If you have noticed small blue flowers appearing in patches across your lawn, you are almost certainly looking at speedwell. There are several species that establish themselves in Irish lawns, the most common being slender speedwell (Veronica filiformis) and germander speedwell (Veronica chamaedrys), though field speedwell turns up too, particularly on bare or recently disturbed ground. They are low-growing, they survive the mower easily, they spread steadily through the season, and they produce a flower that is, by any honest measure, rather beautiful. The instinct for many gardeners is to treat them as a problem. I would ask you to pause before acting on that instinct, because the question of what to do about speedwell in an Irish lawn is worth thinking through properly.

Slender speedwell, the most frequent culprit in closely mown lawns, forms a creeping mat of small rounded leaves with pale blue flowers that appear from spring through early summer. It roots at the nodes as it spreads, which is why it tends to form defined patches rather than appearing evenly across the whole lawn. Germander speedwell is slightly more upright, with a deeper sky-blue flower and two rows of fine hairs running down either side of the stem. Both are perennials. Once established, they are not going anywhere without deliberate intervention. Neither of them is a native Irish plant in the strictest sense, but both have been naturalised here for generations and both provide a useful early nectar source for bees and other pollinators at a time of year when garden flowers are still sparse.

The reason speedwell takes hold where it does tells you something useful about those parts of your lawn. It favours areas where the grass sward is thin, where the soil is slightly compacted or low in fertility, or where shade has weakened the grass enough to create gaps it can exploit. A dense, well-fed lawn growing in reasonable soil is actually quite good at competing with speedwell and keeping it in check. So if you have significant patches appearing, the most honest response is to ask what those patches are telling you about the grass, rather than simply trying to suppress the speedwell itself. Improving drainage, relieving compaction with a garden fork, overseeding thin areas in autumn, and feeding the lawn properly through the growing season will all do more lasting good than any attempt to eliminate speedwell directly. Address the conditions and the grass will gradually outcompete it on its own terms.

The soil beneath the lawn matters here as much as the grass above it. A lawn sitting on compacted, biologically depleted or poorly structured ground will always struggle to maintain the dense sward that keeps opportunist plants at bay. Improving the soil is the most direct way to improve the lawn, and it is where the Lush Lawns programme starts. It is built around a soil-first approach to lawn health, covering feeding, structure and what to do at each point in the Irish lawn calendar to build a lawn that can genuinely look after itself. If speedwell is appearing across a significant area, that is a signal worth responding to at soil level rather than surface level. The Lush Lawns programme covers the full approach, and the results are better and longer-lasting than anything that comes from a spray or a single application of feed.

The broader question behind all of this is what you actually want your lawn to be. The idea of a pure grass sward, uninterrupted by any other plant, is a relatively recent and heavily marketed ideal. It requires consistent chemical input, significant ongoing effort, and plenty of cost. An Irish lawn with clover, self-heal, speedwell and the occasional daisy in it is not a neglected lawn. It is a lawn that is doing something useful for the insects and birds that depend on your garden as well as looking after itself. The two things are not in conflict. You can have a lawn that is tidy, well-kept, clearly managed, and still contains a range of low-growing plants that add colour and support wildlife. Most people who look at a lawn with speedwell in flower are not thinking it looks unkempt. They are thinking it looks like a garden that is alive.

If you have decided you genuinely cannot accept the speedwell and want it reduced, I do not use or recommend weedkiller of any kind, selective or otherwise. The damage that herbicides do to soil biology, to pollinators, and to the wider ecology of a garden is not a trade-off I am willing to make for the sake of a uniform sward. The practical approach for smaller patches is hand removal with a trowel or hand fork, working carefully to lift the rooted stems out rather than simply tearing off the top growth. Where you remove it, rake the soil lightly and overseed straight away, because bare ground is exactly the condition speedwell uses to reestablish. For larger areas, there is no quick fix. Raising the mowing height slightly, overseeding in September, and improving the underlying fertility of the soil is a slower process, but it is the one that actually works without cost to the garden around it.