Veronica longifolia Seeds | Garden Speedwell
LATIN NAME: Veronica longifolia
COMMON NAME: Garden Speedwell
Plant Profile
Garden speedwell is a tall, upright perennial, 60-120 cm, with whorled leaves and dense tapering spikes of blue-violet flowers from July to September. The spikes open from the bottom upward and stay in colour for weeks, which makes the plant one of the most reliable late-summer blues.
The habit is stiff and vertical, with several stems rising from a slowly spreading crown, and the foliage stays low and green at the base through most of the season. The plant is a strong vertical accent in a border that would otherwise be all mounds and domes.
Veronica longifolia comes from damp meadows and riverbanks across Europe and northern Asia. In the garden it prefers moisture but tolerates ordinary soil, and it is one of the few tall perennials that will flower in light shade.
Science & Biotechnology
Veronica is a large genus, and its taxonomy has been rewritten by molecular work: the speedwells were moved from their own family into the Plantaginaceae, alongside the plantains, which look nothing like them. The change is a good reminder that flower form is not a reliable guide to relatedness.
The blue colour comes from anthocyanins complexed with metal ions, and the shade shifts with soil pH and with the age of the flower. That is why the same clone can look violet in one garden and clear blue in another.
Speedwells are pollinated by short-tongued bees and hoverflies, and the flower shape is a good example of a generalist design: the tube is shallow enough for many insects, and the landing platform is wide. That is why a stand of veronica in July is busy with insects at a time when the border has little else to offer.
Uses & Benefits
Garden speedwell is a border plant for the middle or back of a moist bed, where its blue spikes work with heleniums, persicarias and the taller grasses. It is also a cut flower, and the spikes last a week in water.
In a wild garden it is a good nectar plant, and it is one of the few tall perennials that will grow in damp shade. Commercially the species is sold as a garden perennial, and several named selections exist with deeper colour or a more compact habit. In a vase the spikes keep their blue without dropping, and they dry well enough for winter work.
Growing from Seed
Sow on the surface at 18-20°C; germination takes two to three weeks and light improves it. Cold stratification for three weeks is helpful with older seed. The seedlings are small and slow at first, so prick them out carefully.
Plant out at 40 cm apart in sun or light shade, in soil that holds some moisture. Water through dry spells in the first summer. Cut the spent spikes back to the basal growth to encourage a second, shorter flush, and divide the clumps every three years in spring. Tall plants may need a light stake in exposed sites.
Our Take
A blue that keeps going into September, on a plant that tolerates the damp shade where little else flowers. Give it moisture and it will give you a second flush.
Related Reading
Continue exploring with these related plants: