There are four species of speedwell commonly seen in gardens. All are low-growing, creeping or sprawling plants with blue flowers. The main distinguishing features of each species are:  

Slender speedwell (Veronica filiformis) is a perennial with thin, reddish, creeping stems up to 50cm (20in) long and small, bright green, rounded leaves with toothed margins. Single, pale lilac-blue flowers appear on long stalks from the base of upper leaves from April to July. This is the most common and most vigorous of the species. 

Germander speedwell (Veronica chamaedrys) is larger and more upright than the others, growing to around 40cm (16in) tall, and is perennial. Its crimson stems have opposite lines of white hairs and the leaves are dark green, pointed and toothed. Bright blue flowers with a white centre appear in clusters between March and July from the base of upper leaves.   

Ivy-leaved speedwell (Veronica hederifolia) is noticeably hairier than the others, with sprawling hairy stems that are branched at the base of the plant and hairy, pale green, kidney-shaped leaves. Pale lilac-blue flowers appear from March to August on short stalks. This perennial species is most commonly found in shady spots.  

Thyme-leaved speedwell (Veronica serpyllifolia) is an annual and only grows to around 10cm (4in) tall, but has stems up to 30cm (1ft) long. The leaves are light green, oval and only slightly toothed. Pale blue flowers with purple veins are held in clusters at the end of each hairless stem from March to October. This species is most commonly found in moist soil.

It is not, however, necessary to be able to tell exactly which species of speedwell you have in your garden, as they all grow and can be managed in a similar way, if needed.

Speedwells are wildflowers, commonly found in open grassland throughout the UK. While their attractive flowers make a cheerful addition to meadows, flower-rich lawns and the average domestic lawn, speedwells are often seen as weeds by gardeners maintaining fine turf containing only lawn grass species. This is because their stems readily root along their length, creating dense patches able to survive regular mowing. They can also be troublesome in borders when growing alongside young or small plants.  

However, the mat-forming growth of speedwells provides cover for ground-active invertebrates and helps prevent soil erosion on bare soil. The UK native species provide nectar for solitary bees, while the germander speedwell is also a favourite food plant of caterpillars of the heath fritillary butterfly – so, in the right spot, speedwells are a great way to boost the biodiversity of your garden.

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A heath fritillary butterfly

Here are our answers to your most common questions about dealing with speedwell:

How invasive is speedwell? 

Most speedwells spread by creeping stems, rather than seed, so individual plants can be easily removed from borders to prevent the weed spreading.  

However, speedwell in lawns is often not noticed until it is well-established and it can then be tricky to remove completely. Mowing tends to scatter sections of stem, which can root into new areas of lawn, and birds spread the stems in spring when gathering moss and thatch for nest building. The good news is that speedwell doesn’t compete well with vigorous, healthy grass, so tweaking your lawn maintenance regime is often all that’s needed to prevent the weed taking hold.  

Do I need to get rid of speedwell? 

What is the easiest way to kill speedwell?       

• Pull or fork out mature plants – grasp all the sprawling stems together and pull to remove the bulk of the weed. If the stems have rooted along their length, make sure to pull out their roots too. If you’d prefer, insert a hand fork under the base of the weed and lift it from the soil. 
• Hoe off seedlings – if seedlings appear, hoe regularly to stop them becoming established. Do this on a dry, sunny day so uprooted plants shrivel and die, rather than re-rooting. Hoeing removes weeds with minimal soil disturbance.  
• Smother seedlings – apply a mulch to your soil in early spring to smother emerging seedlings. Use a bulky organic matter, such as bark chips, and apply a thick layer around 8cm (3in) deep for best effect. Alternatively, fill gaps in borders with ground cover plants.

• Improve the health of your lawn – speedwell is less able to take hold in dense, healthy grass. Follow a programme of lawn maintenance in spring/summer and autumn to boost the vigour of your lawn.  
• Raise the cutting height on your mower – leave grass slightly longer than normal to smother the weed and reduce its spread. 
• Dig out individual plants and re-seed – if you have the odd patch of speedwell in an otherwise healthy lawn, dig it out using a sharp spade and repair the lawn by re-seeding. Target your spade at the base of the weed to minimise soil disturbance and be sure to remove all the sprawling stems, or the weed could re-establish.

Should I use a weedkiller?