Hydrangea Flashcards
Cultivation notes
Hydrangeas thrive in a moist, but well-drained soil, in a cool, semi-shady part of the garden. Try to avoid exposed east-facing sites, where cold winds may damage young spring growth, and also avoid dry, sunny spots.
Work plenty of organic matter into the soil prior to planting, and after planting and in subsequent years apply organic matter as mulch. This could be well-rotted leafmould, garden compost, composted bark, or farmyard manure.
Hydrangeas can be fed annually if necessary with fertiliser in late winter or spring. This should be enough for the season, but should not be necessary on richer soils. On lighter, sandier soils, feeding is more likely to be helpful. Too much feeding can encourage excessive soft, leafy growth, with plants less likely to develop flower buds and more at risk from frost damage in colder winters
When to prune hydrangrageas
Most pruning is carried out in late winter or early spring. However, the climbing hydrangea is pruned after flowering in summer
Dead Heading Mopheads and Lacecaps Hydrangeas
Dead-heading
•Dead blooms on mophead hydrangeas can, in mild areas, be removed just after flowering, but it is best to leave them on the plant over winter to provide some frost protection for the tender growth buds below. Remove the dead flowerheads in early spring, cutting back the stem to the first strong, healthy pair of buds down from the faded bloom
•Lacecaps are hardier, and the faded flowerheads can be cut back after flowering to the second pair of leaves below the head in order to prevent seed developing, which saps energy from the plant
Pruning established mopheads and lacecaps
and renovation ?
Pruning established mopheads and lacecaps
•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
•Poor or neglected plants can be entirely renovated by cutting off all the stems at the base. However, this will remove all the flowers for that summer, and the new stems will not bloom until the following year
Pruning climbing hydrangeas
- The climbing hydrangea (H. anomala subsp. petiolaris) should have overlong shoots cut back immediately after flowering. Most flowers appear towards the top of the plant, so try to leave as much of this un-pruned as possible
- Established plants will tolerate hard pruning in spring, but extensive cutting back all in one go is likely to reduce flowering for the next couple of summers. To prevent flower loss, stagger drastic pruning over three or four years, reducing the size of the plant gradually
Pruning •Hydrangea serrata
Pruning Serrata
•Hydrangea serrata can be pruned in the same way as mophead and lacecap hydrangeas
Pruning Hydrangea paniculata and H. arborescens
Although the only essential work is to remove dead wood in spring, these species flower more prolifically when….
Although the only essential work is to remove dead wood in spring, these species flower more prolifically when pruned back annually to a framework of branches.
Each spring, cut back last year’s stems to a pair of healthy buds to maintain a permanent framework. To produce larger flower panicles on strong, upright branches, hard prune to the lowest pair of healthy buds, creating a low framework of branches. This usually results in a pruned framework of no more than 25cm (10in) high but, if more height is required, cut to about 60cm (2ft) tall
Problems
Problems
•If there is any frost damage in spring, prune back damaged shoots to just above the first undamaged pair of buds on live, healthy wood
•Also remove any weak, straggly stems. In particular, cut out any stems that trail onto the ground
Describe H. arborescens ‘Annabelle’
H. arborescens ‘Annabelle’ AGM: Deservedly popular cultivar with profuse spherical flowers to 30cm across opening greenish-white then aging to bright pure-white, from July to September. Height 1.2-1.5m (4-5ft).
The recent introduction. H. arborescens Invincibelle Spirit=’Ncha1’ has pink flowers
Describe H. paniculata ‘Limelight’
H. paniculata ‘Limelight’ AGM: Very dense flowerheads are white, flushed lime-green and then pink as the season progresses. Flowering from July to October, height 1.65m (5.5ft)
