Basswood

Tilia americana

also called american linden, american basswood

The American linden, a broad heart-leaved shade tree that hums audibly for two weeks in early summer: its small cream flowers are among the richest bee forage on the continent.

Light Full sun
Water Moderate
Hardiness Hardy
USDA zones 3a–8a
Height 18–25 m
Spread 45 ft 11 in
Spacing 10–12 m
Sow depth From a young tree
Root depth 12–24 in
Type
Tree · Perennial
Botanical family
Mixed / other
Foliage color
Green · Gold and chartreuse
Flower color
White
Sunlight
Full sun
Watering
Moderate
Soil
Deep, moist, fertile
Feeding
All-purpose balanced
USDA zones
3a–8a
Frost tolerant
Yes
Plant out
14 days before the last spring frost
Plant spacing
36 ft 1 in
In-row spacing
29 ft 6 in
Between rows
45 ft 11 in
Square-foot density
Not suited to SFG
Root system
Woody, shallow and far-reaching
Working depth
12–24 in
Can reach
4 ft down where the soil allows
Spread
92–138 ft across, about 2–3× the width of the plant

Almost all of a tree’s roots are in the top two feet of soil, where the air is, and they run out well past the branch tips. The deep taproot most people picture belongs to the seedling; the tree grows out of it and spends the rest of its life spreading sideways instead.

The habit is Basswood’s own; the figures are what that habit usually comes to at this size, not a measurement of this species. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.

Cats and dogs
Confirmed safe

We say a plant is safe only where a named poison-control reference names that exact species and records it as non-toxic to both cats and dogs. Most plants are on nobody’s list, and their absence here is not a judgement about them. This is a record of what those references say, not veterinary advice, and it cannot account for your own animal, the quantity eaten, or a plant treated with anything.

More about plants and pets

When
Flowers for tea in early summer, in the two humming weeks they are open.
What to look for
The small cream flowers fully open and fragrant, each cluster hanging from its odd pale wing of a bract, and the whole tree loud with bees.
How to harvest
Pick flower clusters, bract and all, from the branches you can reach on a dry morning. Spread them to dry out of the sun.
How often
Once a year, and lightly — the bees have prior claim.
Storing the crop
Dried linden flowers keep a year in a jar and make the honeyed tilleul tea of French grandmothers. The tree itself asks only a dormant-season prune while young.

Beneficial predators that hunt this plant's pests — grow their favourite flowers nearby to recruit them. companion plant

  • Garden birds Passeriformes

    Both things are true: birds strip your currants and a brood of blue tits takes several thousand caterpillars out of one fruit tree in a fortnight. Net what you must and welcome them everywhere else — a nest box near the apples is worth more than a spray.

  • Assassin bug Reduviidae

    A patient ambusher with a curved beak it drives into whatever it catches — caterpillars, beetles, bugs, and the occasional bee, so count it a generalist rather than a specialist. It will jab a careless finger too, so admire it and leave it be.

  • Praying mantis Mantidae

    A sit-and-wait ambusher that snatches caterpillars, beetles, and anything else that wanders close — friend and foe alike, so count it a mixed blessing. Tall, structured plantings give it perches and egg-case anchors.

  • Tachinid fly Tachinidae

    Bristly, house-fly-lookalike parasitoids that lay eggs on caterpillars, beetle grubs, and earwigs — the maggot consumes the host from within. Adults sip nectar from shallow umbels and daisies.

  • Aphid midge Aphidoletes aphidimyza
    Hunts Aphids

    A tiny midge whose orange maggots paralyze aphids and drink them dry, twenty or more each. Sold as a greenhouse biological control and resident outdoors wherever there are small nectar flowers and an unsprayed aphid colony to find.

  • Bats Chiroptera

    A single bat takes hundreds of moths and mosquitoes in a night, and the moths are the parents of your cutworms, corn earworms and hornworms. Put up a bat box on a warm south wall, leave a night-scented corner unlit, and never spray after dark.

  • Beneficial nematodes Steinernema & Heterorhabditis spp.

    Microscopic worms watered onto damp soil that hunt down soil-dwelling grubs and release a bacterium that kills them within days. Timing is the whole thing: warm, damp soil and a small target grub, which means late summer for most of what they are used against.

  • Big-eyed bug Geocoris spp.
    Hunts Aphids

    A stubby 3 mm bug with enormous wrap-around eyes, working the soil surface and the low foliage for aphids, mites, thrips and insect eggs. It is the main natural check on chinch bugs in a lawn and it is killed outright by insecticide.

  • Damsel bug Nabidae
    Hunts Aphids

    A slender, mantis-armed bug that grabs aphids, small caterpillars, and thrips in low crops and meadowy edges. Leave a strip of unmown grasses and flowers for it to overwinter in.

  • Dragonflies & damselflies Odonata
    Hunts Aphids

    Aerial hunters that take mosquitoes, midges and small flies on the wing all day, and whose larvae spend a year or more clearing the same insects from the water. A pond with planted margins and no fish is the way to have them.

  • Green lacewing Chrysoperla carnea
    Hunts Aphids

    Its bristly larvae — "aphid lions" — impale aphids, mealybugs, thrips, and mite colonies, eating hundreds a week. Adults feed on nectar and pollen from small open flowers and overwinter in hollow stems left standing.

  • Hoverfly Syrphidae
    Hunts Aphids

    Bee-mimicking flies whose legless larvae graze aphid colonies clean while the adults pollinate. A ribbon of shallow, nectar-rich flowers kept in bloom all season recruits wave after wave of them.

  • Ladybird (lady beetle) Coccinellidae
    Hunts Aphids

    The gardener’s favorite ally: adults and their alligator-shaped larvae each eat thousands of aphids, plus scale, mealybugs, and other soft-bodied sap-suckers. Grow flat, open flowers for the adults and never spray a colony that ladybird larvae are already working.

  • Minute pirate bug Orius spp.
    Hunts Aphids

    A pinhead-sized true bug that is the best natural check on thrips, and happily spears aphids, mites, and insect eggs too. It needs pollen when prey is scarce, so keep something flowering nearby.

  • Parasitic wasps Braconidae & Trichogramma
    Hunts Aphids

    Tiny, stingless wasps that lay eggs in or on caterpillars, aphids, and moth eggs — the white cocoons riding a hornworm are their calling card, so leave that caterpillar be. Umbel flowers with shallow nectar keep the adults fuelled.

  • Soldier beetle Cantharidae
    Hunts Aphids

    Soft-winged beetles seen mating on flower heads in high summer; adults and larvae both take aphids and soft grubs. Open composite flowers are their landing pads and hunting grounds.

  • Spiders Araneae
    Hunts Aphids

    Webs, ambushes, and night patrols make spiders the garden’s steadiest generalist predators, taking whatever flies or crawls past. Mulch, ground cover, and undisturbed corners keep the population dense.

    Plant nearby LavenderThyme
  • Spined soldier bug Podisus maculiventris

    A predatory stink bug — same shield outline as the pest, but with a sharp spine at each shoulder and a beak it uses to spear caterpillars and beetle grubs. Learn the spines before you squash a shield bug, because this one is on your side.

Beekeepers park hives under flowering basswood for a varietal honey, carvers prize the soft even wood above all others, and the inner bark (the "bast" in basswood) was rope and cordage for every nation that lived among them.