Brooklime Growing, Planting, Facts & Care (Veronica beccabunga)
Veronica beccabunga is a perennial herb that is easily cultivated along the margins of a water feature. It is commonly known as brooklime, water pimpernel, horse cress, or European speedwell. This species belongs to the Plantaginaceae family of flowering plantains and is one of hundreds of medicinal species under its genus, Veronica. Many speedwells under this classification have an affinity to water, with some being highly-valued medicinal plants and others having a reputation for growing like weeds. Brooklime is a popular species in Europe and is considered a native plant in the UK. Several subspecies have become naturalized in the US.
Growing to a height of just 10 inches (25 cm) at maturity, brooklime is characterized by fleshy emergent features. Its shoots spread out from the main plant in a horizontal manner, generating ascending hollow stems that take root along the nodes of the shoot. Simple, leathery leaves arise as pairs and are distinguished by their slightly serrated edges and white veins. In late spring to summer, a flower stalk arises from each leaf axil. The blooms are quite small but are a bright powdery blue, subtly contrasting the green foliage of the plant.
Facts, Benefits & Uses of Brooklime
If your pond is located in the EU, you should definitely consider growing this marginal plant due to its many benefits. It is a native species that can successfully attract a wealth of pollinators (e.g. honeybees, butterflies, moths, and beetles) to your area. In fact, the Royal Horticultural Society has highlighted its effectiveness in their ‘Perfect for Pollinators’ plant list. The larvae of several pollinators eventually feed on the nutritious foliage.
Apart from its aesthetic value and attractiveness to potential pond visitors, its rafting stems and roots can act as a filter by stripping the pond water of excess nutrients. The canopy of leaves provides ample shade and cover for visiting amphibians, encouraging them to breed and lay their eggs in the pond.
This species has a few traditional uses as well. V. beccabunga was once used as an antiscorbutic for the treatment of scurvy. Unfortunately, the plant juice was found to lose its vitamin C content once exposed to atmospheric oxygen, rendering it a highly ineffective cure. Frequent consumption in salads may have certainly benefited its consumers, however, as it can act as a mild diuretic and laxative. Its foliage was also used as an external treatment for ulcers and burns.
Brooklime Growth, Hardiness & Climate
This plant’s species epithet, ‘beccabunga’, is derived from the German word bachbunge, which means ‘brook bunch’. This is certainly fitting as brooklime is often found growing in muddy brooks and in the oxygen-rich shores of lakes, ponds, ditches, and rivers. It prefers lotic, or flowing, freshwater systems and is quite resilient in the face of disturbance.
The creeping shoots are able to recover from dry periods and from being uprooted in storms. They act as surface runners, facilitating the spread of the plant. The shade a colony provides can prevent excess algal growth in a pond.
Hardy to USDA zones 4 – 8, brooklime thrives best in fairly cool summers. Temperatures kept close to 20˚C (68˚F) can bring out the plant’s best features. Its foliage does not require strong light exposure and can benefit from dappled shade or low light levels. Roots fare well in damp to wet soil and can be situated as deep as 6 inches (15 cm) in the marginal areas of a pond. They can grow well in a variety of pH levels as long as the sediment is composed of heavy loam or aquatic soil.
How to Plant Brooklime
Brooklime is planted using its seeds or propagated further via division. If you’ve managed to acquire seeds, they are best sown in autumn and under the protection of a cold frame or greenhouse. The germination substrate should be consistently moist. Pots placed in a tray with a few inches of standing water should work. The seedlings should be large enough to transplant in the spring of the succeeding year, during which they should be transferred into their individual pots. You may outplant them, giving each about a foot of linear space along the pond perimeter, in summer.
The best way to cultivate this creeping plant is with the use of its cuttings. Getting runners to produce new roots and shoots is remarkably easy. They readily do so upon a few days to weeks of contact with moist soil. Small cuttings with intact nodes will even produce new roots in a water propagation setup. If you have a surplus of cuttings and seeds, you can skip the cold frame/greenhouse phase of propagation. Given proper conditions, a considerable percentage of the seeds or cuttings should have no issues proliferating outdoors and maturing into healthy plants.
How to Care for Brooklime
If growing V. beccabunga around your pond, it should be situated in fine mesh aquatic baskets for ease of maintenance. This will also prevent the surface runners and roots from significantly extending the plant’s coverage area. Keep in mind that although this plant can handle full sun and is very hardy in terms of its temperature tolerances, it would be most productive in mildly cool water and under partial shade.
After flowering periods, the stems can appear bare and leggy. They may benefit from annual pruning, but this is not a requirement unless decaying or pest-compromised stems are present. Brooklime is generally pest-free but many occasionally weaken due to leaf spot, powdery mildew, downy mildew and leaf scorch (Xylella fastidiosa subsp. multiplex). If in contact with pond water, it will not require additional fertilizer. If unable to provide regular moisture, deep but infrequent watering sessions can condition the plant to survive through dry periods.
How to Winter Brooklime
Brooklime is an evergreen plant that will not need special care through winter. Its vegetative parts can tolerate temperatures that dip down to -29˚C (-20˚F). It is notably cold hardy as its leaves can stay intact and remain green even if the pond water has frozen over! As with all other frost hardy plants, simply remember to remove any dead or decaying foliage towards the end of autumn. You may trim down the plant if your area is exposed to harsh winter gales or heavy snow coverage.
Is Brooklime Invasive or Toxic?
V. beccabunga is non-toxic, but it unfortunately has the potential to become invasive outside of its native range due to its creeping habit. The surface runners tend to produce expansive clonal stands that are dense enough to mimic the effect of a raft. A brooklime raft is capable of covering streams, preventing light from penetrating into the water column. It can compete with other semi-aquatic plants for space and significantly reduce populations of native wetland species. These effects are highly localized, however, and can be managed through biological and chemical means.
In the US, colonies of its native cousin, Veronica americana, are able to stifle the spread of brooklime through interspecific competition. Pesticides have also been shown to be effective at managing spread. Though brooklime is not strictly regulated in the US, it may not be advisable to grow this plant in your area unless it has been explicitly approved.
Is Brooklime Edible? Will Fish Eat it?
The hairless leaves and stems of V. beccabunga are highly edible, albeit slightly bitter. They can be consumed raw, but are safer when cooked to prevent parasitic infection. As with wild watercress (Nasturtium officinale), to which brooklime is sometimes likened in terms of taste, the raw plant parts can contain liver fluke (Fasciola hepatica) cysts. Those that are to be consumed raw must be collected from clean areas, away from livestock or potentially polluted water systems. Once thoroughly cleansed, they can be added to salads and sandwiches. The summer flowers can be used as a garnish.
Fish may sporadically nibble on brooklime roots and shoots, which can appear to dangle in shallow water. They aren’t likely to eat considerable portions of the plant as it is very bitter. Moreover, it quickly generates new roots and shoots to compensate for any lost ones.
Where to Buy Brooklime & Seeds? (UK & US)
Veronica beccabunga can be purchased as potted individuals or bare-rooted plug plants that are ready for pondside planting. Plant nurseries and aquascaping stores located in its native range are likely to carry this species through spring and summer. Before acquiring your own speedwells, make sure they have been approved for cultivation in your area.