How to grow climbing hydrangeas

Choosing a climbing hydrangea

Climbing hydrangeas are very useful climbers for covering shady walls of fences and the attractive white flowers in early summer are a welcome bonus. They can also be also let to climb into medium to large trees. The deciduous

Deciduous refers to plants (mainly trees and shrubs) that lose their leaves seasonally, usually during autumn. This is a natural process triggered by the season's shorter days and lower temperatures and allows plants to conserve energy during the winter months. Hydrangea anomala subsp. petiolaris is hardy and easy to grow. Evergreen climbing hydrangeas Hydrangea seemannii and Hydrangea serratifolia offer an all-year-round interest, but they need to be grown in a warm, sheltered position to thrive. Though they are vigorous plants, to start with, they can be little slow. Climbing hydrangeas are not fussy about soil conditions, but they may struggle on excessively wet or chalky soils.

Buying a hydrangea

In garden centres, climbing hydrangeas can be found in the ‘climbing plants’ section. They are usually sold in 2-3 litre pots. Mail order plants may be smaller.

When to plant

Plant your climbing hydrangea soon after purchase. The best time to plant is in spring or autumn. Containerised plants can be planted all year round as long as the soil is not frozen, waterlogged

Describes soil or potting compost that is saturated with water. The water displaces air from the spaces between soil particles and plant roots can literally drown, unless they are adapted to growing in waterlogged conditions. Waterlogging is common on poorly drained soil or when heavy soil is compacted. , or excessively dry in summer.

Support

Though self-clinging, climbing hydrangeas usually need support such as wires or trellis to help them to get going. Tie in the new shoots until they form aerial roots that attach. Mature plants are heavy so start from the beginning with a sturdy support.

How to plant

• Water the pot well before planting
• If planting against wall or fence, allow about a 45cm (18in) gap between the plant and the wall. Otherwise, a 20-30cm (8in-1ft) gap is sufficient
• Make your planting hole as deep as the rootball
  The roots and accompanying soil when a plant is removed from a container or lifted from the ground. and three times wider
• The surface of the compost
  Can refer to either home-made garden compost or seed/potting compost: • Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own. in the pot should be level with the surrounding soil to avoid planting too deeply
• Firm in well
• Mulch
  Mulch is a layer of material, at least 5cm (2in) thick, applied to the soil surface in late autumn to late winter (Nov-Feb). It is used to provide frost protection, improve plant growth by adding nutrients or increasing organic matter content, reducing water loss from the soil, for decorative purposes and suppressing weeds. Examples include well-rotted garden compost and manure, chipped bark, gravel, grit and slate chippings. with soil improver
  Any substance dug into the soil to improve its structure. This is usually organic matter, such as well-rotted manure, garden compost or leafmould, but could be an inert substance such as lime or gypsum. to reduce drying out of the soil, but leave a 10-15cm (4-6in) gap around base
• Water in, using at least the equivalent of a large watering can of water

Training and pruning on planting

Where to plant

Ideally, plant your climbing hydrangea against a north- or east-facing wall or fence. A sunnier spot is fine, providing the soil doesn’t get too dry in summer. Evergreen Hydrangea seemannii and Hydrangea serratifolia need a sheltered spot as they are not fully hardy.

Though often slow growing to start with, they are vigorous climbers and one plant is sufficient to cover a house wall.

Watering

• Plants growing close to fences and walls tend to be in rain shadow receiving little rain, so keep an eye on their moisture levels and water in summer when dry
• Water newly planted climbing hydrangeas regularly during the first few of years when rain is lacking, from spring to summer, until fully established
• Reduce drying out of the soil by annual mulching
  Mulch is a layer of material, at least 5cm (2in) thick, applied to the soil surface in late autumn to late winter (Nov-Feb). It is used to provide frost protection, improve plant growth by adding nutrients or increasing organic matter content, reducing water loss from the soil, for decorative purposes and suppressing weeds. Examples include well-rotted garden compost and manure, chipped bark, gravel, grit and slate chippings. with organic matter, such as leaf mould, garden compost
  Can refer to either home-made garden compost or seed/potting compost: • Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own. or manure-based soil conditioner

Mulches and mulching

Feeding

• Regular feeding of established plants
  Established plants have been in their current location for two or three years and so have well-developed root systems able to support strong growth with healthy foliage and flowers. is not generally need unless they are struggling. However, poor growth may also be caused by soil dryness rather than lack of nutrients
  To grow well, plants need a wide range of nutrients in various amounts, depending on the individual plant and its stage of growth. The three key nutrients usually taken up from the soil are nitrogen, phosphorus and potassium. Plants also need carbon, oxygen and hydrogen to make carbohydrates — their main energy source. Carbon and oxygen come from the air as carbon dioxide, while hydrogen is drawn from water absorbed by the roots. Other important soil nutrients include magnesium, calcium and sulphur. Most garden soils contain enough of these nutrients to support healthy plant growth. and mulching and watering will be more helpful

Routine pruning

• Climbing hydrangeas produce flowers on last year’s shoots. To ensure that the plant have enough time to develop flowering wood for the next year, prune in summer straight after flowering
• Prune back the flowered shoots and shortening any overlong new growth
• Most flowers are formed towards the top of the plant, so try to leave as much of this un-pruned as possible or just lightly trim

Renovation pruning

• Hard pruning will reduce flowering for the next couple of summers
• Instead of severe reduction, consider renovation in stages over three or four years, reducing the size of the plant gradually
• Established plants
  Established plants have been in their current location for two or three years and so have well-developed root systems able to support strong growth with healthy foliage and flowers. will tolerate hard pruning in spring

Pruning climbing hydrangeas

They are easily propagated by layering.

Propagate from cuttings. Take softwood cuttings

Softwood cuttings are taken from spring to early summer (Apr-Jun), using material from the soft and flexible young shoot tips from this seasons growth, which root readily. Use for hardy and tender perennials, deciduous shrubs, climbers and some trees. from late spring to mid-summer, semi-ripe cuttings

A method of growing new plants from parts of an existing plant, such as sections of root, stem, leaf or bud. When prepared correctly and planted in the right conditions, they can produce roots and eventually become independent plants. There is a wide range of different methods for taking cuttings, depending on the plant and time of year. in mid-summer and or hardwood cuttings in winter

Cuttings: softwood

Cuttings: semi-ripe

Cuttings: hardwood

Species hydrangeas can also be propagated from seed in spring.

Lack of flowers can be caused by;

• Young plants often taking three to five years to start flowering
• Excessive summer pruning or pruning later in the season as the flowers are formed on the last year’s growth

Frost damage

Last year’s shoot tips can be damaged by hard frost. In spring, lightly trim back any badly damaged shoots.

Hydrangea scale

Most noticeable in early summer when stems and leaves are covered with white, waxy, flat ‘blobs’.

Hydrangea scale