When you can’t rely on the weather to keep you warm there are some plants that will bring plenty of heat to your garden. Among these, the two genera I rely on are crocosmias and kniphofias, both African plants.
Crocosmias are often known as montbretias and they are familiar plants. They are generally easy to grow though they have a reputation (only partly deserved) for being slightly frost tender. They certainly thrive in mild areas of the country and where there is plenty of rainfall. In the west of the country, south west Scotland and Ireland montbretia is often considered an invasive plant but this really only applies to Crocosmia crocosmiiflora, commonly called montbretia after the Napoleon’s botanist Coquebert de Montbret.
The hybrid was created by Victor Lemoine in 1881, the man who brought us so many great garden plants like philadelphus and lilacs, by crossing two wild species. After that breeding achievement new crocosmias were bred in many countries, including here, especially in Norfolk, and recent years have seen lots of new ones introduced.
But the most popular of all, bred and introduced by Blooms of Norfolk, is ‘Lucifer’. It is tall and stately, searing red and a glorious sight in July, at the start of the crocosmia season. Crocosmias vary in their growth habit and some are ‘runners’ and quickly form large expanses, like the common montbretia, but others form neat clumps and fortunately ‘Lucifer’ is generally well-behaved in the garden and forms clumps.
Crocosmias grow from corms and a new one is formed above the old one every year so if you dig up a clump you will find ‘necklaces’ of old corms in the soil.
You can buy dried corms to plant in spring but it is best to buy growing plants because the dried corms can take a while to get growing. Now is the perfect time to add some to your garden, seeing the plant in bloom at Nags Hall.
Although crocosmias like sun, they will also grow in part shade, though they may flop a bit. They also need plenty of moisture. They may be African but they naturally grow in grass and long streams so they will not thrive in dust dry soil. A good, fertile soil is best but they will even grow in clay provided it is not waterlogged in winter. If you need to divide clumps this is best done in spring.
Crocosmias are upright and their grassy, pleated foliage is bold and attractive even before the flowers. They are useful to add colour in borders and they are perfect to buy and pop in the border now for instant colour. With colours ranging from bright reds to orange and yellow, there is lots of potential for bold colour combinations.
The other African plants that set the garden alight in summer are the kniphofias. Commonly called red hot pokers, these vibrant plants were popular in Victorian times but have been a bit out of fashion for too long. Luckily, some recent breeding work has developed smaller and better varieties including the American ‘Popsicle’ range that are colourful and packed with flowers.
They need a sunny spot and well-drained soil but are also unphased by clay. Their flowers drip nectar, which is important in the wild where they are pollinated by birds but in the garden they are visited by bees and wasps.
Not all are fiery shades and there are more subtle colours if you need something cooler. They are not bulbs but herbaceous perennials with dense, thick roots and they can be hard work to lift and divide. They are generally free from pests but snails love to overwinter in the clumps of dense foliage, especially the older, bigger kinds.
Weekly reminders
Deadhead dahlias as the flowers fade to encourage more flowers
Feed pots and baskets every week to keep them growing and to encourage more flowers
Be sure to water camellias and rhododendrons in pots. It is now that the flower buds start to develop and drought now will lead to lack of blooms next spring.
Look out for autumn-flowering bulbs such as nerines and colchicums for sale and plant as soon as possible
Cut hedges