Tree · Malvaceae
American Basswood
Tilia americana
A big, easygoing shade tree loaded with fragrant summer flowers the bees can't get enough of.
Full sun
Every 7–14 days
USDA 3–8
60–80 ft · 18.3–24.4 m
Overview
American basswood, or just linden to most folks, is a tall native shade tree, and there's a reason people call it the bee tree. Come late spring and early summer, it covers itself in small, pale-yellow flowers you can smell on the breeze, and the pollinators are on it from sunup to sundown. Give it time and it'll reach a whopping 60 to 80 feet (18 to 24 m) with a wide, rounded crown.
This is a tree for the long haul, and an easygoing one at that. It laughs off cold winters, it's happy in full sun or part shade, and it's not picky about soil as long as the water drains away. Those big heart-shaped leaves throw down some serious shade, and that soft, light wood? That's what gave basswood its name and made it a longtime favorite with carvers.
Plant it somewhere it can spread out and you won't have to babysit it. The one thing to keep in mind is that aphids love it and drip sticky honeydew all summer, so maybe think twice before you park a car or set a patio right under the canopy.
Care
The short version: full sun to part shade in moist, well-drained soil, with steady water while it's young and not much else once it's settled in.
Light
Linden's happiest in full sun, though it'll take partial shade just fine. More sun gives you a fuller crown and more flowers, while a shadier spot still gets you a healthy tree, just a bit looser.
Water
Keep a young tree evenly moist and water every 7 to 14 days when things get dry. Once it's established it can handle a bit of drought, but it's always happier with steady moisture, so don't let it bake for weeks on end.
Soil
It's not fussy and takes clay, loam, or sand, as long as the ground is medium-moisture and well-drained. Any pH from 5.5 to 8.0 works for it, and that covers just about any garden soil you're likely to have.
Temperature
This one's tough on cold, comfortable anywhere from -40°F to 100°F (-40°C to 38°C). It handles brutal winters and hot summers alike, which is exactly why it does so well across so much of the country.
Humidity
You never have to worry about humidity with a linden outdoors, so there's no number to chase. Air circulation matters more, since still, damp air around the canopy is what brings on the leaf spots and mites.
Feeding
An established tree in decent soil hardly ever needs feeding. If it's growing weakly, work a balanced slow-release tree fertilizer in early spring, but go easy, because too much nitrogen just feeds the aphids.
Pruning
Prune in late winter to early spring to set up one strong central leader and clear out any dead, damaged, or crossing branches. It also throws up basal suckers and sprouts, so just pull those off whenever they show up.
Repotting
Linden's a landscape tree, not a container plant, so once it's in the ground, repotting doesn't really come up. If a nursery tree's got roots circling the pot or poking out the drainage holes, get it planted out sooner rather than later.
Size & spacing
Give a linden plenty of room, because it climbs to 60 to 80 feet (18 to 24 m) tall and spreads 30 to 60 feet (9 to 18 m) across. Keep it well clear of buildings, walls, and overhead lines so that wide crown has room to fill out.
When to plant
Since linden is a tree, there's no yearly sowing season to keep track of, which is nice. Just set young trees out in spring or fall, once the hard frosts are done, and the fragrant flowers show up on their own from late spring into midsummer.
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 threat of hard frost has passed
- Harvest: Fragrant pale-yellow flowers in late spring to early summer (May to July)
Hardiness
USDA hardiness zones: 3–8
Temperature: down to -40°C
Troubleshooting
A healthy linden pretty much runs itself, and most of what you'll notice is just cosmetic. Match the signs below before you grab any treatment, because a big tree usually shrugs off the pests that would stress out a smaller plant.
Wilting limbs, sawdust, and little round holes down low
The linden borer tunnels through the wood down at the lower trunk and limbs, and you'll notice round exit holes and a sawdust-like frass where it's been. Cut out any limb it's gotten into and destroy it. Borers pick on stressed trees first, so keep yours watered and keep the mower and trimmer away from the bark, and if the trunk itself is hit, that's a job for an arborist.
Fix:
- Prune out and destroy borer-infested limbs
- Keep the tree vigorous, as borers preferentially attack stressed trees
- Consult an extension office or arborist for severe trunk infestations
Sticky, shiny leaves and a black film creeping in below
So what's that shine? It's aphid honeydew, and the black that follows is just a harmless sooty mold living on the sugar. When aphids pile up, and scale insects sometimes join in, all that sweet stuff drips onto whatever's underneath. Hit the bugs with a hard spray of water, let lady beetles and lacewings mop up the rest, and the film disappears once the dripping stops.
Fix:
- Hose aphids off with a strong jet of water
- Encourage beneficial predators such as lady beetles and lacewings
- Apply insecticidal soap or horticultural oil to accessible foliage for severe infestations
- Sooty mold disappears on its own once the honeydew source is controlled
Summer leaves eaten down to lacy skeletons
Those lacy leaves? That's Japanese beetles eating everything but the veins, and they'll do it from June to August. If the tree's still young, head out early in the morning and knock the shiny green beetles into soapy water. A big, established linden really doesn't care, since it just grows new leaves, so don't bother with pheromone traps, which only invite more beetles over.
Fix:
- Hand-pick or knock beetles into soapy water in the early morning on smaller trees
- Tolerate damage on large established trees, which recover
- Avoid Japanese beetle pheromone traps, which attract more beetles
Leaves that look stippled, spotted, or a bit browned
Leaves looking a little rough? A few things could be behind it. Lace bugs, basswood thrips, or spider mites stipple the foliage and drop dark fecal specks on the undersides, and fungal leaf spots turn up as clear lesions when the weather's wet. Rake up the fallen leaves to knock down the spores, hose the canopy during dry spells to deal with mites, and other than that? Just let it be, since it's mostly cosmetic.
Fix:
- Rake and dispose of fallen leaves to reduce fungal spores
- Hose down foliage to dislodge mites in dry spells
- Most leaf spot is cosmetic and needs no treatment
Toxicity
Good news if you've got pets: linden is totally safe. The ASPCA lists it as non-toxic to cats, dogs, and horses, and there's nothing poisonous anywhere in the tree. The fragrant flowers even get dried for a calming tea, and the young leaves are tender enough to eat.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Got a curious cat? No problem, since the ASPCA lists linden as non-toxic to cats. A big mouthful of any plant might upset a stomach for a bit, but there's honestly no poison in this tree.
Dogs None
Dogs are fine here too, since there's nothing toxic in the leaves, bark, or flowers. If one chews on a fallen branch, it's really no big deal.
Horses None
Horses can browse a linden and come to no harm, and it's on the ASPCA non-toxic list for them. Even the young leaves and flowers make safe forage.
Rabbits Safe
Rabbits can chew away on the leaves and twigs, and there's no toxic risk at all. Linden's a common browse plant, and that tender spring growth is perfectly safe for them.
Livestock Safe
Cattle, goats, and sheep can graze the foliage without any trouble, since there's nothing in the tree that bothers them. People have cut linden for fodder forever with no issues.
Birds Safe
Birds nest in the canopy and feed around the flowers, and they're never in any danger. The seeds and buds don't pose a toxic threat either.
People Safe
Linden's safe for people too, and the fragrant flowers even get dried for a soothing tea while the young leaves are tender enough to eat. There's nothing on the tree you need to steer clear of.
No special handling precautions; honeydew from aphids can make surfaces under the tree sticky but is not toxic.
Varieties
There are a few linden forms worth knowing about, from compact native picks to silver-leaved cousins. These are the ones you'll run into most in yards and along the street.
Tilia americana 'Redmond'
This one's a tighter, more pyramidal take on the native tree that stops around 40 to 60 feet, and that neat shape is why it's such a favorite for formal shade and street planting.
Tilia cordata 'Greenspire'
It's a littleleaf linden with small heart-shaped leaves of 1 to 3 inches and a dense oval crown, and it's a tough, city-proof street tree that's loved across Europe and beyond.
Tilia tomentosa
This is the silver linden, and its dark green leaves flip up their white woolly undersides whenever the wind catches them, so the whole tree seems to shimmer.
How to propagate
There's more than one way to start a linden, and which you pick depends on what you're going for, from slow seed to grafting for named cultivars to those suckers the tree hands out for free.
SeedDemanding
Sow cleaned seed outdoors in fall, or stratify for sowing in spring · 1-2 years or more to germinate
Want to grow linden from seed? Then get comfortable with waiting. The seeds have a hard coat and a double dormancy, so even with warm-then-cold stratification they can sit for one to two years before they sprout, and they come up slow and patchy. Sow cleaned seed outdoors in fall, or stratify it for a spring sowing, and just don't count on anything fast.
GraftingDemanding
Late winter for bench grafting or summer for budding · 1 growing season to take
Named cultivars like 'Redmond' and 'Greenspire' won't come true from seed, so the trick is to graft or bud them onto seedling rootstock instead. Bench graft in late winter or bud in summer, and if it takes, the union knits together over one growing season.
LayeringModerate
Spring · 1-2 years to root
Here's a handy one: basswood sends up sprouts and suckers from its base all on its own, which hands you an easy clone. In spring, pin a low branch down to the ground to layer it, or lift a rooted sucker, and then give it one to two years to grow its own roots before you move it.
Myths
Linden trees are poisonous to dogs and cats.
Not so, since the ASPCA lists linden as non-toxic to dogs, cats, and horses, with nothing toxic in any part of it. Sure, a pet that wolfs down a lot of any plant might get a mild tummyache, but there's nothing poisonous about a linden.
That sticky black coating on basswood leaves is a disease killing the tree.
Nope, it's just aphid honeydew with a harmless sooty mold feeding on the sugar. It looks scary, sure, but it's purely cosmetic, and it clears up on its own once the aphids are handled. An established tree never gets hurt by it.