Some good old-fashioned shrubs are climbing their way back up the popularity ladder, and hydrangeas are making that comeback quickly and in epic proportions. Suddenly they don’t seem to be old and fuddy-duddy anymore. The value of having a reliable plant that blooms for months on end and is easy-care appeals to the time-poor. Being adaptable to sun and shade simply boosts their appeal.
Planting drifts of hydrangeas is an easy way of having a low-maintenance, colourful garden display for months on end. These hardy shrubs can be grown all over the country, from the hot and humid north right down to the cold and chilly south. With foliage and form, these gap-filling shrubs need more recognition.
Hydrangeas can be used in numerous ways:
- Planted under large trees.
- Blended into shrub borders.
- Planted along the shady cold side of the house.
- As patio and entranceway focal points. • In pots and containers, and even hanging baskets if you can find one big enough.
New dwarf hybrids are appearing every season, many of which are bred to cope with full sun as well as shade. This expands the areas in which they can be used in the garden. And it makes them ideal for growing in planters and large tubs.
Where and how to plant
Soil is the main thing to get right. Make sure it is well dug over before planting, blend on half a bucket of compost or manure and sprinkle in some general fertiliser. Nestle in the plant, firm the soil around it, then add a layer of mulch around the base to keep the soil cooler and weeds away. Dwarf varieties are perfect pot-plant specimens, and hanging baskets options. If you can find one big enough, in most areas you will have foliage for nine to 10 months of the year and flowers for about half of that.
Prune hydrangeas each season after flowering in June, July or August. Remove about 50% of the stem, down to a set of fat plump green buds, which will develop into next season’s flowers.
At pruning time, select some straight stems for cuttings. In a pot filled in potting mix or loose soil, insert these sticks until at least 50% is underground. In three to four months roots will begin to appear through the bottom of the pot.
Blue and pink hydrangeas
Hydrangea flower colours can change with different soil fertility. Many gardeners have been mystified by this as they may purchase a pink or red hydrangea in flower from the garden centre and find a year later, once it’s been in the garden a season, that the flowers have changed colour to a shade of mauve or blue. This is because flower colour is affected by the soil’s pH level.
Flower colour can be changed easily by adding either lime to enhance red and pinks, or using aluminium sulphate to change to blue. Changes should appear within a few weeks.
- Mop head
These are the big frilly-head hydrangeas, and probably the ones you associate with your grandparents’ garden. The heads can easily reach 30cm in diameter on older varieties.
- Lace cap
Pretty as a picture, the flowers on this type look like a lace tablecloth, with the large petals being arranged neatly around the outside of each flower.
- Pee Gee
These hydrangeas are glorious as the upright, almost cone-like flowers sit high above the foliage and come in various shades of white, cream, lime and now pink.
With large, thick, oak-shaped leaves that change colour from green through to shades of red and gold in autumn, the graceful, arching stems of creamy white single or double flowers are stunning.
These hydrangeas will cling to walls and fences with ease, growing up towards the light. They add a dramatic effect and are a brilliant way to hide an ugly façade.
Ones to seek
- Saxon ‘Red Dawn’
This stunning smaller-growing type has masses of rich darkpink, almost red flowers, which don’t seem to fade. It flowers for long periods and, due to its dwarf nature, is perfect for pots and containers on the patio or in your borders. It’s also a good option for attracting bees to the garden. In the North Island it is in all the Mitre 10s and in selected ones in the South Island. (It may pay to ring ahead if you live in the south.)
- Hydrangea paniculata
These forms are loved for their unfussy habit and unlike some other hydrangeas they prefer full sun. ‘Limelight’ is the top seller over recent years, but, in 2017, two new ones will appear, both of which will have pinkbased blooms – ‘Sundae Fraise’ and ‘Diamond Rouge’. ‘Levana’ is a delightful cream one with exceptionally large petals.
Yes, this is not a misprint, many of the newer hydrangeas have been bred to thrive indoors. Try to keep them away from the full sun inside; they are better in a slightly darker area as the light through the window can magnify and burn the flowers.
In a vase
Hydrangeas are top performers in a vase. Be sure to plunge them straight into water as soon as they are picked, especially if the stems are young. If the water is changed once a week, they can easily last a month.
What you need to know
When to plant
All year round.
Where to plant
Most prefer a site with some shade, however, new varieties have been developed which cope in sun or shade.
When to prune
After flowering in late autumn and winter.
1.5-2m between plants.