Forsythia

Forsythia x intermedia (border forsythia) · Olive family (Oleaceae)

At a glance
Hardiness zones	5 to 8
Sun	full sun to part shade
Water	moderate
Life cycle	perennial
Frost	Hardy: takes frost
Spacing	36 to 48 inches

About Forsythia

Forsythia is a fast-growing, fountain-shaped shrub that lights up early spring with yellow bells before its leaves come out. It is a hybrid of two Chinese species; it tolerates poor soil, drought and city conditions and is easy to transplant (NC State, Clemson). Give it room: full-size plants reach 8-10 ft tall and 10-12 ft wide.

Hardy in zones 5-8; temperatures below about -5 F or a late freeze can kill the flower buds (NC State). 'Northern Sun' is hardy to zone 4 (Clemson).

When to plant

Timing is counted from your average last spring frost (and first fall frost). Sow & Tell works out the actual dates for your ZIP code.

For a hedge, space plants 3-4 ft apart (Clemson). Skip foundation beds unless you pick a compact cultivar.

Soil

Loose, well-drained soil is best, but it grows in almost any soil; wet soil invites Phytophthora root rot (Clemson, NC State).

Test the soil before planting; mature shrubs in decent soil need little or no fertilizer (Clemson).

Feeding

Spring to early summer after new growth starts, only if a soil test shows a need: slow-release complete fertilizer in a 3:1:2 ratio, or what the soil test calls for. Spread evenly from the trunk out to the drip line and water it in; a typical soil-test rate for shrubs is about 2 lb of 12-6-6 per 100 sq ft (Clemson). Follow a soil test.

Water is what new shrubs need most: daily for the first 2 weeks, every 2-3 days through week 12, then weekly until the roots spread (at least two growing seasons), using about a quarter to a third of the nursery pot's volume each time (UMN). Water weekly in long droughts to lower the risk of Botryosphaeria canker (Clemson).

Harvest

Blooms late February to March for 2-3 weeks, before the leaves. Prune right after flowering by cutting the oldest stems to the ground; pruning after mid-July removes next spring's buds. Cut branches in January-February and bring them indoors to bloom in about 10 days (Clemson, NC State).

Varieties (15)

Variety	Type	Notes
Beatrix Farrand	Border forsythia	8-10 ft; vivid golden flowers; strong flower size, vigor and habit.
Karl Sax	Border forsythia	Up to 6 ft, bushy; blooms about 2 weeks later than others.
Show Off ('Mindor')	Border forsythia	5-6 ft; heavy bloom on stems good for cutting.
Spectabilis	Border forsythia	About 10 ft tall and wide; bright yellow; the standard new cultivars are compared to.
Spring Glory	Border forsythia	Strong grower to 10 ft; deep yellow flowers.
Lynwood (Lynwood Gold)	Border forsythia (F. x intermedia)	Upright, 8-10 ft tall and 6-8 ft wide; heavy bloom.
Gold Tide	Dwarf	24-30 in tall, 4 ft wide; lemon-yellow flowers.
Golden Peep	Dwarf	18-30 in tall, 36 in wide.
Goldilocks	Dwarf	24-36 in tall and wide.
Happy Centennial	Dwarf	24-30 in tall, 3-5 ft wide; can serve as a groundcover.
Show Off Starlet	Dwarf	2-3 ft tall, 3-4 ft wide; deep yellow; maroon fall color.
Arnold Giant	Hybrid	About 5 ft, upright, with larger, darker leaves.
Northern Gold	Hybrid	6-8 ft tall, 5-7 ft wide; golden flowers.
Sunrise	Hybrid	Mounding, about 5 ft; maroon fall color.
Northern Sun	Hybrid (F. ovata x F. europaea)	About 10 ft tall and 9 ft wide; very cold hardy.

Pests to watch for

Twospotted spider mite, Aphids, Four-lined plant bug, Root-knot nematodes

Diseases and problems

Phytophthora root rot, Botryosphaeria canker, Phomopsis gall, Leaf spot, Crown gall, Winter injury

In the kitchen

Safety: No toxicity is listed in the extension sources we used; NC State tags forsythia as non-toxic to cats, dogs and horses.

Pets: Not on the ASPCA toxic plant lists; NC State tags it non-toxic to cats, dogs and horses.

Sources

Photo: Photo: AnRo0002 / Wikimedia Commons, CC0 (CC0). Photo resized for the web.

Planting dates and advice are general guidance; check with your local Cooperative Extension office for your area.