Holm Oak
Quercus ilex
Clips into a hedge or grows on into a large tree, and drought barely registers either way.
- Type
- Tree · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green · Silver and gray
- Sunlight
- Full sun to partial shade, with full sun the better of the two.
- Watering
- Dry ground is no obstacle once it is established.
- Feeding
- Young hedges appreciate a spring feed; mature trees rarely need one.
- Frost tolerant
- Yes
- Flowering
- May
- Pruning
- Hedges get one clip in August; specimen trees need barely any pruning.
- Apr–May Spring Growth
- May–May Leaf Fall
- May–Oct Flowering
- Oct–Dec Growing
- Jan–Apr Growing
- Plant spacing
- 26 ft 3 in
- In-row spacing
- 26 ft 3 in
- Between rows
- 32 ft 10 in
- Square-foot density
- Not suited to SFG
- Root system
- Woody, with a taproot it keeps
- Working depth
- 24 in–5 ft
- Can reach
- 10 ft down where the soil allows
- Spread
- 39–66 ft across, about 1.5–2.5× the width of the plant
It anchors downwards as well as sideways, which is what lets it stand in a gale and what makes it hate being moved. Plant it small: past a few years in the ground a taprooted tree transplants badly, and often not at all.
The habit is Holm Oak’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.
- Scale insects Immobile brown or white bumps fixed to stems and leaf undersides, sucking sap and weakening growth. Wipe off with a damp cloth or dab with horticultural soap; watch for the sooty mold that follows.
- Phytophthora root and foot rot A waterborne rot of woody plants that kills from the roots up: the whole plant fades and wilts, and the bark at the base is stained rusty-brown beneath.
- Oak processionary moth
Beneficial predators that hunt this plant's pests — grow their favourite flowers nearby to recruit them. companion plant
- Hoverfly SyrphidaeHunts Scale insects
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) CoccinellidaeHunts Scale insects
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.
Yew, Bay Laurel, Portuguese Laurel, Beech
Trees, like this one.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com