Shrub · Oleaceae
Border Forsythia
Forsythia × intermedia
Plant it for the first burst of yellow that opens long before anything else wakes up in spring.
Full sun
Every 7–14 days
USDA 5–8
8–10 ft · 2.4–3 m
Overview
If you want a plant that announces winter is over, this is it. Early in spring the bare branches break out in bright yellow bells, weeks before the leaves show up and before most of the garden has even woken. It's in the olive family, and it grows fast into a big, arching mound, which is exactly why people have leaned on it for shrub borders and bank plantings for ages.
The nice thing? It barely asks for anything. It shrugs off clay, sand, poor ground, and city soil, it's happy in hardiness zones 5 through 8, and once its roots are down it'll ride out a dry spell just fine. There's really only one thing it won't compromise on, and that's sun. Stick it in shade and you lose the flowers, which are kind of the whole reason you'd plant it.
The one thing to know going in is size, and it's a big one. A grown shrub hits 8 to 10 feet (2.4 to 3 m) tall and spreads even wider, and those low branches root wherever they touch down, so it'll form thickets if you let it. Give it room to arch and a quick trim every year right after it blooms, and it stays good-looking instead of turning into a mess.
Care
The short version: full sun for the best flowers, pretty much any well-drained soil works, keep it evenly watered while it settles in, and prune just once a year right after the blooms fade.
Light
Give it full sun if you want the heaviest bloom. It'll still grow in partial shade, but every hour of shade costs you flowers, and a shaded plant just goes leafy and short on color.
Water
Water it regularly that first year so the roots settle in, then you can mostly leave it alone. Once it's established it handles short dry spells fine and only wants medium, even moisture, roughly a good soak every 7 to 14 days when it's dry. Just keep it out of soggy ground, since that's what brings on root rot.
Soil
When it comes to soil, forsythia really isn't fussy. It takes clay, loam, sand, even tired city dirt, and all it really wants is a spot that drains well and sits somewhere in the 6.0 to 8.0 pH range.
Temperature
It's a cold-hardy shrub, comfortable from about -20°F to 95°F (-29°C to 35°C). The plant itself shrugs off hard winters, though the flower buds can get nipped once it drops below roughly -5°F.
Humidity
Regular outdoor air is all it needs, so there's no humidity number to worry about. What actually matters is good airflow, because crowded, damp leaves are where leaf spot likes to start.
Feeding
It's not a big eater. A balanced shrub fertilizer or a bit of compost in early spring is plenty, and going overboard just gets you more leaves and fewer flowers.
Pruning
Prune once a year, right after the flowers fade, and you're set. Thin out the oldest stems at the base, and every 3 to 4 years cut the whole thing back near the ground to freshen it up. Wait past mid-July and you'll be cutting off next spring's buds, since the flowers form on old wood.
Repotting
It's a landscape shrub, so it almost never lives in a pot. But if you do grow one in a container, only repot when the roots start circling and matting, water runs straight through, or new growth stalls.
Size & spacing
Plan for a big one. A grown forsythia stands 8 to 10 feet (2.4 to 3 m) tall and spreads even wider, around 10 to 12 feet (3 to 3.7 m), so give it the room to arch out without crowding whatever's next to it.
When to plant
Forsythia pretty much runs on the early-spring calendar. Pop new plants in the ground in spring or fall once the soil's workable and hard frost is done, enjoy the yellow bells opening in March and April before the leaves, then do your one yearly trim the moment the flowers fade.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Spring or fall, after the ground is workable and the threat of hard frost has passed.
- Harvest: Early spring (March to April), before the leaves emerge.
Hardiness
USDA hardiness zones: 5–8
Temperature: down to -29°C
Troubleshooting
Forsythia is tough, so it doesn't give you much trouble, and when it does it usually comes back to the wrong spot or the wrong pruning date. The list below covers what actually tends to go wrong. Find the match, then fix the cause instead of chasing the symptom.
It's wilting and the roots look rotten
If your forsythia is wilting and going downhill in wet, heavy soil, the prime suspect is Phytophthora root rot, which leaves the roots dark and mushy. If instead you find little knots or swellings on the roots, that's root-knot nematode, and either way, steady overwatering in packed soil just makes it worse. Dig up a struggling plant so you can actually see the roots, then sort out the drainage and ease off the watering. If one shrub is too far gone, it's better to pull it and start over on a raised, well-drained spot.
Fix:
- Improve drainage and reduce watering
- Remove severely affected plants
- Replant in a raised, well-drained site
Spring came but the flowers didn't
Wondering where the flowers went? Nine times out of ten it comes down to pruning at the wrong time. The buds sit on old wood, so anything you cut after mid-July takes next spring's show right along with it. Shade does its part too, thinning things out, and a really hard winter can knock out the buds once it drops below about -5°F (-21°C). So prune as soon as the flowers fade, give it all the sun you can, and where winters are brutal, go with a tough cultivar.
Fix:
- Prune only immediately after flowering, never in summer or late winter
- Move or limb up nearby plants to give the shrub full sun
- In cold regions choose hardier cultivars such as Northern Sun or Meadowlark
Spotty leaves and stems that are dying back
Spots showing up on the leaves? That's usually fungal leaf spot, and when the tips go sunken and dead it's more likely stem dieback or canker, which a thirsty, drought-stressed plant brings on. Take a look at the base while you're there, because rough woody lumps mean crown gall. The fix is straightforward: cut the dead and cankered wood back to healthy tissue, wipe the pruners between cuts so you don't spread anything, and thin the shrub out so air can get through. Watering down low instead of overhead keeps the leaves dry, and dry leaves give those spores nowhere to go.
Fix:
- Remove and discard affected leaves and prune out dead or cankered wood to healthy tissue
- Disinfect pruners between cuts
- Improve air circulation by thinning the shrub
- Water at the base to keep foliage dry
Toxicity
Good news if you've got pets or little ones running around: forsythia is non-toxic, full stop. The ASPCA lists it as safe for dogs, cats, and horses, and there aren't any poisonous compounds in it. The flowers taste bitter too, so most animals won't bother making a habit of it.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Cats are fine around it. If one tastes a leaf or flower, nothing bad happens, and honestly the bitter flavor usually sends them off before they get more than a bite.
Dogs None
Dogs can brush against it or have a chew and they'll be okay. About the worst that a big mouthful of any plant might do is cause a quick, mild tummy ache that passes by itself.
Horses None
Horses are covered too, since it's listed as non-toxic to them. A bit of grazing on the leaves won't poison them.
Rabbits Safe
There's nothing in it that can poison a rabbit, so a stem they can reach isn't a problem. And those bitter flowers? They usually keep a rabbit from chewing much anyway.
Livestock Safe
Cattle, goats, and sheep can hang out along a pasture edge with forsythia and there's no poisoning to worry about.
Birds Safe
Birds that land in it or peck at it have nothing to fear, because the leaves, flowers, and stems aren't toxic to them.
People Safe
Go ahead and plant it where kids play, and prune it bare-handed if you want. None of it is poisonous, though washing your hands after any garden work is just a good habit.
No special handling required; the flowers are bitter, which discourages nibbling. Wash hands after pruning as a general practice.
Varieties
Most forsythia you'll find at the garden center is this hybrid, but the named cultivars aren't all the same, they vary in size, hardiness, and just how much they flower. A few are worth knowing by name.
Lynwood (Lynwood Gold)
It's the upright one that's become the go-to standard, with bright yellow flowers spaced evenly the whole way up the stems.
Spectabilis
This is the real show-off, piling on so much deep yellow bloom it just about hides the branches.
Beatrix Farrand
It's an extra-eager grower with big flowers in a deep canary yellow.
Northern Sun
If your winters are tough, this is the one, hardy to about zone 4, getting to roughly 10 feet tall and still keeping its buds through the cold.
Gold Tide
It's a low, spreading dwarf that works nicely as groundcover or for holding a bank or slope in place.
Companions
Forsythia pairs well with early bloomers that pick up where its yellow leaves off, and poorly with anything trying to grow in the shade beneath its dense canopy.
Plant near
Daffodils: Yellow daffodils bloom at the same time and echo the forsythia's early-spring color at ground level.
Lilac: Lilac flowers shortly after forsythia, extending the shrub-border bloom season; both share full-sun, well-drained conditions.
Keep apart
Turfgrass directly beneath the canopy: The dense arching canopy and surface roots shade and compete with lawn grass, which struggles under the shrub.
How to propagate
Want more? You're in luck, because few shrubs are easier to copy. Forsythia roots from cuttings, or it just layers itself wherever a branch leans down to the soil, so one plant turns into many in no time.
Stem cuttingsEasy
Late spring to summer · 4 to 8 weeks to root
Honestly, forsythia roots from cuttings without much fuss at all. Take softwood cuttings in late spring or early summer, or grab semi-hardwood ones a bit later in the year, and most of them will root within 4 to 8 weeks.
LayeringEasy
Spring through summer · One growing season to root
Here's the easy one: the arching branches root all by themselves wherever they touch the ground. Just pin a low branch down anytime from spring through summer, let it have a full growing season to root, then snip it off the parent and move your new plant where you want it.
Myths
Forsythia should be cut back hard in late winter to make it bloom better.
It seems logical, but a hard late-winter cut actually takes off the flower buds, which formed back on last year's wood. Cut heavily at the wrong time and you'll thin out the spring show or lose it altogether. Just prune right after it flowers and next year's buds stay put.
Forsythia berries and flowers are poisonous to pets and children.
You can let that one go. The ASPCA has Forsythia, also called Golden Bells, down as non-toxic to dogs, cats, and horses, and it's considered safe around kids too. There aren't any toxic principles in the plant, and the bitter flowers keep animals from browsing much on their own.