How big does Border forsythia grow?

About 2.5 m × 2.5 m after ten years (height × width). Its ultimate size is 1.8–3 m × 2.4–3.6 m.

What soil does Border forsythia grow in?

It tolerates these soils: average garden soil, clay, sandy, calcareous, acidic.

Is Border forsythia hardy?

Hardy down to -29 °C (USDA zone 4, RHS H7). It gets through winter in every part of the country.

Is Border forsythia toxic to dogs?

No. Reliable sources list it as non-toxic to dogs.

Is Border forsythia toxic to cats?

No. Reliable sources list it as non-toxic to cats.

Is Border forsythia toxic to children?

No. Reliable sources list it as non-toxic to children.

How far from the house should Border forsythia be planted?

Plant it at least 2 m from buildings. Keep it at least 0.5 m from paving.

How far apart should Border forsythia be planted?

Planted on its own, it needs 1.5 m between plants. For a hedge, allow 2.5 plants per metre.

When does Border forsythia flower?

Flowering: March–April, yellow.

How much water does Border forsythia need?

Water need: medium. Drought tolerance: medium.

How much does Border forsythia cost?

It sells for roughly €4.90 to €13 in local shops, depending on size.

Border forsythia

Forsythia × intermedia

Border forsythia (Forsythia × intermedia) is a shrub that reaches 2.5 m × 2.5 m after ten years. Light: full sun, part shade. Hardy down to -29 °C. Drought tolerance: medium. Non-toxic to dogs, cats and children. Sold in local shops from about €4.90.

Illustration of Border forsythia — An illustration of the typical shape of the mature plant, not a photo.

What it's good for, and what it isn't

A fast-growing shrub with arching branches that are lined with golden yellow flowers in early spring, before the leaves appear. It is undemanding, grows in almost any soil and puts up with city air and short dry spells, so it works well as a flowering hedge, a screen or in a shrub group. Prune it straight after flowering, because next year's buds form over the summer; left unpruned it soon turns into a tangled shrub that is bare at the base.

Watch out for

The flower buds are killed below roughly -20 °C, so in the colder corners of Central Europe flowering can be thin after a hard winter or a late freeze, although the shrub itself is unharmed. Branches that touch the ground take root and the base can sucker, so it sprawls without regular thinning. Leaf spot, crown gall and dieback occur but are seldom serious.

Key facts

Light: Full sun, Part shade
Water need: Medium
Care: Medium
Size after 10 years: 2.5 m × 2.5 m
Hardiness: down to -29 °C
Foliage: Deciduous
Flowering: J F M A M J J A S O N D March–April, yellow

Group	Shrub
Light	Full sun, Part shade
Size after 10 years	2.5 m × 2.5 m
Ultimate size	1.8–3 m × 2.4–3.6 m
Hardiness	down to -29 °C (USDA 4, RHS H7)
Soil	Average garden soil, Clay, Sandy, Calcareous, Acidic
Foliage	Deciduous
Flowering	March–April, yellow
Water need	Medium
Drought tolerance	Medium
Maintenance	Medium
Root aggressiveness	Low
Suckering	yes
Spreading	Medium
Distance from buildings	at least 2 m
Distance from paving	at least 0.5 m
Litter	not typical
Planting distance	150 cm
For dogs	Non-toxic
For cats	Non-toxic
For children	Non-toxic
Typical price	from about €4.90

Toxicity data is for information only. If your pet or child has eaten a plant, contact a vet or a doctor.

Sizes and prices available

The same plant is sold as a small pot and as a specimen several metres tall, and the price follows. Prices are rounded and for guidance only.

Size	Typical price
20+ cm	approx. €7
30+ cm	approx. €7
size not stated	approx. €4.90 – €13

Frequently asked questions

Data updated: October 13, 2026 · How our data is made

Appears in these lists

Shrubs for part shade Plants that are non-toxic to dogs Plants that are non-toxic to cats Plants that are non-toxic to children Hedge plants Plants for screening Flowering shrubs

Guide on the topic

Fast-growing hedges: how much each grows in a year The fastest hedge plant is the Leyland cypress, growing about 90 cm a year, followed by cherry laurel 'Novita', firethorn and western red cedar at about 50 cm a year, then privet at 40 cm. How long a 180 cm hedge takes to screen depends more on the size of plant you buy: several years from small plants, one or two summers from large ones, but at many times the price per metre. The tables use the current shop prices in your country.

Looks good next to it

Heartleaf bergenia

Bergenia cordifolia

Blue holly

Ilex × meserveae

Rose rock cress

Arabis blepharophylla