thunbergii, and H. accuminata. All have the physical distinctions of slender stems, extra-hardiness and color-changeable flowers of H. accuminata, flowers that turn from white to read and invert in H. japonica, and the very small stature and red tinted stems of H. thunbergii.
The Serratas are a mixed batch. They have come to Western gardens in the form of selected or improved forms, and perhaps hybrids among subspecies, but not as simple, pure, wild forms. Their existence in Japanese gardens long before they were grown in Europe or America assured this.
Serratas are generally small to moderate in size and grow best in filtered shade, though morning sun will tint the leaves and flowers of many adding to the attractiveness of the specimen. These are the woodland Hydrangeas found throughout the islands of Japan, with a simple delicacy and association with Japanese culture.
Many Serratas have flowers that will tint either pinkish or blue depending on the soil conditions, just like the Macrophyllas, but some are not so influenced. Those derived from H. Japonica are white upon opening and become blotched and blushed with red, eventually coloring deep pink or red and turning upside down as they age.
Hydrangea arborescens – This easily-cultivated group of hydrangeas have been culled from the wild here in the United States, principally in the East and Midwest. It is the hardiest group of hydrangeas, accepting the very coldest continental climates, but thriving in mild-winter areas, and even in humid, hot-summer climates. The Arborescens group, typified by the striking, wild sub-species H. arborescens ‘Radiata’, are slender stemmed, suckering shrubs rather like woody, overly large perennials. They can be pruned to the ground in winter, and will bloom with fewer, but very large flower heads on new growth.
They are often most attractive where allowed to grow freely. Arborescens can develop into shrubs of moderate size with an abundance of crowded panicles of flowers, which start green, turn cream, fade to white and age green again. Those with lots of sterile florets can be dried very effectively, either green or off-white, and will age to beautiful shades of mahogany and tan if allowed to finish naturally on the plants. The Arborescens can be grown in full sun but the flowers are far longer lasting if located in an area with afternoon shade. Very shaded conditions are not always to their liking.