Slippery Elm

Ulmus rubra

tree

Slippery elm (Ulmus rubra) is a medium native elm, 40 to 70 ft tall, with a spreading, vase-shaped crown, rough dark leaves, and a reddish, mucilaginous inner bark that gives it its name. That soft, slippery inner bark has long been harvested and dried to a powder. Because demand has pressured wild trees - and because Dutch elm disease kills many - it is best grown deliberately and harvested ethically, taking bark from prunings and thinnings rather than felling wild trees. It is a tough, fast tree of moist woods and bottomlands, long-lived where disease spares it.

✅ Plant alongside

Good neighbors that attract beneficial insects or deter pests

• Comfrey — A deep-rooted herb for the moist ground beneath, good for mulch and feeding the soil
• Bee Balm — A pollinator plant that fills the partly shaded edge of the tree well
• Elderberry — A moisture-loving shrub that shares the rich, damp bottomland conditions

🛡️ Pest & disease prevention

Proactive ways to stop trouble before it starts — tap a name with an arrow for its full guide

• Dutch elm disease →

  Keep trees vigorous, prune only in the dormant season, and remove and destroy any wilting, dying branches at once

• Elm leafminer →

  Pick and destroy mined leaves; established trees tolerate light damage

• Bark beetles →

  These spread elm disease - remove dead wood and stressed limbs that attract them

🌾 Harvest & storage

Harvest the inner bark in spring when the sap is running and the bark separates easily. The ethical way is to take it from branches removed during pruning or from thinned trees, never by ringing the trunk of a standing tree, which kills it. Peel the outer bark away, then strip the soft, fibrous, mucilaginous inner bark and dry it completely; it is then ground to powder. A little goes a long way, so a few pruned limbs supply plenty.

🥗 Nutrition & benefits

Slippery elm is grown for its inner bark, traditionally dried and powdered into a bland, mucilaginous gruel or stirred into water - historically also a survival food for its starch and slip. It is not eaten as a vegetable. Growing your own and harvesting only from prunings takes pressure off wild stands, which are squeezed by both overharvest and disease.