Corn speedwell (Veronica arvensis) is a flowering plant and common weed native to Europe, Africa, and Asia. Corn speedwell grows as a weed in gardens, trash dumps, and pastures and gives out small blue flowers in the spring.
I. Appearance and Characteristics
Veronica arvensis, common names: wall speedwell, corn speedwell, common speedwell, rock speedwell, field speedwell, is an annual flowering plant in the plantain family Plantaginaceae. The species is native to Europe and a common weed in gardens, pastures, waste places, and cultivated land.
It is a hairy, erect to almost recumbent, annual herb, 9 to 40 centimeters (3.5 to 15.7 in) high from a taproot. The leaves are oppositely arranged in pairs about the stem. The lower leaves have short petioles; the upper are sessile. Each leaf, 1.5 to 2.5 centimeters (0.59 to 0.98 in) in length, is ovate, or triangular with a truncated or slightly cordate base, with coarse teeth. Borne in a raceme, initially compact but elongating with age, the flowers are pale blue to blue-violet, 2 to 3 mm in diameter, four-lobed with a narrow lowest lobe. Flower stalks are 0.5 to 2 millimeters (0.020 to 0.079 in) and shorter than the bracts. The fruit capsules are heart-shaped and shorter than the sepal-teeth. It flowers from April to October.
Veronica arvensis plants go through changes in their germination due to temperature and light that control the timing of growth in buried seed reserves. These plants tend to germinate in consistent temperature ranges of 10 degrees Celsius to 15 degrees Celsius. If they do not make the first autumn cycle of growth, they can grow in the following spring.
II. How to Grow and Care
Corn speedwell is a hardy, low-maintenance plant that thrives in a variety of conditions, from full sun to partial shade. It prefers well-drained soil and moderate watering, without the need for frequent fertilization. Special care points include ensuring proper spacing to avoid overcrowding and monitoring for common pests like aphids. Overall, corn speedwell is considered easy to care for, making it suitable for beginner gardeners.
Sunlight
Corn speedwell flourishes best in full sun conditions, where it receives ample light to support robust growth and maintain overall health. However, it also exhibits a good degree of adaptability, tolerating partial sun, which proves its versatility. In environments that deviate from its optimal light intensity, corn speedwell’s growth may be less vigorous and the plant could display signs of stress. When grown outdoors, corn speedwell should be situated in areas that receive direct sunlight for most of the day to ensure its vitality, but it can also manage light shade. No indoor planting advice is necessary as corn speedwell is predominantly an outdoor species.
Temperature
Corn speedwell , native to the temperate Asia and Northern Europe, prefers a warm growth environment, and is relatively cold-resistant. It is suitable for growing in the temperature range of 15 to 25 ℃. It should be noted that overwatering should be avoided in winter.
Watering
Originating from temperate regions, corn speedwell is accustomed to moderate moisture levels in its natural habitat. This species exhibits a preference for consistent soil moisture without being waterlogged, showcasing an equilibrium in its water needs. Watering every week will suffice to maintain this balance. Transitioning smoothly into care requirements, corn speedwell thrives best when grown outdoors where it can benefit from the natural rainfall patterns, aligning with its need for regular but not excessive watering. Its growth cycle is notably influenced by adequate hydration, emphasizing the importance of a well-managed watering regimen.
Soil
Corn speedwell is suitable for growing in fertile, thick, but well-drained sandy soil with an appropriate pH of 5.8 to 7.5. The mixed soil is better and can ensure good permeability. It cannot live in the soil with excessive moisture. In particularly, excessive soil moisture should be avoided in winter. The cultivating soil should be well drained and can be mixed with clay, wood fibers such as bark and coconut bran, and sand at the ratio of 3:2:2:2.
Fertilizing
Corn speedwell does not require much fertilizer, so applying a little is fine. After it enters the growth period, it is necessary to apply a small amount of water-soluble compound fertilizer with nitrogen, phosphorus and potassium at the ratio of 20-10-20. In order to promote the flowering, when corn speedwell is about to enter the flowering period, it is necessary to apply water-soluble compound fertilizer with nitrogen, phosphorus and potassium at the ratio of 10-30-20, generally 10 to 15 days before the flowering period.
Fertilizer can be reduced after early fall, as its growth speed begins to slow. Fertilization is not required in the recovery period because the nutrient absorbing ability of the injured root system is weak. Too much fertilizer can lead to an injured root system or slow growth.
Planting Instructions
Corn speedwell can be propagated by its seeds, and the seeds can be sown flowerpots or gardens. If sown in a flowerpot, it can be done in early spring. Fill the flowerpot with cultivable soil, fill a little water in a shallow pan, and place the pan at the bottom of the flowerpot, so that the water permeates the soil thoroughly and make it moist. Spread the seeds on the soil, cover with another layer of fine soil, and finally cover the flowerpot with cling film or a glass plate. The seeds will germinate in about 20 days at 20 ℃. When the seedlings grow up, you can transplant them where you want.
If sown in a garden, it should be done later, from mid-spring to late spring. After sowing, water it once and cover the surface with plastic film. The seeds can germinate in about 30 days. It is best to have appropriate shade after sowing to avoid sun exposure.
Pruning
The withered flowers of corn speedwell will not fall off from the flowering branches automatically, but still stay on the flowering branches. It is recommended that remnant flowers be removed in time to keep the plant look good, as well as to reduce unnecessary nutrient consumption, promoting the growth of underground parts.
Pruning should be done in the morning on sunny and dry days. When pruning, cut the flowering branch at the base where the last flower is in close proximity to it. Mastering the time of pruning can regulate the flowering period. In general, corn speedwell will bloom again in 20 days after pruning. After winter, when the ground temperature rises to above 0 ℃, almost early spring, the withered and yellowed parts overground should be pruned, so that it begins its growth in the new year.
Propagation
The preferred propagation method for corn speedwell is sowing during the Spring season. It is relatively easy to propagate with visible signs of successful propagation including vibrant growth and establishment of seedlings. Ensure moist soil and sufficient sunlight for optimal results.
Transplanting
The dawn of spring, especially between early to midgestation of the season, offers prime conditions for transplanting corn speedwell. Ensure a site with moderate sunlight and well-drained soil. Gentle handling during relocation encourages flourishing growth.
III. Uses and Benefits
It is a medicinal plant.
The herb is alternative, antiscorbutic and diuretic. It has been used for the treatment of scurvy, impurities of the blood etc. It is also used as a remedy for scrofulous affections, especially of the skin, and is bruised and applied externally for healing burns and ulcers.
IV. Harvesting and Storage
If 20%-30% flowers on each spica of corn speedwell bloom, the spica can be cut off for appreciation. For the cut spica, the vase life is about 8 to 14 days. When harvesting, sharp garden shears are recommended to cut to the base of the flowering branches, and then prune the flowering branches at an angle of 45° to increase the water absorption area. Put the cut branches in a vase with clean water in time to avoid water loss.
