Amazing results can be achieved by using textural elements of plants, either through the leaves or flowers. Usually perennials will give your border that extra zing when coupled with contrasting plants or as a cluster of the specimen.
Echinops bannaticulus (blue globe thistle) these flower in summer and are best planted in a cluster. The flowering period can be prolonged by cutting off dead heads. On the whole, very low maintenance but have a tendency to disperse in wind. These seeds can easily germinate where their not wanted so another reason to cut flowers heads off when spent.
Another Echinops is ritro ‘veitch ‘s blue’ – this flowers in late summer and again the same rules apply. The specimen tolerates all soils as long as it is free draining. You can propagate these by division.
Monarda, or ‘Bergamot’ as it is commonly known possess strikingly attractive flowers. In summer, it offers an architectural element in any mixed border and its crimson colour is distinctive especially in a cluster grouped with any contrasting foliage.
Monarda didyma is commonly used for its crimson red effect although there are pink and purple varieties.
Eryngium bourgatii (Sea holly) runs throughout summer and offers architectural value in a perennial border up until autumn. It survives in poor soil as long as it has light and is sheltered to an extent. It also prefers to be in free draining soil and will not sit in waterlogged loam.
Eryngium planum offers summer flowers and is particularly good in clusters. Needs to be in full sun. Eryngium can have quite long roots. When they are settled avoid root disturbance as they don’t like being moved.
Stachys byzantina ‘Silver Carpet’ is a perfect foliage plant that provides effective mat forming clumps or low growing ground cover at the front of any perennial border. Very hardy. Stachys does lose its leaves eventually in winter ready for its spring growth. Survives in sandy soil and can withstand drought conditions.
Hosta undulata ‘ Mediovariegata’ is another choice for effective foliage at the front of a mixed border. The variegated leaves are clump forming and provide effective colour – they prefer slight shade and an acidic more humus rich environment. If the soil is too alkaline the leaves will suffer chlorosis. It is also a good idea to place them in a slightly sheltered spot as they don’t tolerate particularly cold winds.
A relatively recent addition to the foliage selection is Senecio ‘Angel Wings’ it has proven to be very successful despite only being cultivated in the last couple of years. Clump forming and generally maintenance free it offers all year round colour. It does bear yellow flowers in summer although that’s not what it known for. Needs a more humus rich than sandy soil. However, it will not tolerate being wet so must be free draining but have some substance. It likes the sun and will thrive in these conditions. It is good at sustaining its vigour with harsh cold winds but if the temperature really drops well below 0, it is a good idea to relocate or protect from the elements.