How to grow shrubby willows

Choosing a shrubby willow

There is a wide range of shrubby willows to chose from, often with vibrant winter shoots in various colours and attractive spring catkins. They add interest early in the season, making them a useful addition to many gardens, as long as you have enough space and suitable growing conditions:

• Most grow best in full sun, in moist soil that does not dry out, so check you have the right growing conditions before buying.
• These willows often grow quite large, so make sure you have space for their eventual size. Some can be kept smaller by pruning hard (coppicing) every spring, which may encourage colourful winter stems.
• A few are smaller, and some can even be grown in containers. However, even diminutive willows can be wide spreading, so always check eventual height and spread before buying, to make sure you have space for future growth.

Your range of choices includes:

• Salix gracilistyla ‘Mount Aso’ has fluffy pink catkins and grows to 3m (10ft) tall
• S. irrorata (blue-stemmed willow) with fluffy grey catkins with red anthers, it reaches 3m (10ft) tall
• S. alba var. vitellina ‘Yelverton’ has orange-red winter shoots and can reach 2.5m (8ft) tall
• S. lanata with white woolly stems and silvery-green catkins, it reaches 1.5m (5ft) tall
• S. ‘Mark Postill’ with silvery catkins, grows to 90cm (3ft) tall

Around 20 Salix species and cultivars have an RHS Award of Garden Merit, which shows they performed well in RHS trials, so are reliable choices.

To browse photos and descriptions of shrubby willows, go to RHS Find a Plant, where you can also narrow down your search by height and spread, growing conditions and RHS Award of Garden Merit.

You may also be able to visit the UK National Willow Collection at Rothamstead Research (Harpenden in Hertfordshire), to see the wide range of species it grows. Its website includes a list of willow species and cultivars and their stem colours.

How and what to buy

Shrubby willows are widely available all year round in garden centres, nurseries and online by mail order. You can buy them in a range of plant and pot sizes, at a corresponding range of prices. To track down specific cultivars, go to RHS Find a Plant.

How to choose healthy plants

Buying: trees and shrubs

When to plant

You can plant shrubby willows from autumn to early spring, whenever the ground is not frozen. However, autumn planting is recommended, because it allows them to establish their roots over winter. They will need less watering than if planted at warmer times of the year.

Where to plant

In borders:

• Choose a site with full sun or a little light shade and soil that stays moist in summer
• Shrubby willows need plenty of space to spread, so choose a spot that will suit the eventual size of your plant
• You can improve moisture retention before planting by digging in a bucketful of well-rotted 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.

  , leafmould or manure into the planting area
• Take care to plant container-grown shrubs at the same depth they were growing in the pot
• Willows are tough and fully hardy, so can be planted in frost pockets or on particularly cold sites
• Avoid planting large shrubby willows near building foundations or underground pipes, especially in shrinkable clay soil, as they have an extensive, vigorous root system that can take up a lot of water

Trees near buildings

In containers:

• For short-term planting in containers, use a peat-free multipurpose potting compost
• For permanent planting, use a loam-based compost, such as John Innes No. 2 with added coarse grit to improve drainage
• Replenish nutrient levels by adding controlled-release fertiliser when planting, repotting or top-dressing
• Water frequently during the growing season
  

  The period of time when an individual plant is in active growth. This will depend on the local climate and light levels, and can vary between different plants, although it is broadly from spring to autumn.

  if the weather is dry and hot

How to plant

Willow trees are easy to plant, and should be planted as soon as possible after buying – simply follow our planting guides below.

How to plant a shrub

Growing plants in containers

Watering

• Water newly planted willows regularly for the first two or three summers, especially if the soil is not reliably moist during hot, dry spells
• To avoid unnecessary watering, check if the soil feels dry at a depth of about 15cm (6in), and if so, water generously, allowing it to soak in well
• Once well established, shrubby willows shouldn’t need watering when grown in the type of soil they prefer – moisture retentive but free draining
• Plants in containers usually need regular watering throughout the growing season
  

  The period of time when an individual plant is in active growth. This will depend on the local climate and light levels, and can vary between different plants, although it is broadly from spring to autumn.

Collecting, storing and reusing water

Feeding and mulching

• Most shrubby willows are robust and vigorous and shouldn’t need feeding unless they are showing signs of nutrient deficiencies
• Mulching around the base of the shrub with well-rotted organic matter, such as garden compost or farmyard manure, will help to improve the soil’s ability to hold water and will provide 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.

  as it rots down
• Apply a 5cm (2in) thick layer of 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.

  as the soil warms in early to mid-spring. It will help to deter weed germination
  

  Germination is the process by which a seed develops into a new plant. It starts with the seed coat absorbing water, expanding and splitting, which allows oxygen and water into the seed so its food reserves can be broken down and used by the embryo for growth. The first root (called the radicle) pushes into the soil to anchor the new plant in place and start absorbing water and nutrients. The first shoot (called the plumule) then grows upwards, out of the soil, towards the light.

  at the beginning of the growing season too

Container maintenance

How to feed plants

Nutrient deficiencies

Caring for older plants

Once your willow is settled in and growing away well, little maintenance is needed, other than to check it is getting enough water, especially in dry summers.

You can prune shrubby willows occasionally in spring after the catkins have faded, but let young plants develop with minimal pruning. You only need to prune to maintain a balance between young stems (with the best winter colour) and older stems with catkins. On 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.

you can remove one or two of the oldest stems to encourage new growth.

You can hard prune (coppice) some of the large shrubs, to stimulate the production of colourful winter stems.

Pruning for colourful stems or large foliage

Shrubs and trees: light pruning

Coppicing

Hardwood cuttings

Shrubby willows are easy to grow from hardwood cuttings

Hardwood cuttings are taken from mid-autumn until late winter from vigorous healthy shoots of the current year's growth - this will be woody but pliable. Use for deciduous climbers, shrubs, trees (including fruit) and some evergreens such as hollies.

, between November and February – see our guide below.

With willows in particular:

• Select healthy, woody stems from the current year’s growth, about pencil thickness and 20–30cm (8–12in) long
• Insert into deep containers filled with a 50:50 mix of peat-free multi-purpose 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.

  and coarse grit
• Keep in a coldframe or cool greenhouse over winter
• Check from time to time to make sure they haven’t dried out or are sitting in soggy compost
• New shoots will appear from the buds in spring
• They should be ready to plant out in autumn, and can be pruned (coppiced) if necessary after two or three years

Cuttings: hardwood

Shrubby willows are usually trouble free if grown in a sunny position in moist but well-drained soil (some are tolerant of wet soils but not dry).

However, there are a few problems to look out for:

• willow anthracnose, scab and canker
• honey fungus
• tree rusts
• large willow bark aphids
• willow leaf beetles
• scale insects
• caterpillars and sawflies
• slugs and snails, which may damage soft, young, leafy growth
• vine weevils, which can damage roots, especially in containers

If you’re a member of the RHS, you can use our online Gardening Advice Service, via MyRHS for any questions or gardening problems.