Also known as
Whitethorn, white hawthorn
Where is it originally from?
What does it look like?
Deciduous shrub or small tree (<10 m tall) with much-branched stems that are hairless, reddish-brown when young, but become grey when mature and have stiff spines to 12 mm long. Hairless triangular leaves (35-50 x 35-45 mm) with 3-7 deep lobes are solitary on long shoots, clustered on short shoots, and are often chewed by slugs. Dense flat clusters of 6-15 sweet-scented, white (rarely reddish-pink) 5-petalled flowers (10-15 mm diameter, Oct-Nov) are followed by round, shiny, crimson berries (7-11 mm diameter, Dec-Apr) with little flesh around a single stone.
Are there any similar species?
Other cultivars, especially Crataegus laevigata (usually grown as pink, double flowered cultivars), barberry and boxthorn are similar.
Why is it weedy?
Produces many long-lived, well dispersed seeds, is extremely tough and versatile, long-lived, tolerates hot to cold temperatures, damp to dry conditions, salt, wind, heavy damage, most soils, and semi-shade.
How does it spread?
Birds, and occasionally soil and water movement. Hedges, poor pastures, roadsides, and waste places are all seed sources.
What damage does it do?
Crowds out most other species, forms dense (occasionally pure) thickets, preventing the establishment of native plant seedlings.
Which habitats is it likely to invade?
Disturbed forest, shrubland and margins, fernland, wetland margins, short tussockland, other low-growing habitats, and cliffs.
What can I do to get rid of it?
1. Dig out small plants (all year round). Leave on site to rot down.
2. Stump swab (all year round): metsulfuron-methyl 600g/kg (5g/L) or triclopyr 600 EC (50ml/L) or a product containing 100g picloram+300g triclopyr/L (250ml/L).
3. Cut and squirt (all year round): Make 1 cut every 100 mm around the trunk, apply metsulfuron-methyl 600g/kg (2g mixed into a slurry with water) to each cut.
4. Frilling: with a sharp chisel or axe, make a deep cut into the sapwood at regular intervals around the base of the tree, taking care not to ring-bark the plant. Immediately apply 1.5ml of a product containing 100g picloram+300g triclopyr/L (undiluted) to each cut using a paintbrush or a squeeze bottle.
5. Spray (full leaf and actively growing stage only): metsulfuron-methyl 600g/kg (7.5g/15L (knapsack) or 35g/100L (spraygun)). Full coverage of foliage required.
What can I do to stop it coming back?
Cut stumps and severed roots resprout. Plants prefer disturbed soils, are slow to die and decompose. Avoid temptation to clear, burn or otherwise disturb soil. Maintain humus and groundcover. Plant dense species where possible to minimise seeding.