Forsythia Forsythia x intermedia
Forsythia (Forsythia x intermedia) is a deciduous perennial shrub in the Oleaceae family. It grows 1.5–3 m (4.9–10 ft) tall and 1.5–3 m (4.9–10 ft) wide, wants full sun and low water, and is hardy to about -30 °C (-22 °F). Space plants about 2 m (6.6 ft) apart.
Plan Forsythia in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Forsythia at a glance
| Type | Perennial shrub, deciduous |
|---|---|
| Family | Oleaceae |
| Mature height | 1.5–3 m (4.9–10 ft) |
| Mature spread | 1.5–3 m (4.9–10 ft) |
| Spacing | 2 m (6.6 ft) centre to centre |
| Sun | Full sun, at least 5 h of direct sun a day |
| Water | Low; drought tolerance moderate, waterlogging tolerance none |
| Cold hardiness | About -30 °C (-22 °F) once established (roughly USDA zone 4) |
| Heat stress | Likely above about 32 °C (90 °F) |
| Flowering | from about March for 2–4 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Low |
| Pollinator value | Moderate |
| Edible | Not grown as food |
| Common in gardens of | 🇬🇧 United Kingdom, 🇩🇪 Germany, 🇺🇸 United States, 🇯🇵 Japan, 🇨🇳 China, 🇰🇷 South Korea |
Is Forsythia toxic?
- People: not known to be toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
Forsythia is not known to be toxic to people or pets.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Forsythia
No well-documented helpful pairing. Group it with plants that like full sun and low water.
Questions about Forsythia
- How far apart should I plant Forsythia?
- About 2 m (6.6 ft) apart, centre to centre. A mature plant spreads 1.5–3 m (4.9–10 ft).
- Does Forsythia need full sun?
- Full sun: at least 5 hours of direct sun a day.
- How much water does Forsythia need?
- Low water. Drought tolerance is moderate and waterlogging tolerance none.
- How cold-hardy is Forsythia?
- It tolerates about -30 °C (-22 °F) once established, roughly USDA zone 4.
- When does Forsythia flower?
- From about March for 2–4 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Forsythia poisonous to cats and dogs?
- For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. Forsythia is not known to be toxic to people or pets.
- What grows well with Forsythia?
- There is no well-documented companion pairing for Forsythia. Group it with plants that like the same sun (full sun) and water (low).
Sources and evidence
Evidence grade C (C: plausible, mixed evidence).
- ASPCA Toxic and Non-Toxic Plant List, ASPCA
- FAO Irrigation and Drainage Paper 56 — Crop Evapotranspiration, FAO
- RHS Plant Finder, Royal Horticultural Society
- University extension gardening guides (general), Various land-grant university extensions
Notes and assumptions
- Typical garden-cultivar values; varieties differ.
- Flowers on bare wood in early spring.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Common lilac Syringa vulgaris
- Common privet Ligustrum vulgare
- Common jasmine Jasminum officinale
- Olive Olea europaea
- Sweet osmanthus Osmanthus fragrans
- Arabian jasmine Jasminum sambac
- Early lilac (Chinese lilac) Syringa oblata
- Night jasmine (parijat) Nyctanthes arbor-tristis