As pretty as they may be, some plants want all the space. They will take without negotiation. They will deprive light, food and nourishment that their neighbouring plants would enjoy so an idea to keep these containerised.
Hedera vulgaris (Common Ivy). They range from the wild to specimens like H. colchica (Sulphur heart). But by their habit they inevitably climb on other plants, wrapping their tendrils around healthy stems and eventually killing them. The Ivy will provide birds with food, invaluable nectar for many insects and adequate habitat in the winter months. Once in situ though, this plant is not slow growing. So as long as maintenance of growth control is adhered to it doesn’t pose any issue. It is only in situations where it is left and can potentially cause problems.
Hypericum calycinum (Rose of Sharon/St Johns Wort) A versatile evergreen that flowers for a longer period than most plants. In the dormant period it can be cut back for new growth to be encouraged. A yellow flower and quite attractive leaves, but it’s habit is what makes it a problem. It is low growing and effective ground cover. Very resilient and by no means delicate. It grows too quick though and spreads smothering other plants. It can survive in all conditions: dry, wet, sandy, clay, humus rich, and light – both shaded and in full sun.
Mentha suaveolens (Mint) A herb used widely. The flowers also attract beneficial insects which is clearly a attribute. It does also show mauve flowers in Summer. However, this is very fast growing. Clusters that are too big lose their scent or if differing cultivars put too close together it can happen. To benefit from the aromatics, split periodically to revitalise the plant.
Aquilegia (Colombine) a weed or not considered by some. The true plant from seed is very attractive with distinctly unique flowers. It will show for only a short period but it will appear somewhere else shortly after. Good for rockeries and areas of poor soil or no loam. Very difficult to control though. The parent plant (from seed) can often crossbreed with a common variety causing a number of mutations and self seeding hybrids forming. The change in the colour and shape of the flower is distinct. The environment they thrive in can differ too. From a meadow to the higher terrain of a mountain.
Urtica dioca (Stinging nettle) Quick spreading roots. Yellow in colour. The plant dies back in winter. This would be the ideal time to unsurface roots and dig up if not wanted. This is easier since in the height of season nettles can grow very tall and difficult to manage. Beneficial to butterflies but will smother everything if left.