Shrub
How to grow forsythia
Forsythia × intermedia
Forsythia grows in any UK soil that is not waterlogged, in sun or light shade, and is fully hardy. Plant bare-root or pot-grown shrubs between October and March. The one thing that decides whether it flowers is when you prune: it blooms in March and April on wood made the previous summer, so cut it back as soon as the flowers fade and leave it alone for the rest of the year.
- Hardiness
- Fully hardy
- Position
- Full sun to light shade
- Soil
- Most soils; free-draining
- Ideal pH
- 6.0 to 7.5
- Water
- Low
- Feeding
- Light feeder
Sowing and planting forsythia
WhenPlant Oct to Mar; flowers Mar to Apr; prune straight after
Starting off
Plant bare-root Nov to Mar or pot-grown Oct to Mar into any soil but a bog. Propagate by 20 to 30 cm hardwood cuttings in Nov in a slit trench outdoors, rooting by the following autumn with near-100 per cent success, or by softwood cuttings in Jun. Arching stems that touch the ground layer themselves; lift and move the rooted tip in Oct.
Spacing and planting
Final size 2 to 3 m tall by 2 to 3 m wide, or 1.5 to 2 m as a clipped hedge; plant 45 to 60 cm apart for a hedge, 2.5 m as specimens, in a hole twice the pot width at pot depth. Only the dwarf 'Mikador' or 'Minigold' suits a 40 cm pot; the species is not a container plant.
Varieties worth growing
- F. × intermedia 'Lynwood Variety'
- The standard by which the others are judged: large, rich yellow flowers all along upright stems to 3 m.
- F. × intermedia 'Week End'
- More compact at about 2 m and flowers heavily from a young age; the better choice for a small garden or a hedge.
- F. × intermedia 'Spectabilis'
- Vigorous, very free-flowering old variety that makes a dense informal hedge quickly.
- 'Minigold'
- Dwarf, around 1 m, for the front of a border or a 40 cm pot where the full-size shrub would be too much.
- F. suspensa
- Long, lax stems that can be tied to wires on a north or east wall, where it flowers well with little sun.
Forsythia month by month
Timings are for central England. Allow two weeks later in the north and on cold, heavy soil.
- January
Plant in mild spells. Cut a few budded stems and bring them indoors to flower in a vase.
- February
Plant bare-root and pot-grown shrubs. Do not prune.
- March
Flowering starts. Last bare-root planting.
- April
Prune as soon as the flowers fade: flowered stems back to a strong low shoot, and one in four old stems out at the base. Clip hedges. Feed if needed.
- May
Finish any pruning in the first week. Water plants set out this year.
- June
Softwood cuttings. No more pruning.
- July
Nothing to do. The long shoots growing now carry next spring's flowers, so leave them.
- August
Nothing to do.
- September
Nothing to do.
- October
Planting season opens. Lift and move stem tips that have rooted where they touched the ground.
- November
Hardwood cuttings, 20 to 30 cm, in a slit trench outdoors. Plant bare-root shrubs.
- December
Plant in mild spells. Nothing else to do.
Feeding forsythia
A light feeder that grows vigorously without help. On reasonable soil a mulch is plenty; feed only after pruning on poor soil, and properly after a hard renovation.
Low, tough and easy; a light spring feed.
Feeding plan
Planting
5 g per litre of root ball, onto the roots: 15 g for a 3 litre pot. For a bare-root shrub, dust about 10 g over the damp roots.
April, after pruning, on poor or sandy soil
50 g/m², half the label rate, once: about 150 g under a shrub 2 m across (roughly 3 m²). On good soil, none.
April, after cutting an old shrub down to 30 cm
100 g/m² once (about 300 g for a 2 m shrub), followed by a 5 cm compost mulch.
April, hedges
50 g/m² on a strip 1 m wide after clipping: 50 g per metre of hedge.
Dwarf varieties in pots
5 g per litre at potting (125 g for a 40 cm pot of about 25 litres), then 2 g per litre (50 g) on the surface each April.
Signs to watch
Vigorous leafy growth with few flowers
Excess nitrogen, or pruning at the wrong time
No feed, prune only in Apr straight after flowering
Yellowing between the veins on older leaves on thin chalk
Magnesium short
Epsom salts drench at 20 g per litre in May
Pests, diseases and problems
Rough, knobbly woody swellings along the stems
Forsythia gall; the cause is not fully understood
Harmless in small numbers. Cut galled stems out at the base when you prune in April and bin them.
Flower buds stripped in late winter, leaving stems that flower only at the tips
Bullfinches and sparrows eating the buds
Usually worth tolerating. On a small or wall-trained plant, drape netting over it from January until the buds open.
Young leaves peppered with small ragged holes
Capsid bugs feeding on the shoot tips in May and June
Cosmetic and over by midsummer; no treatment needed.
A stem that is flat and ribbon-like, sometimes curled at the tip
Fasciation, a growth abnormality that forsythia is prone to
Harmless and not infectious. Cut the odd stem out at its base if you dislike it.
Branches die back and the whole shrub fails, with white fungal sheets under the bark at soil level
Honey fungus
Remove the shrub with as much root as you can and do not replant with another susceptible shrub in the same spot.
Pruning
Pruning and care
Flowers on the previous year's wood, so prune immediately after flowering in Apr: cut flowered stems back to a strong low shoot and remove 1 in 4 of the oldest stems at the base to keep the bush open. Pruning in summer or winter removes next spring's flowers. Neglected plants renovate well, cut to 30 cm in Apr with a feed and mulch, flowering again 2 years later. Hedges are clipped once, straight
Good to knowPrune straight after the early-spring flowers (it blooms on old wood).
Growing forsythia in pots
The full-size forsythias are too vigorous for a pot and soon become starved and bare at the base. A dwarf such as 'Minigold' or 'Mikador' will do in a 40 cm pot of loam-based compost for several years. Water regularly from April to September, prune after flowering as for plants in the ground, and replace the top 5 cm of compost each spring.
Forsythia: common questions
When should I prune forsythia?
Prune in April, immediately after flowering and no later than early May. Cut flowered stems back to a strong shoot lower down and remove one in four of the oldest stems at ground level. Anything cut from June onwards takes next spring's flowers with it.
Why is my forsythia not flowering?
Nearly always because it was pruned or clipped in summer, autumn or winter, which removes the wood that carries the buds. Other causes are heavy shade, nitrogen from nearby lawn feed, and birds stripping the buds in late winter. Prune only in April and it should flower the following spring.
Does forsythia make a good hedge?
Yes, it makes a fast, dense informal hedge 1.5 to 2 m high, planted 45 to 60 cm apart, though it is bare in winter. Clip it once a year straight after flowering. A hedge sheared repeatedly through summer stays tidy but hardly flowers.
Sources
Growing information on this page was checked against these references in November 2026. Feeding rates are Dr Forest label rates.