Taxodium distichum Seeds | Bald Cypress

Bald Cypress (Taxodium distichum) seed — Bald Cypress (*Taxodium distichum*): Cupressaceae (cypress family), formerly placed in Taxodiaceae, native to The Atlantic and Gulf coastal plain of the United States from Delaware and Maryland south to Florida and west to eastern Texas, and up the Mississippi valley as far as southern Illinois and south-western Indiana — in swamps, sloughs, river floodplains and other wet ground.

LATIN NAME: Taxodium distichum

COMMON NAME: Bald Cypress, Swamp Cypress, Southern Cypress

Plant Profile

Bald cypress is the tree that breaks the rule about conifers. Each autumn the light green foliage turns a rusty copper, and then the whole shoot falls — not leaf by leaf, but as a complete short branchlet with the needles still attached. The ground under a swamp stand is covered in these little feathered twigs, which is why the tree looks dead by December and bare until the following April. The leaves themselves are soft, flat, two-ranked and barely longer than a fingernail, so the whole crown has a feathery, almost fern-like texture.

Two structures mark the species in wet ground. The first is the swollen, fluted base of the trunk, which spreads into broad buttresses and anchors a heavy tree in soft mud. The second is the knee: a woody, blunt-topped projection that rises from the roots, sometimes to the height of a person’s chest, sometimes barely breaking the surface. In a dry site you may find none at all. Where the water is permanent, an old stand produces them by the thousand and a visitor has to pick a path between them.

Bald cypress reached Europe early, grown in London by the 1640s from material collected in the American colonies, and it has been planted in European parks and floodplain forests ever since. It grows surprisingly well in the cool, wet soils of central Europe and in the British Isles, where the summers are milder and shorter than in its native south, and its ability to sit in standing water for part of the year makes it useful ground that will carry little else.

The cones are round, a couple of centimetres across, green ripening to brown, and they sit on short stalks with a scaly pattern that reads as two halves. Two seeds develop behind each scale and they carry a resinous coat and a small wing. Because the seed is light and survives a soaking, it travels on the surface of the flood as well as in the wind, which is how the species reaches the next slough downstream, and how it has colonised new ground after a major flood.

Science & Biotechnology

The heartwood is one of the most durable timbers of North America, and the chemistry behind it attracted attention long before the pharmacology. Extracts of the wood yielded the diterpenoid quinones taxodione and taxodone, which were reported from the species in the 1960s and taken into early antitumour screening programmes, where they showed activity against some experimental tumours. The same resinous fraction is what makes the timber resistant to decay in water and in soil.

Uses & Benefits

Because the wood lasts, the old logs last too. When the southern cypress forests were cut in the nineteenth and early twentieth centuries, a large fraction of the timber was lost from rafts and barges and sank in the rivers, where a century of slow water has left the logs in excellent condition. Salvage operators now raise them with divers and cranes, and sinker cypress, milled from sunken timber, is sold as a premium wood for flooring and furniture, at prices no standing tree can match.

Growing from Seed

A seed will lie where it falls until the water drops and exposes a patch of wet mineral soil, and only then will it establish. That is why the natural stands sit in bands along the flooded margins of a swamp rather than in the middle of the water, and why the pattern of a cypress swamp is a record of old water levels. In deep, permanent water the tree can grow only where a hummock, a logging track or a fallen trunk gives it a start.

Buy or collect fresh seed if you can, because it does not keep well once it has been dried hard; if you must store it, keep it cold and damp, even in water, rather than in a warm cupboard. Sow two centimetres deep in a heavy mix of two parts loam to one part coarse grit or river sand, and keep the pan standing in a shallow tray of water so the medium never dries out. Warmth and constant moisture together give the best emergence. The species is a wetland tree from the start, and a seedling allowed to dry out in its first weeks will not recover.

Move the seedlings into deep pots as soon as the stems stand a few centimetres, setting the collar just below the surface, and keep them in shallow water through the first summer. The root is eager and straight, and a plant left too long in a seed tray will kink. Plant out in autumn or early spring into any soil that stays moist, in full sun, and water through the first two summers until the roots reach the water table. Mulch well and do not feed heavily; the tree is not demanding but it is thirsty. Protect young plants from deer and from late frost in the first winter, and by the second year the leader will run.

Our Take

There is no easier tree for wet ground, and the autumn colour is worth the space on its own. For a smaller garden, the narrow selection sold as pond cypress fits a tighter corner, and dawn redwood gives a faster, lighter, equally deciduous conifer for ordinary soil. Chinese swamp cypress is the rarest of the group and a collector’s plant. Keep the pan wet, keep the roots cool, and give it room to spread its base.

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