Plant of the week
Achilleas are useful and colourful plants in the summer garden. There are many different achilleas but the most popular are the coloured forms of the common yarrow (Achillea millefolium). These grow to about 60cm high, have flowers in shades from orange, cream, pink and red and suit lots of garden styles.
Why grow it?
These achilleas form spreading clumps of ferny leaves in shades of green to grey and have flat heads of small flowers that last many weeks. They attract pollinators and they make good cut flowers too. There is a wide range of colours to suit all tastes and colour schemes. The plants are hardy and tolerate a wide range of conditions and are drought tolerant when established. They can be used at the front of deep borders and around roses. You can buy them now for instant colour.
Where to grow it
Achilleas need full sun. They will become floppy and need staking if planted in shade. Light, sandy soils are perfect and they will grow in clay soils too provided they are not waterlogged in winter. They can be grown in pots but they are not ideal – if you do, plant in John Innes compost and keep them watered.
Where to start
You can buy named varieties all year round in pots but they are best planted in spring or summer. Keep plants added to the border in summer well watered till they are established. Another option is to grow from seed. Mixes such as ‘Summer Berries’ are great value and if sown in early spring they will bloom the same year. Even better, sow now and the young plants can be settled in in September to bloom next year.
What to do
After flowering, cut the plants back so they make some new basal foliage and to prevent seeding. This may also encourage a second flush of flowers. If seeds are allowed to form these provide seeds for birds but the achilleas may seed into lawns. In windy sites the flower stems may need some support. Push a few twigs into the clumps as they start to grow to provide support.
Plants form a woody base and can be divided every year or two in spring.
Who will like this?
If you like a natural effect and want to encourage pollinators you will like achilleas. They create a mass of colour and are good as cut flowers.
Plant them with …
Hardy geraniums, sedums, lavender and agapanthus
Jobs for the week
Dahlias
Keep plants growing and flowering. Give a weekly liquid feed to boost growth. Deadhead regularly or cut the flowers for the house. Put earwig traps among the plants to prevent them damaging the flowers. (Put an upturned pot, stuffed with straw or paper, on canes among the plants and empty them each morning)
Hydrangeas
It is too late to apply hydrangea colourant to change the flower colour to blue but you should still feed hydrangeas, especially plants in pots. They are thirsty so water frequently and apply a general liquid fertiliser every week until September. You can take tip cuttings of young shoots.
Beans
Broad beans will have finished cropping and can be pulled up. Keep picking runner beans and French beans as the pods are ready. Keep them watered while the flowers and pods form to ensure a good crop.
Strawberries
When all the fruits have been picked you can cut off the old foliage and give the plants a good soak and a feed to encourage healthy new growth. If you don’t need more plants cut off the runners too. But if you want new plants, peg the runners into the soil where the plants are forming so they root.