Eastern cottonwood
Populus deltoides
also called cottonwood, eastern poplar, necklace poplar
The great shade tree of the Plains, where it was often the only tree for miles: glossy triangle leaves that flash and rustle in any breath of wind, on a trunk that gets enormous faster than anything else native.
- Type
- Tree · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Sunlight
- Full sun
- Watering
- High; a river tree that hunts water
- Soil
- Moist bottomland for preference; any soil with water in reach
- Feeding
- All-purpose balanced
- USDA zones
- 3a–9a
- Frost tolerant
- Yes
- Plant out
- 14 days before the last spring frost
- Plant spacing
- 49 ft 3 in
- In-row spacing
- 39 ft 4 in
- Between rows
- 59 ft 1 in
- Square-foot density
- Not suited to SFG
- Root system
- Woody, shallow, wide and opportunistic
- Working depth
- 12–24 in
- Can reach
- 3.5 ft down where the soil allows
- Spread
- 197–262 ft across, about 3–4× the width of the plant
These roots go looking, and what they find is drains, soakaways, footings, paving and the border next door. Give it real distance from anything you would mind being lifted or blocked: the reach below ground is several times what the crown suggests.
Fast, thirsty and shallow, with roots that reach drains and footings from a long way off and suckers that come up through a lawn. A tree for the far end of a big property.
The habit is Eastern cottonwood’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.
- When
- Not harvested. The calendar is structural: prune young, inspect old.
- What to look for
- Narrow forks and competing leaders in the first decade; deadwood over anything valuable ever after.
- How to harvest
- Buy or keep only a male clone if the June cotton would madden you. Prune to one leader with wide-angled limbs while cuts are small, then have a big one inspected professionally every few years; it makes limbs faster than it makes strong wood.
- How often
- Annually while young; a professional look every three to five years at maturity.
- Storing the crop
- Nothing to store. Plant it a full tree-length from anything it could fall on, and it will be the best thing on the horizon for fifty years.
- Canker Canker diseases in the fast soft wood as it ages
- Brittle limbs shed in wind and ice storms; site it where that costs nothing
- Cottonwood borer at the base of stressed trees
State tree of Kansas, Nebraska and Wyoming. The June "cotton" storms come only from female trees, so a cottonless male clone is the neighborly choice. This is a tree for acreage and windbreaks; in a small yard its speed, thirst and brittle limbs are all liabilities.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com