Page 59 - Simply Vegetables Spring 2023

East Yorkshire District Association
Our October 2022 Meeting, which featured Ian Sutherland (four-time National Dahlia Champion) from Blackburn talking about Dahlias, attracted a record-breaking and wide- ranging audience of nearly 70 people and the venue almost ran out of chairs to seat everyone! Amongst the new faces who attended, we welcomed Bradford- based Andrew Cunningham – Chair of neighbouring West Yorkshire DA and Dorothy Wilkins – Chair of Hunmanby & District Garden Produce Association.
Ian took us through his growing cycle beginning with tuber storage and preparing them ahead of cutting formation, removal and on-growing. Any tubers that show signs of leafy gall formation (caused by a specific bacterial infection) should be disposed of
as affected tubers will never produce show quality blooms. He aims to propagate 3500 plants of which he keeps about 600 for his own use, donating or selling on the rest to help defray expenses. His growing benches are constructed using a polystyrene base insulating layer covered by an electric heat mat, pond vinyl sheeting, capillary matting and a fleece coat covering over the tubers which helps to increase the air temperature by up to 5 deg C above ambient. He believes bottom heating of 16 – 18 deg C to be most important, especially during the colder months of January and February when he aims to initiate the
growth of new buds.
Using the above rooting cell method, Ian expects to transplant his rooted cuttings into 7cm pots after about 8-12 days towards the end of April. The young plants are further transplanted into 9cm pots for 2-3 weeks before planting out at 45 – 60cm (18”-24′′) intervals into his final growing beds at the end of May/beginning of June. The beds are professionally-analysed for soil nutrients beforehand but typically receive a top dressing of 84gms/ m2
(3 oz/sq yd) EX4 (or equivalent general fertiliser), 84gms/m2 (3 oz/sq yd) calcified seaweed, 28gms/m2 (1 oz/sq yd) nitro chalk and a scattering of chicken manure pellets which is all raked in about two weeks before planting. His growing beds are then covered with Mypex membrane sheeting which greatly reduces the need for weeding.
Some dahlia varieties will grow in the open but, for exhibition and show work, some form of protective covering is required. Even a simple umbrella can be used to keep the rain off individual plants! Apart from wind damage, the weight of heavy rain can cause petals to split which will render the blooms useless for show purposes.
Once planted out into their final growing positions the plants receive no further feeding for the first month. Thereafter
and up to bud formation stage, Ian uses
high nitrogen liquid feed
at a rate of about 2 pints per plant, supplemented
by foliar feeding with
liquid seaweed. After bud formation, high potash feed at the same rate is used instead, supplemented with foliar feed and Epsom salts. Apparently, he does not use any potash feeds on his Kiwi varieties and little or no phosphate fertiliser
is applied to any of his plants at all. He has found that overfeeding tends to produce coarse blooms and increases the chances of tubers rotting whilst overwintering.
The three main dahlia pests to watch out for are red spider mite, western flower thrip and capsid/mirid bugs. Most of the really effective chemicals are now only available to purchase as a licensed user but some degree of protection is afforded by off-the- shelf products such as Provanto, KillerMite, Bug Clear and Decis.
According to the National Dahlia Society, there are 14 recognised classification groups of dahlia although Ian says that most serious exhibitors focus on Groups
5, 6, 7, 8 and 9 only. His own particular
favourites are Kenora Challenger, White Moonlight, Kiwi Gloria (does not like growing in the open though), Barbarry Surprise, Barbarry d’Amour, Skelmersdale Jayne, Blyton Red Ace and Blyton Softer Gleam. Of the single-flowering varieties which are more suited to general garden growing, he highlighted Sunshine, Tally Ho, Roxy and Bishop of Llandaff as being some of the best varieties available.
Overall, it was a very entertaining and informative presentation from someone who clearly knows how to grow and show dahlias at the highest level. However, there were plenty of tips available for even the casual grower and exhibitor to learn from and apply in their own garden.
Our November meeting (and last meeting of 2022) featured Peter Rogers – Assistant Estate Manager at Burnby Hall. With the aid of PowerPoint, he gave us a presentation covering the four seasons at Burnby Hall, a popular attraction located in Pocklington, East Yorkshire.
He started with a brief history of the
Hall and the development of the lakes (originally built for fishing parties) and the rock garden. The lakes are now home to a national collection of water lilies numbering some 100 varieties and also stock impressive numbers of roach, Rudd and carp, as well as some resident herons.
Autumn provides vibrant colours
(the deciduous redwood is particularly impressive) as well as the opportunity to repair pathways and to trim hedges. It is also time to plant the spring-flowering bulbs; 18000 tulips comprising 130 varieties are planned for 2023. Autumn also enables the following year’s programme of visitor events to be planned and promoted.
Winter snowfall is rather rare and the reduced vegetation cover enables the various sculptures within the grounds, such
Ian starts to take cuttings
in March, but April and May
usually produce the best
cuttings which are softer
and root more easily. Ian
has a large greenhouse
which is equipped with a
Hotbox Sulfume sulphur
vaporiser to reduce the
risk of fungal diseases and
pest damage. He aims for
a cutting size of about 5cm (2′′) in length and cut just below a leaf node which encourages rooting. If the leaves on the cuttings appear disproportionately large, he will trim them down as this will reduce water loss through transpiration, prevent wilting and allow uninterrupted root growth. He also uses rooting stimulants such as Chryzopon Rose and Chryzotop Green. His rooting cell growing mixture is a 60/20/20 proportion of Clover Professional compost/ grit/ perlite. For the casual dahlia grower, smaller quantities of cuttings can simply be rooted in small pots sited on a warm, well-lit windowsill and enclosed in
a plastic bag to maintain suitable humidity levels.
Even a simple umbrella can be used to keep the rain off individual plants!
Ian Sutherland – four-time National Dahlia Champion
Simply Vegetables 59