For many years, my grade 8 graduating classes would spruce up the school’s gymnasium with buckets of mopheads.
Not the kind that was found in the janitor’s storeroom but those huge floppy blossoms that are found at this time of year in many traditional gardens.
According to the Farmer’s Almanac, these mopheads are “Unrivaled in the shrub world, these elegant ladies are easy to cultivate, tolerate almost any soil, and produce flowers in mid-summer through fall.”
Of course the term “mopheads” is the common name for the botanical, hydrangea.
The shrub is tolerant to zone 3 – 9. It is a superb choice for all garden situations.
The word hydrangea is from the Greek, hydro, meaning water, and angeion, meaning vessel.
The plant is part of the saxifrage family group. More than 30 varieties grow in North America and Asia.
At a meeting of the Fergus Horticultural Society, Kathy Granger, master gardener enthralled members with a slide presentation highlighting various cultivators of hydrangeas.
Granger focused on the shrub’s general care and overall requirements for stunning blooms year after year. Like with all shrubs, a regiment of general care is necessary for the plant to continue performing.
Granger said to “remove the old inflorescences by late winter or sooner if they become unsightly, but before the new leaves show.”
Inflorescence refers to a cluster of blossoms on a stem that is made up of a branch or an intricate arrangement of branches. The term is also reserved for the reproductive part of the plant that has a cluster of flowers, usually in a pattern.
“Be careful not to damage tender growth, as the new floral show depends on the maturation of the entire shoot,” cautioned Granger.
“If stems are cut to the ground, new shoots will produce larger flowers. The more vigorous the shoot growth, the larger the inflorescence will be.
Do not over fertilize – lush growth is susceptible to powdery mildew and other diseases.
The leaves are frost resistant but will not provide much fall colour.
The plant prefers full sun but will grow in filtered shade. Once established, no special watering is needed.
They grow happily under pines because they like soil on the acidic side”, continued Granger.
“The most common cultivars are Grandiflora and Annabelle,” said Granger.
“Grandiflora can be long-lived and is sold in vast amounts every year. Sepals emerge apple green, mature to white, fade to parchment brown and remain attached all fall and winter.
“Colours usually peek in early – mid June. Fertile flowers can be fragrant. Annabelle is self fertile –meaning pollen from the same flower will pollinate the female flower and produce viable seeds,” said Granger. “The colour [whites, pinks, blues, lavender, rose] of some flowers is affected by the relative availability of aluminum ions in the soil. Acidic soils with a pH of less than 5.5 produce blue flowers; soils with a pH greater than 5.5 product pink flowers. White flowers are not affected by pH,” informed Granger.
“It is possible to change the flowers’ colors but not instantly. Colour correction takes weeks, even months.
“It is easier to change blue flowers to pink than pink to blue. Wait until the plant is at least two years old to give it time to recover from the shock of its original planting,” instructed Granger.
Most hydrangeas thrive in rich, porous, somewhat moist soils. Add compost to enrich poor soil. When planting or transplanting, dig a hole as deep as the root ball and twice as wide. Set the plant in and fill it half full with soil and compost. Water generously until it has fully drained off. Fill the hole with soil. During the first years water thoroughly until it becomes established, keeping an eye on the leaves to see if additional watering is necessary. Space multiple plantings a metre apart.
Ron Stevenson is a member of the Fergus Horticultural Society
