How to grow forsythia

Choosing a forsythia

You might think that forsythias are all very similar, covered as they are in masses of golden-yellow flowers in early and mid-spring. There are some subtle differences, however, and here are some things to consider before buying:

• Plant height – forsythias are usually tall, vigorous shrubs reaching about 2m (6⅔ft) in height if left unpruned. If space is tight, there are several smaller cultivars, including F. × intermedia Minigold (‘Flojor’) at 60cm (2ft) tall and F. ‘Fiesta’ at 1–1.2m (3⅓–4ft) tall and with variegated leaves. Both of these could also be grown in containers

• Style of growth – for a forsythia hedge, choose a strong upright

  Gardeners often use the word variety when referring to a specific plant, but the correct botanical term is 'cultivar'. Whichever word you use, it means a distinctive plant or plants, given a specific cultivar name and usually bred to enhance certain characteristics, such as flower or fruit size, colour, flavour or fragrance, plant size, hardiness, disease resistance, etc. Additionally, it is worth knowing that, botanically, variety has another meaning - it refers to a naturally-occurring distinct plant that only has slight differences in its looks. For example, Malva alcea var. fastigiata differs from typical plants by having an upright habit.

  cultivar such as F. × intermedia ‘Lynwood Variety’ or F. × intermedia ‘Spectabilis’

• Flower colour and size – forsythias all have yellow flowers, but a few cultivars offer different shades of yellow or larger-than-normal flowers. Forsythia suspensa f. atrocaulis, for example, has pale lemon flowers, while F. × intermedia 'Goldrausch' has noticeably bigger flowers

To browse photos and descriptions of many forsythia cultivars, go to RHS Find a Plant. You can also search by size, planting position and RHS Award of Garden Merit, to help narrow down your choices.

How and what to buy

Single shrubs

Forsythias are widely sold in garden centres, nurseries and online by mail order. They are usually container-grown plants, in 2–3 litre pots, although larger plants may sometimes be available. When selecting a plant to buy:

• Look for a balanced shape, with evenly spaced branches

• Avoid plants showing signs of stress, damage or disease, such as broken shoots or yellowing leaves

• Check for healthy roots – there should be enough roots so that they’re visible through the holes in the base of the pot, but they shouldn’t be so congested that you can’t see any soil

For hedging

Forsythia is sometimes available as bare-root plants from online hedging suppliers during the dormant season (November to February). These are supplied without pots or soil, with the roots simply wrapped in plastic to stop them drying out. They tend to be cheaper than containerised plants, especially if you’re buying several for a hedge, although the choice of cultivars is limited.

The plants are usually about 60cm (2ft) tall and must be planted as soon as they are delivered.

Forsythia for hedging

Forsythia for hedging

These small plants settle in more rapidly than larger plants, which may struggle to get established, especially during hot summers. However, if you want to create a hedge quickly, buying semi-mature plants gives a more immediate effect.

Buying: garden centre plants

Buying: garden centre plants

Buying: mail order plants

Buying: mail order plants

Buying: trees and shrubs

Buying: trees and shrubs

RHS guide to buying healthy plants

RHS guide to buying healthy plants

When to plant

• The best time to plant container-grown forsythias is in spring or autumn. However, they can be planted at any time, as long as the soil isn’t frozen, too wet, or excessively dry in summer. If you buy a forsythia in summer, plant it as soon as possible and water it regularly to keep the soil moist but not soggy – don’t let it dry out, as this could kill the plant

• Plant bare-root forsythias in mild periods between November and February. Plant them as soon as possible after they are delivered

Where to plant

Forsythias are easy-to-grow, versatile shrubs that work well in many positions in the garden. They can add height in mixed borders, be trained against walls and grown as stand-alone specimens or hedges.

Bear in mind the following when choosing a planting site:

• Forsythias thrive in most types of soil, except waterlogged ground

• They prefer a sunny spot, but will tolerate light shade. However, forsythias in shade produce fewer flowers than those in sun

• They are very hardy, so cope well in cold locations

• Most will eventually grow to about 2m (6½ft) tall and wide, so allow enough space if you want your plant to develop its natural shape, or be prepared to prune it annually after flowering (see Pruning and Training below)

• To make a dense, formal hedge, space plants 45–60cm (18in–2ft) apart. If you’re prepared to wait for them to knit together or want a less formal look, you can space plants more widely, up to 90cm (3ft) apart

How to plant

Forsythias are easy to plant, using the standard method for planting any shrub, hedge or container. Simply follow our step-by-step guides:

Growing plants in containers

Growing plants in containers

Hedges: planting

Hedges: planting

Trees and shrubs: planting

Trees and shrubs: planting

Watering

Like most shrubs, newly planted forsythias should be watered regularly and thoroughly for the first few years, until their roots are well established. This is particularly important during dry spells in spring and summer.

Once established, forsythias are fairly drought tolerant and shouldn’t generally need additional watering. However, on very free-draining soil or during prolonged hot, dry spells, some extra water may be needed to support continued healthy growth. Look out for shrivelled leaves, which may be a sign your forsythia needs watering.

RHS video guide to watering efficiently

RHS video guide to watering efficiently

Feeding and mulching

Forsythias generally need little or no regular feeding in most types of soil.

However, to encourage strong new growth after pruning in spring, you may wish to feed. In which case, sprinkle a granular fertiliser such as Growmore around the plant, at the rate recommended on the packet.

Then add a mulch on top – a 5cm (2in) layer of organic matter, such as home-made compost or well-rotted manure. Leave a mulch-free circle immediately around the base of the plant to prevent the stems rotting.

Mulches and mulching

Mulches and mulching

Plant nutrition: feeding plants

Plant nutrition: feeding plants

Without regular pruning, forsythias tend to develop into tall, ungainly shrubs with congested growth and bare stems at the base. Flowering performance declines and any flowers are mostly borne on long, vigorous shoots at the top of the plant.

Still, pruning forsythias is quite straightforward, whether you have a free-standing shrub, a wall-trained shrub, an overgrown specimen or a hedge. Simply follow our advice below.

Pruning young forsythia plants

Allow young plants to develop naturally with minimal pruning. Just remove any dead, damaged or badly positioned shoots in late spring after flowering.

Pruning established forsythias

Prune in mid-spring, immediately after flowering – avoid pruning later in the year, as the following spring’s flowers will be reduced. Annual pruning keeps plants healthy, shapely and within bounds: 

• Cut back flowered growth to vigorous upward- and outward-facing shoots lower down

• Also remove up to one-fifth of the oldest stems from the base of the plant. This will encourage strong new shoots to sprout from the base

• Thin out any crowded shoots in the centre of the bush and remove any weak growth

• If you wish to avoid pruning, choose a dwarf cultivar such as ‘Fiesta’, which needs very little pruning

For more tips, see our guide below.

RHS guide to pruning early flowering shrubs

RHS guide to pruning early flowering shrubs

Pruning neglected forsythias

If your forsythia has grown too large, is mis-shapen or badly congested, you can give it a new lease of life by hard pruning. It’s best to carry this out during the dormant season, between autumn and early spring, but bear in mind that the plant won’t produce any flowers in the first spring after such pruning.

You can either prune the entire shrub in one year or, if you would like to keep some of the existing structure and flowers, then spread the pruning over two years.

Our guide to renovating shrubs below takes you step-by-step through this process.

RHS guide to renovating shrubs

RHS guide to renovating shrubs

Pruning forsythia hedges

These should be pruned annually, in the same way as stand-alone shrubs:

• Cut back the flowered shoots immediately after flowering, aiming to restore the outline of the hedge

• Remove a few of the oldest stems, to stimulate new replacement shoots from the base

Step-by-step RHS guide to hedge trimming

Step-by-step RHS guide to hedge trimming

Pruning wall-trained forsythias

The aim is to develop a framework of stems to cover the desired space, trained to horizontal wires or trellis attached to the wall or fence:

• Straight after flowering, reduce the length of the flowered stems to one or two buds from the branches that form the main framework

• If older framework branches flowered poorly, cut them out and select younger shoots as replacements

• Tie these new stems into the desired position, to fill any gaps or extend the area covered

Climbers and wall shrubs: pruning established plants

Climbers and wall shrubs: pruning established plants

From cuttings

Taking cuttings is an easy way to make new forsythia plants. The resulting plants will be exactly the same as the parent, which is useful if you need to fill gaps in a forsythia hedge.

There are three different types of cutting, depending on the time of year:

• Take softwood cuttings from late spring to early summer, selecting young, healthy, non-flowering shoots. Rooting takes two to four weeks. Grow them on in pots for planting out the following season

• Take semi-ripe cuttings from midsummer to early autumn, rooting these directly into small pots and overwintering in a coldframe or unheated greenhouse. Pot on young, well-rooted cuttings in spring

• Take hardwood cuttings from mid-autumn to late winter. These will be the slowest to root – simply leave them undisturbed in their pots until the following autumn

Forsythia cuttings taken by any method will root more quickly if given bottom heat in an electric propagator.

For more information on these techniques, see our handy guides below.

Cuttings: hardwood

Cuttings: hardwood

Cuttings: semi-ripe

Cuttings: semi-ripe

Cuttings: softwood

Cuttings: softwood

By layering

This is a useful technique for shrubs that have low-growing or flexible stems, such as Forsythia suspensa. It is very simple, with little ongoing maintenance required:

• In spring or autumn, find a low-growing stem that can be bent down to the ground, then pin it to the soil surface with a loop of wire

• Keep the soil moist to encourage rooting, which will usually take six months or more

• Once the new plant is firmly rooted, the connecting stem to the parent plant can be cut and the new plant moved to a new location

For more information, see our guide below.

RHS guide to layering

RHS guide to layering

From seed

This is a slower way to grow new forsythia plants, and the offspring may differ slightly from the parent plants. But it is well worth a try:

• Once the seed pods are ripe and split open, collect the seeds

• Store the seeds until autumn, then sow in a seed tray outdoors, allowing natural winter chilling to break their dormancy 

• Seedlings should appear in spring

​ 

Seed: collecting and storing

Seed: collecting and storing

Trees and shrubs from seed

Trees and shrubs from seed

Forsythias are robust, hardy and usually trouble-free shrubs. However if your forsythia isn’t thriving, check out our guides below.

Brown leaves on woody plants

Brown leaves on woody plants

Trees and shrubs: establishment problems

Trees and shrubs: establishment problems

Why has my tree or shrub died?

Why has my tree or shrub died?

Sometimes forsythias may produce odd-looking flattened, elongated shoots that look like many stems compressed together. This is known as fasciation, and although it may look strange it doesn’t affect the health of the plant.

RHS guide to fasciation

RHS guide to fasciation

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