Hackberry
Celtis occidentalis
also called common hackberry, sugarberry, nettle tree
The unglamorous workhorse of tough sites: an elm-shaped native with corky warted bark that takes drought, wind, alkaline clay and city air, and feeds the winter birds while it does it.
- Type
- Tree · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green · Gold and chartreuse
- Flower color
- Orange
- Sunlight
- Full sun
- Watering
- Low once established
- Soil
- Any: clay, sand, alkaline, compacted, droughty or wet
- Feeding
- All-purpose balanced
- USDA zones
- 3a–9b
- 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
- 98–148 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 Hackberry’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 by you: the berries are the birds' winter larder. Prune in winter if at all.
- What to look for
- The small drupes turn dark orange-brown and sweet in early fall and hold on the twigs into late winter.
- How to harvest
- Taste a few sugarberries if you are curious (thin sweet flesh over a big seed), then leave the crop where it is. Prune only for deadwood and clearance.
- How often
- A look each winter; the tree needs almost nothing.
- Storing the crop
- Nothing to store. The witches' brooms and leaf galls are permanent tenants — cosmetic, harmless, and not a reason to spray.
Beneficial predators that hunt this plant's pests — grow their favourite flowers nearby to recruit them. companion plant
- Assassin bug ReduviidaeHunts Lace bugs
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.
- Green lacewing Chrysoperla carneaHunts Lace bugs
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.
- Ladybird (lady beetle) CoccinellidaeHunts Psyllids
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 Lace bugs
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.
The small orange-brown berries are technically drupes, sweet and edible, and cedar waxwings, robins and mockingbirds strip the tree of them through winter. It is also a host tree for hackberry emperor, mourning cloak and question mark butterflies.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com