Once established V. spicata spreads mainly by rhizomes and stolons into areas of bare soil where it grows in dense patches. Veronica spicata is higly intolerant of shade and competition, persisting only where potentially tall competitors remain restricted by relative harshness of environment. In Finland , V. spicata is at the northern limits of its distribution. The sites of occurrence are very dry, often facing south or south-west, on rocky outcrops and the surrounding shallow soils. Veronica spicata is one of the two host plants used by the Glanville fritillary butterfly (Melitaea cinxia) in the Åland islands, where it mainly occurs in the west, north-west and north of the archipelago.