Shrub
How to grow spiraea
Spiraea japonica / S. 'Arguta'
Plant spiraea between October and March in full sun and fertile soil that drains. It is fully hardy and easy; the one thing to get right is which kind you have. Spring-flowering spiraeas such as 'Arguta' bloom on last year's wood and are pruned straight after flowering, while summer-flowering Spiraea japonica blooms on new growth and is cut back hard in February or March.
- Hardiness
- Fully hardy
- Position
- Full sun
- Soil
- Fertile, free-draining
- Ideal pH
- 6.0 to 7.5
- Water
- Low to moderate
- Feeding
- Light feeder
Sowing and planting spiraea
WhenPlant Oct to Mar; flowers Apr to May (spring types) or Jun to Aug (summer types)
Starting off
Plant bare-root Nov to Mar or pot-grown Oct to Mar; S. japonica is often sold as cheap hedging and suckers to form clumps. Propagate by 10 cm softwood cuttings in Jun at 18°C under a bag, rooting in 3 to 4 weeks, or 20 cm hardwood cuttings in Nov; S. japonica also divides easily in Mar.
Spacing and planting
S. japonica 'Goldflame' and 'Anthony Waterer' reach 75 to 100 cm by 1 to 1.5 m; S. 'Arguta' 2 to 2.5 m by 2 m; S. nipponica 'Snowmound' 1.5 m by 1.5 m. Plant summer types 75 cm apart, spring types 1.5 to 2 m, in a hole twice the pot width. Dwarf S. japonica 'Little Princess' or 'Nana' is fine in a 35 cm pot.
Varieties worth growing
- S. 'Arguta'
- Bridal wreath: arching 2 m stems covered along their length in white flowers in April and May. The classic spring spiraea.
- S. nipponica 'Snowmound'
- A dense 1.5 m mound smothered in white in late May and June, after 'Arguta' has finished. Tidier, and good as an informal hedge.
- S. japonica 'Goldflame'
- Summer-flowering. Young leaves open orange-bronze, turn yellow then green, with deep pink flower heads in June and July.
- S. japonica 'Anthony Waterer'
- Summer-flowering. Flat crimson-pink heads from June to August on a 1 m bush; the old reliable for the middle of a border.
- S. japonica 'Little Princess'
- A low 50 to 60 cm dome with pale pink flowers in midsummer. The one for edging, ground cover and pots.
Spiraea month by month
Timings are for central England. Allow two weeks later in the north and on cold, heavy soil.
- January
Plant bare-root or pot-grown in open weather.
- February
Late in the month cut summer-flowering S. japonica to 10 to 15 cm. Do not touch spring-flowering kinds.
- March
Finish pruning summer types. Light feed and mulch for all. Divide S. japonica clumps. Last month for bare-root planting.
- April
'Arguta' flowers. Water spring-planted shrubs in dry spells.
- May
Spring types in flower. As 'Arguta' finishes, cut flowered shoots back to strong new growth.
- June
Prune 'Snowmound' after flowering and take out 1 in 4 old stems. S. japonica begins to flower. Softwood cuttings.
- July
Summer types in flower. Shear off faded heads for a second flush.
- August
Water in drought, golden-leaved kinds first. Second flush on S. japonica.
- September
Nothing to do. Do not prune.
- October
Planting season begins. Autumn colour on 'Goldflame'.
- November
Plant bare-root. Take hardwood cuttings.
- December
Plant in open weather. Otherwise nothing to do.
Feeding spiraea
A light feeder. One small balanced feed in March with a mulch is enough, and on fertile soil the mulch alone will do. Too much nitrogen turns golden-leaved kinds green and gives leaf instead of flower.
Low, easy; a light spring feed.
Feeding plan
October to March, at planting
5 g per litre of root ball, dusted onto the roots or the sides of the hole so it touches them: 15 g for a 3 litre pot. For bare-root hedging plants, dust the damp roots before planting. Once.
March, after pruning summer types
50 g/m², half the label rate of 100 g/m²: a handful round each plant, watered in. Once a year. Skip it for golden cultivars on good soil.
March
Garden compost
A 5 cm mulch over the root area after feeding, kept clear of the stems.
March, pots
2 g per litre of compost, the bottom of the label range, on the surface and watered in: about 40 g for a 35 cm pot holding roughly 20 litres. Once.
Signs to watch
Golden-leaved 'Goldflame' and 'Goldmound' turning plain green
Shade or too much nitrogen
Full sun, no feeding, hard prune in Mar
Older leaves yellowing between the veins on light soil
Magnesium short
Epsom salts drench at 20 g per litre in Jun
Scorched white patches on golden types in Jul
Sun scorch after drought, not a deficiency
Water in dry spells and give light shade at midday
Pests, diseases and problems
A spring-flowering spiraea with healthy growth and almost no flowers
Pruned in autumn, winter or early spring, which removed the wood that carried the flower buds
Prune 'Arguta', 'Snowmound' and S. thunbergii only in the weeks straight after flowering. Flowers return the following spring.
White powdery coating on leaves and shoot tips in summer
Powdery mildew, on plants that are dry at the root and crowded with old stems
Water thoroughly in dry spells, mulch in spring, and remove a quarter of the oldest stems at pruning time to open the bush.
Curled, sticky young leaves at the shoot tips in May and June
Aphids
Squash by hand or knock off with a jet of water. Ladybirds and hoverflies usually clear them within a few weeks.
A dense thicket of thin twigs with dead wood in the middle and few flowers
Years without pruning; the old stems have stopped producing strong flowering shoots
Renovate: cut every stem to within 10 to 15 cm of the ground, summer types in February or March, spring types after flowering. Mulch and water, and thin the regrowth the next year.
Plain green shoots on a golden cultivar, or pink and white flowers on one bush
Reversion; 'Goldflame' throws green shoots, and some S. japonica forms throw odd-coloured heads
Cut all-green shoots out at their base as soon as they appear, since they are stronger and take over. Mixed flower colour is harmless.
Pruning
Pruning and care
Two pruning groups. Summer-flowering S. japonica and S. × bumalda flower on new wood: cut all stems back to 10 to 15 cm from the ground in Feb to Mar, and deadhead in Jul for a second flush. Spring-flowering S. 'Arguta', S. nipponica and S. thunbergii flower on last year's wood: straight after flowering in May to Jun cut flowered shoots back to strong new growth and remove 1 in 4 old stems at the base. Bot
Good to knowPrune by type, spring-flowering after bloom, summer types in early spring.
Growing spiraea in pots
Only the dwarf summer-flowering kinds suit a pot: 'Little Princess', 'Nana' and the smaller golden cultivars. Use a 35 cm or larger pot of loam-based compost in full sun, or in light afternoon shade for golden foliage, which scorches if the pot dries out. Water whenever the surface is dry from April to September. Cut back to 10 to 15 cm in late February, feed once in March, and replace the top few centimetres of compost at the same time. Repot or divide every three years. The tall arching spring spiraeas need the open ground.
Spiraea: common questions
When should I prune spiraea?
It depends on when it flowers. Summer-flowering Spiraea japonica, including 'Goldflame', 'Anthony Waterer' and 'Little Princess', is cut back to 10 to 15 cm in February or March. Spring-flowering kinds such as 'Arguta' and 'Snowmound' are pruned straight after flowering in May or June, by cutting flowered shoots back to strong new growth and removing a quarter of the oldest stems.
Can I cut spiraea back to the ground?
Yes, spiraea regrows readily from the base. Summer-flowering kinds can be cut almost to the ground every February or March and will flower the same year. A neglected spring-flowering spiraea can be cut down after flowering, but expect it to miss a year of bloom while it rebuilds.
Why is my spiraea not flowering?
Pruning at the wrong time is the most common cause, particularly a winter tidy of a spring-flowering kind. Shade is the next: spiraea needs sun for at least half the day. Heavy feeding with nitrogen also pushes leaf at the expense of flowers.
Sources
Growing information on this page was checked against these references in November 2026. Feeding rates are Dr Forest label rates.