Dahlias & Chrysanthemums
Speaker: Bryan Madders
Date: 28th April
Bryan introduced himself as Chairman of the New Forest & District Dahlia & Chrysanthemum Society.
He told us that Dahlias & Chrysanthemums are now back in fashion and can’t be beaten for late colour in the garden. The Dahlias keep flowering till the frosts come and the Chrysanths just keep on going. They come in a fantastic range of colours and forms and look great in mixed borders or lined up at the allotment.
They are easy to grow and give you a long season of blooms to enjoy in the garden and as cut flowers for the house. Bryan gave us tips for growing these stunning flowers and inspired us to try some of these stars of the late summer and autumn garden.
Chrysanthemum flowers originate from China and are of two types; early and late. Two inch long cuttings for the late flowering variety should be taken in February/March and put in a seed tray with free draining compost at once, rooting powder is optional but use CuSo4 to prevent rotting off. Label and put in a warm place to strike. Pot on when ready and cool off in the shade in a cold frame for example. Don’t over water or you will get “all bottom and no top”, a good root system is essential.
The soil should be enriched with manure and/or compost and when the plants have been planted out stake them and top dress with straw/compost. Early flowering varieties should be planted out in mid/late May. The plants should be “stopped” once only for earlies and twice if sprays are required. Nip out the central bloom and restrict side shoots to 4/5. Fewer shoots mean bigger flowers.
Pests include earwigs and green and black fly, use soapy water when first observed. Look out for brown stains and American white rust. For showing place a paper bag over the bloom and tie on tightly. Reflex blooms are popular for showing.
Singles or late flowering anemones can be grown in clay pots. Stop only twice by the end of April or early June. For the “Fairweather” family stop only once but reduce stems down to seven. Anemones can grow up to 9’ tall but a retardant can be used. Brian mentioned other varieties including “Jam tarts”, “Fantasies” from Japan with scraggy heads, Pot mums which must be grown quickly and pom poms which can be grown as perennials. Korean Chrysanths are easy to grow and flower in the late Autumn.
Brian then went on the talk about his real favourite Dahlias, these flowers originate from South America and have recently become more popular after a time in the doldrums. They like water and sunshine but don’t like frost. Slugs and snails love them as we well know! Brian mentioned the dilemma over whether to leave the tubers in the ground over winter.
There is no easy answer. If you decide not to take the risk and to dig up the tubers, the clumps should be split up every three years and over wintered in a box of vermiculite at a steady temperature of 40oF. They must be dried off first and kept dormant until planting out in February or March in a heated frame at 60/65oF with not too much water.
Cuttings rooted in March will flower in July for the whole summer. Pot the cuttings on into 5” pots and when hardened off, plant out and use a general fertilizer. Space out the plants and pinch out the top bud.
This results in a better plant with more flowers that don’t all flower at the same time. Don’t feed too much but stake and tie in securely. After the first frosts, cut back and lift and dry out the tubers, label and “put to bed”. Leave some plants to go to seed, dry off and collect seed to be sown in April.
Brian finished his very interesting and informative talk by mentioning some new varieties of dahlias which are smaller and more decorative including “Tiny Tot” plants and singles of all colours. He showed us slides of waterlily, cactus, semi cactus and pom pom classes, bi-coloured and fimbriated.