Veronica, often called Speedwell, is a favourite perennial border plant flowering from summer through to autumn. It is a great plant for attracting bees, butterflies and birds and with its tall flower spikes and deep green foliage is an excellent accent plant. Veronica blooms for an unusually long time for a perennial.
There are about 500 species of Veronica making it the largest genus in the flowering plant Plantaginaceae. The species are herbaceous annuals or perennials that are easy to grow. Veronicas begin flowering in early summer and continue for a long time through autumn. They come in different sizes and types, ranging from small ground huggers to taller clump forming ones with impressive flower.
Gardeners who love the colour blue know that veronica provides some of the clearest, truest blues in the perennial border. Other flower colours are also available, including pink, rose and white. Veronicas have flower spikes that are composed of dozens of densely arranged, small florets, that open progressively from the base upwards to form a long lasting spike.
I love using this very versatile plant along my garden paths and in the seating areas, where butterflies can collect on this long-blooming flower.
Although low-growing varieties are available, the most common veronicas form attractive 30cm to 90cm tall mounds. Narrow spikes of tiny flowers adorn the plant in midsummer and are superb in bouquets.
The lower spreading varieties seldom exceed 10cm in height and are a very good groundcover addition in your garden.
Veronica can be a workhorse in the cut flower garden; it will provide a full second crop of stems if cut down completely to the ground after the first harvest. Veronica is a spiky or linear type flower that provides movement, action, or life to an arrangement, and is long lasting in the vase.
Veronica likes full sun in well-drained soil, and although it will tolerate some shade, the stems may flop a bit in that environment. In the USA Veronica is happy in Zones 3 to 8.
Transplant garden centre potted plants anytime during the growing season. Choose an overcast day or plant in the evening to minimize stress from the sun on the transplant. Space plants 30cm to 60cm apart, depending on the variety. Prepare the garden bed by using a garden fork or tiller to loosen the soil to a depth of 30cm, then mix in a 5cm to 10cm layer of compost. Dig a hole twice the diameter of the pot the plant is in. Carefully remove the plant from its container and place it in the hole so the top of the root ball is level with the soil surface. Carefully fill in around the root ball and firm the soil gently. Water thoroughly.
Veronicas must be watered regularly for best results. Apply a thin layer of compost each spring, followed by a 2cm layer of mulch to retain moisture and control weeds. Water plants during the summer if rainfall is less than 25mm per week. Stake tall varieties to keep them upright. After the first killing frost, cut stems back to between 25m and 50mm above the soil line. Divide plants every 3 to 4 years as new growth begins in the spring, lifting plants and dividing them into clumps.
The most common diseases afflicting Veronicas are fungal diseases characterized by powdery mildew appearing initially on the leaves. Diseases can be minimized by avoiding overcrowded spacing of plants and by carefully picking off affected leaves as soon as symptoms are evident. You can also apply fungicides as soon as symptoms are visible. Samples of fungicides to use are horticultural oil, sulphur, potassium bicarbonate and thiophanate-methyl. Check the labels for correct dosage.
Coreopsis: Zagreb coreopsis has strong yellow daisy flowers over thread-like leaves that combine well with ‘Blue Peter’ veronica in sun.
Lady’s mantle: The chartreuse foamy flower sprays of Lady’s Mantle are an attractive foil for Sunny Border Blue veronica in early summer.
Salvia: Echo the vertical spikes of violet Blue Salvia with the vertical spikes of white Icicle veronica. They enjoy similar situations.
Hemerocallis (Daylilies): An incredible assortment of flower sizes and colours, bloom times and plant heights means that there’s a daylily for nearly any landscape situation! Try them in mixed shrub or perennial plantings, or naturalised in open areas. Long-lived and easy to grow.
Rudbeckia (Black-eyed Susan): Vibrant daisy flowers are classic summer beauties that attract butterflies and make beautiful cut flower arrangements. Native to North America, they are well-suited for the meadow or wildflower garden, and for naturalising. Combines well with Aster, Butterfly Bush and Echinacea. Heat tolerant.
Shasta Daisy: Beautiful daisy flowers are great for summer bouquets. Also attractive in butterfly gardens, or combined with other perennials such as Iris, Poppy, Daylily or Yarrow. Remove faded flowers down to the next visible bud to promote re-bloom.
SOME FAVOURITE VERONICAS
Red Fox Veronica: Perfect variety for borders and naturalised areas, this deep rose-red variety won’t overwhelm existing plantings — grows to 30cm to 45cm in height with an equal spread. Dense flower spikes attract butterflies with blooms all summer long. Zones 3-8.
Crater Lake Blue veronica (Veronica austriaca ‘Crater Lake Blue’): Bears deep blue flowers in early summer on 45cm-tall plants. Zones 6-8.
Georgia Blue veronica (Veronica ‘Georgia Blue’): Develops large mats of toothed purple-tinged foliage. Racemes of small saucer-shaped white-eyed deep blue flowers bloom from early spring into summer. It grows 30cm tall. Hardy in Zones 6-8.
Giles Van Hees veronica (Veronica ‘Giles Van Hees’) has lance-shaped foliage and dense spikes of bright pink flowers in summer. It grows 15cm tall. Hardy in Zones 4-8.
Veronica (‘Ulster Blue Dwarf’): Blooms on a compact 30cm plant. This favourite Veronica is loved for its profusion of intense violet blue flowers all summer long. Wonderful as a border or container plant. Remove faded flowers to promote even more blooms. Rabbit resistant. Blooms mid to late season.
Icicle veronica (Veronica spicata ‘Icicle’) bears pure white flowers on spikes to 60cm tall. Zones 3-8.
Sunny Border Blue veronica (Veronica ‘Sunny Border Blue’) is one of the best upright veronicas for sunny gardens. With glossy, dark green crumpled leaves and 18cm spires of violet flowers from early summer on, it is outstanding. It grows to 60cm tall. Hardy in Zones 4-8.
Waterperry Blue veronica (Veronica ‘Waterperry Blue’) is a groundcover type with sky-blue flowers in spring. It grows 15cm tall. Hardy in Zones 4-8.
This is not intended to be a definitive list.