how to plant, grow & care for hydrangeas

Hydrangeas are fantastic for lighting up a shady corner or the north face of a house, transforming what can be a really dull place into something full of life and colour. Flowers are very long-lasting and can even be dried and brought indoors. There are a wide range of varieties available, including traditional mop heads and lace caps (H. macrophylla), elegant shrubby species such as H. paniculata, H. arborescens and H. aspera and also the invaluable climbing type (H. anomala subsp. petiolaris). Browse our range of hydrangea plants and fill your home and garden with beautiful blooms.

details

  • Common name Hydrangea
  • Latin name Hydrangea
  • Type Shrubs & climbers
  • Height 60cm-4m high and wide (or 6m for climbers)
  • TLC rating Easy
  • Aspect Part shade
  • Planting position Borders or containers
  • Suitable for pots Some smaller varieties
  • Good for pollinators Some (climbing hydrangeas and some paniculata types)
  • Good for cut flowers Yes

calendar

JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
Sow Under Cover/Plant Indoors
Direct Sow/Plant Outdoors
Flowers/Harvest

how to grow hydrangeas

where to grow hydrangeas

Soil type: Grow hydrangeas in moist, fertile soil. They are also happy in clay.


Aspect & position: Plant hydrangeas in a cool, semi-shady part of the garden, avoiding exposed east-facing sites where cold winds can damage young spring growth. 


when to plant hydrangeas

Hydrangeas can be planted year-round but for best results plant them in autumn or spring when the ground is moist and not frozen.


how to plant hydrangeas

planting hydrangeas

Allow enough space for your hydrangea plants to reach their full width (60cm to 4m depending on type) and work plenty of organic matter into the soil prior to planting.

planting climbing hydrangeas

Plant climbing species at the foot of a wall or fence, at least 60cm out so that rainwater can reach the roots. They may need to be guided against the wall or fence initially but will soon produce aerial roots that cling.

planting hydrangeas in pots

Smaller varieties such as 'Little Lime' can be grown in pots but will need soil-based compost and very regular watering as well as occasional feeding in summer.


how to care for hydrangeas

feeding & watering

Water newly planted plants in dry spells. Mulch in autumn to help conserve moisture. Established plants should have deep root systems that find water in summer, but you can water thoroughly once a week if needed during prolonged dry spells in summer.

pruning

Prune shrubby hydrangeas in March; climbing ones in July or August, after flowering.

H. arborescens and paniculata
Remove any dead, damaged, diseased or crossing branches in early spring. Once established, cut back last year’s stems to within one or two buds of the older woody framework, to encourage more prolific flowering. By cutting stems to different heights, you’ll get flowerheads produced at different levels.

H. macrophylla
Remove the dead flowerheads in early spring, cutting back to the uppermost pair of strong, healthy buds. Once established cut out one or two of the oldest stems at the base to encourage the production of new, replacement growth that will be more floriferous.

H. aspera
This needs very little pruning and in most cases is best left to its own devices for maximum flowering. They do not send out vigorous shoots that need curbing. Remove diseased, damaged, congested or crossing shoots. Shoots that are growing in unwanted directions can also be pruned out. 

H. petiolaris
Prune immediately after flowering to shorten any branches growing out from the wall, otherwise only light pruning is required to remove dead or damaged stems.

seasonal checklist

spring

  • Prune all hydrangeas, except for climbing types, in the spring.


summer

  • Water newly-planted and containerised hydrangeas in dry spells. 
  • Prune climbing types after flowering.

autumn

  • Mulch around the base of plants.
  • Pick some heads for the house.

winter

  • Hold off pruning your hydrangea plants until the end of winter.

pests, diseases & common issues

scale insect

Hydrangeas are prone to scale insect. These are small brown insects which cling to stems (looking like raised lumps) and lay eggs covered in a white waxy substance. A few insects should not affect the health of the plant but if they seem to be weakening it you can try rubbing them off by hand.

frost

New shoots can be blackened by frost in spring. Leaving the branches unpruned with their dried heads on until March can help to protect the green buds below. If new shoots do get hit by late frosts simply trim them back to just above the first pair of healthy buds.

why are the leaves on my hydrangea turning yellow?

Leaves change colour in autumn as the plant begins to go dormant. If your hydrangea is turning yellow or brown or losing its leaves in spring or summer, there is probably something wrong with the roots. They may be too dry, have been damaged or have a disease. Sometimes if the leaves go bright yellow (often with green veins) there is a nutrient deficiency. This can be caused by very poor, dry soil so water well and give a liquid feed.

why is my hydrangea not flowering?

Sometimes young plants take a year to settle down before flowering. If a more mature plant doesn’t flower it may be because it was pruned too hard or at the wrong time or it got very dry. Don’t hard-prune macrophyllas and avoid high nitrogen fertilizers which can lead to lots of leafy growth and fewer flowers.


frequently asked questions


when do you prune hydrangeas? 

Prune all shrubby hydrangeas in March; climbing ones straight after flowering in July or August.


how to prune hydrangeas?

The main thing is to trim off spent flowers, cutting each stem back to a strong healthy pair of green buds. See the ‘how to care for hydrangeas’ section above for more information about how to prune specific types.


why has my blue hydrangea turned pink?

Some mophead hydrangeas have blue flowers when they are growing in an acidic soil and pink when they are growing in a more alkaline soil. If you live in an area where there is lime in the soil and you want to grow a blue hydrangea, it may be best to keep it in a pot. There are some plant foods to help keep them blue, but these rarely work in the long term.


how to propagate hydrangeas?

You can take cuttings from fleshy green stems in late spring and summer or from brown woody stems in winter. Keep them in a sheltered, shady place in moist compost. It will be two or three years before they will be flowering plants.


when to deadhead hydrangeas?

It’s best not to deadhead hydrangeas until early spring when you prune them. You can of course pick a few before then if you want to have them in the house during autumn and winter.


when to move a hydrangea?

Small or newly-planted hydrangeas can be moved from October to March, provided the soil is moist but not frozen. It’s best not to move large, well-established plants. If you must move them, cut them down first and dig the biggest hole possible and be prepared for them to take a few years to recover.

what to grow with hydrangeas

Hydrangeas look great underplanted with shade-tolerant perennials such as pulmonaria, epimedium and Geranium macrorrhizum which flower in spring and early summer before the hydrangeas get going.

how to cut & arrange hydrangeas

Pick the flowers on a dry day. Don’t choose new blooms but instead look for ones that are fully open, firm and slightly papery. If it’s a white variety with blooms that turn pink as they mature, they should have begun to turn a little pink already. Strip off the leaves and cut the stem on an angle. You can also cut a little way up the woody stem or sear it in boiling water for a minute. Place the stems in a tall vase with about 3 cm of water in it (you can also add glycerine). Leave in a cool, well-ventilated room out of direct sunlight. Once the water is used up the stems will last for several months and can be used in arrangements including wreaths.


Get more inspiration for displaying your flowers with our flower arranging videos and articles:


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