It is not a huge challenge to fill your garden with colour and fragrance i summer, but now that autumn is officially with us, it can be more difficult to keep the garden looking fresh and colourful. Of course, bedding plants should still be blooming but autumn-flowering shrubs are not so common. But there are some that bring colour to our gardens and they include some rather special plants that are worth adding to your plot.
Here are some of my favourites, for any size of garden.
Heptacodium miconioides
The name may be unfamiliar but this should be far more widely grown. We didn’t sell it when I was at Knights in the ’80s because it was not available. Although it was discovered in China in 1907, it did not enter cultivation in the West, firstly at the Arnold Aboretum in the USA, till 1980. If the botanical name is a bit of a mouthful, the common name is ‘seven sons flower’ because the flowers are held in groups of seven. (in fact they are in sixes but we won’t split hairs).
Heptacodium is not a shrub that make you step back in awe but it has so many good qualities that it quickly becomes a favourite. Firstly it is a large shrub, reaching 3m high and a similar width, but can be pruned to remove the lower stems, forming a small tree. The leaves are strangely curved, which makes it look distinctive and the bark peels in strips so look nice in winter. It will grow in any soil and is hardy. In my Peterborough garden it grew perfectly in light, dry soil and here, where I have planted it again in clay, that is rather wet in winter, it has also grown strongly. Although a good looking shrub all summer, it is now that it starts to perform. The ends of every shoot carry clusters of white, starry flowers. They are sweetly fragrant and butterflies adore them. They last for many weeks but as they fade the calyces, that were green when the flowers were open, change to red, providing colour until winter when the leaves drop.
If you have room, I can’t say enough about this shrub. Suffice it to say that I had one in the garden I left behind and I planted one in this garden!
Hydrangea paniculata
I answer more questions about hydrangeas than any other plant. But they are all about the hophead kinds (Hydrangea macrophylla); you know, the ones that change colour according to soil type. But Hydrangea paniculata is much easier to grow. It is hardy, will grow in any soil and reliably flowers in late summer. There are many kinds but all benefit from hard pruning in spring, just like your buddleias, and have conical flower clusters that usually start lime green, change to white and age to pink or red. Most will reach 1.5m when fully grown but some are smaller. ‘Bobo’ is a good choice for small gardens while ‘Vanilla Fraise’ (above) is a good choice, ageing to raspberry pink.
Abelia
Abelias are wonderful plants for autumn colour. There are many kinds and most are semi-evergreen, with small, shiny leaves. The older kinds reach 2m high but the more popular are variegated with colourful leaves and much smaller. Their pink flowers are slightly scented, attract pollinators and last for months.
Hibiscus
We tend to think of hibiscus as tropical flowers but Hibiscus syriacus is completely hardy and a joy at this time of year. It loves summer heat and is resistant to drought when established. It is always late coming into leaf in spring, usually not till May but is covered in blooms now. The flowers are pink, white or lavender blue and some have double blooms. I like the singles best but all are colourful, hardy and reliable.
Others to look out for are perovskia and caryopyteris, both in blue, with a loving for well-drained, sunny borders and ceratostigma, with cobalt blue flowers among leaves that change to red in autumn.
Planting tips
The ground is dry right now so watering is important when you are planting shrubs now.
Dig the hole, mix in compost or planting compost and really soak the soil. Plunge the shrub in a bucket of water for several minutes to make sure it is wet.
Plant and then water again thoroughly. This is not just to water them but also to make sure the roots are in contact with the soil.
Be prepared to water every few days until we get some decent rain to soak the soil.