Botanical name: Veronica filiformis
Family name: Plantaginaceae
Overview
Creeping speedwell was once considered a member of the Scrophulariaceae family but was recently placed into the Plantaginaceae family along with the other speedwells.
It is a major problem in turf wherever it grows. Fortunately, it is only found in some parts of New Zealand at present, especially Palmerston North and Auckland. However, it is slowly spreading throughout the country.
Creeping speedwell is a perennial weed that forms stolons. These allow thick mats of the weed to form in turf, and the small size of the weed allows it to easily escape being mown. It is tolerant of most turf herbicides and is one of the few weeds to survive applications of triclopyr and picloram (Victory Gold).
It is thought that creeping speedwell forms no seeds under New Zealand conditions, unlike the other common speedwell species. This is probably why it hasn’t spread further throughout the country yet. It presumably gets moved around in clods of soil on people's footwear and on equipment.
Distinguishing features
Creeping speedwell has small, kidney-shaped leaves which are quite hairy. Another speedwell species with stolons is turf speedwell, but the leaf shape is different in this, and it tends not to be hairy.
When flowering, creeping speedwell has fairly large bluish flowers on long stalks, whereas turf speedwell has whitish flowers with no stalks. Creeping speedwell is a more aggressive weed than turf speedwell, forming much denser mats.
The flowers of creeping speedwell look very similar to scrambling speedwell, but this annual weed has larger leaves and it is seldom found in turf.
Control
The herbicides tolerated by creeping speedwell include clopyralid, dicamba, picloram, MCPA and 2,4-D. The best way of controlling creeping speedwell is to apply a mecoprop/ioxynil mixture, which is available as Image. It should be applied in spring or autumn, and usually needs to be reapplied six months later to kill off any regrowth.
Another possibility is to try diflufenican (Quantum) which is now formulated for turf weed control in herbicide mixes such as Bow & Arrow NZ.
Similar species
Field speedwell
Field speedwell has hairy leaves and grows small blue flowers.
Hydrocotyle
The hydrocotyle genus has 15 species with similar biology and control that are difficult to differentiate.
Pennyroyal
Pennyroyal has creeping stems and leaves that, when crushed, smell like mint.
Selfheal
Selfheal has creeping stems and dark blue flowers.
Suckling clover
Suckling clover is a winter annual and is smaller than other clover species.
Wireweed
Wireweed is a summer annual that is variable under different growing conditions.