So, You Want To Grow
GIANT DECORATIVES IN SCOTLAND?

HAVE you ever visited a flower show and stood in awe, amazed and impressed by the size and beauty of giant decorative dahlias and wondered to yourself How do they grow them like that?’

Well that was me on my first visit to the National Dahlia Society’s Northern Show at Harrogate during the late 80’s. 1 had never seen giant dahlias grown and exhibited to that standard, and was convinced that growers in Scotland could not grow to, or compete at that level.

However since then, having grown nothing other than giant decoratives and about a dozen giant semi-cactus I am now beginning to understand their needs and requirements, to achieve reasonable results. But it is not until you actually grow them that you can fully get acquainted with them.

Let me say at the outset, that growing giant decoratives is not difficult in any technical terms, but what is required is hard work, a willingness to spend as much time as possible on the plot and attention to detail.

Before embarking on an assault on these heavyweights, some form of targets and pre-planning must be considered and one or two questions answered.
a] What are my targets and ambitions?
b] What and how many varieties to grow?
c] How many plants can I grow and look after properly?

If you just fancy growing a couple of plants to produce a bloom or two for a local show then half a dozen plants would suffice. If I could only grow one variety of giant decorative, that variety would be the yellow coloured Wanda’s Capella. It may not be the most classical of the giants, but it is easy to grow early to flower and makes decent size and formation.

Do your ambitions aspire to exhibiting in the giant decorative championship class at the Scottish National? This class requires six blooms at least three distinct varieties I would recommend that consideration should be given to growing six different varieties and at least eight to ten plants of each variety.

I can already hear you say, why grow so many of each variety if only two or three blooms are required, and yes with luck an entry could be made with less plants and varieties, but that is leaving a lot to chance or luck. Bear in mind that most giants must be grown three up to help achieve a good sized bloom. Timing is also very important when growing giants - no run on methods or second flush blooms. Also blooms of giant decoratives only remain in peak condition for a very short period of time A bloom may be perfect two days before a show, but by show day, it could be past its best, whilst the next bloom on that plant may be too young or immature to be suitable.

To have any real chance of success on the show bench at any given date, it is obvious that the more plants of a particular variety that can be grown, the greater the chance of having blooms available on that day. Conversely I would not consider growing any more than fifteen plants of any one variety, as this can result in unnecessary wastage.

By the time we look at the London show which requires twelve blooms, all different varieties, then a large number of plants is required.

My own personal ambitions at the start of each season is to grow for and compete in the three national Shows at London, Stirling and Harrogate, together with entering several local shows. I grow ten plants of each of my Banker varieties together with seven or eight plants of another ten varieties and three to four plants of any new or untried varieties. Include twelve plants of Daleko and Pink Jupiter [G.S.C.] and in total I grow somewhere in the region of two hundred and forty plants.

No matter whether you intend to grow just six plants or five hundred plants, you will want to achieve the best blooms possible and the following applies equally to both types of grower.

Good Stock
It is vital that good stock is initially acquired. If you do not know an exhibitor who could start you away with a tuber or a few cuttings, then RIDGEVIEW NURSERY, CROSSROADS BY LONGRIDGE, BATHGATE, WEST LOTHIAN, EH47 9AB, SCOTLAND. Telephone 01501 771144 have one of the best selections of giant decorative dahlias in the United Kingdom.

Planting Out
Two weeks before planting, a top dressing is applied. In the past I have used Vitax Q4 or more recently fish, blood and bone at approximately three to four ounces to the square yard. Have some sort of planting chart made out and have the canes in situ in good time.

Remember to give giants as much space as possible. In an area where I once grew 180 plants [various classifications] I now grow 120 giants each approximately 30 to 36 inches apart. Apply slug pellets before planting as young plants are vulnerable at this time. Avoid unnecessary checks such as frost, pot bound plants and root rot [erratic watering] as plants that receive a check at this time never fully recover or produce outstanding blooms.

Timing of giants is paramount and because of the cooler growing conditions, it takes much longer for a bloom to fully develop in Scotland than it would in the south east of Englandshire As such, late flowering varieties must be stopped in mid May. The majority of varieties I stop as they are planted and the early flowering varieties during mid June.

This is the only time during the summer months that I would contemplate taking a holiday, when the plants are left to their own devices after having received a good watering

Summer tasks
Into the first week in July and by this time it actually looks as if the plants are beginning to grow. At this time the number of breaks on each plant is stripped down. Usually one break is selected near to the top of the plant, one in the middle and one near to the base. The higher the break the earlier it will bloom. Any basal breaks often produce the largest blooms.

Some people advocate leaving six or seven breaks on and only when the buds are in sight are the breaks selected, but I believe in getting the three breaks secured as soon as possible to allow the growing energies to be concentrated in the three breaks helping to produce as big a bud as possible. Big buds will mostly always produce large blooms.

After the breaks are selected I apply a mulch. A three and a half tonne trailer load does about 120 plants and this little operation is carried out at the start of the Glasgow fair holidays. Only after the breaks are secured and the mulch applied do I start the watering and feeding programme This is when the first ties are made using the three stake triangular method. Plants are never tied direct to the main stake, as the stem could be damaged at a later date. Instead twine is wound around the three canes, holding the plant in place.

Watering and Feeding
Having to work continental shifts and irregular hours, causes the feeding and watering times to be a bit erratic, but is usually over an eight to twelve day period.

Liquid feed is given usually in the form of Miracle-gro or other balanced feed Watering is much more important than feeding and during a dry spell I will try to
water twice weekly, especially just before bud formation I can leave the hose running unattended for one hour between each double row of twelve plants whilst continuing with other work on the plot.

Disbudding
In this part of the country it can take 35 to 40 days for a small bud just secured to develop into a full bloom although this timing can vary if extremes of weather are experienced Bearing in mind that the first National Show last year was the 8th September at London the diary was highlighted between the 29th July to the 4th August as the main disbud dates [41 - 35 days] to London. Some buds were taken before these dates and flowered earlier, only one variety namely Amaran Relish was fully budded up before these dates and this proved to flower too early [mid August].

It is at this time of year that as much time as possible should be spent on the plot. With no children and no other hobbies only the job and the wife are distractions. If possible I try to be on the plot at some stage every day, the only exception I make is a Saturday night which is reserved for eating out, drinking and socialising. Even the football takes second stage at the start of the season.

Balanced liquid feeds continue until the buds start to show colour, then a granular feed of rose fertiliser is applied which is said to improve colour and stem. At this time the police issue torch comes in useful in the nightly search for that lover of the dahlia the Earwig, although for some reason this is not a major problem for me. However caterpillars have taken refuge in my plot over the past couple of years and cause just as much damage. Spraying on a fortnightly basis with either Sybol or Tumblebug is the extent of my protection programme. However, when the buds reach full colour stage the spraying stops and a powder application of Sybol is given to the foliage [One Sassenach thought I had treated my plants like babies and had even applied talcum powder to them].

Covering
Covering is a must, although last year it remained dry until Grangemouth Show which is at the end of September. I also erect netting as side protection to prevent buffeting It is also important that blooms do not touch each other and are pulled and tied away from the canes to prevent petal damage About one week before the first major show the plants receive a final heavy watering. At this time the lower foliage of each plant is also removed [usually on my hands and knees]. The combination of foliage removal and watering is designed to assist the mulch dry out and allow better air circulation all of which helps prevent damping off or marking of the petals. It also removes any hiding place for insects and with all excess side shoots debranched to try to obtain maximum size in the blooms.

Where possible, blooms are cut 24 hours before judging and placed in deep water. All stems are pierced under water to prevent air locks and bubbles emanating from the pierced area indicates that water will be taken up without air locks causing problems. There is nothing worse than a cracking bloom shattering because it failed to take up water. Only three blooms secured by twist ties to each five gallon drum and left in a cool dark garage. Whilst staging try to spend some time on each bloom, using small brushes to remove as much dirt and insects as possible. Any damaged or eaten petals at the back should not be removed until as late as possible.

When staging multi bloom exhibits it is desirable to present a balanced exhibit to the judges. On three tier staging the largest bloom or blooms held at 90 degree angle should be at the back and the smaller bloom or blooms which sit on top of the stem should be on the bottom tier.

Giants tend to be staged one to each vase and showing them low in the vase creates the impression that the bloom is large although short stems and a lack of foliage has been criticised by others (who don’t even grow giants].

Varieties to grow in order of preference

Bonaventure. Massive at three up. Grow 4/5 up for multi bloom-work.

Alva's Supreme/Cream Alva's. Excellent formation but prone to shatter without warning.

White Alva's. Identical to parent but one I find grows slightly smaller.

Wanda's Capella. Easy to grow and flowers early.

Amaran Relish. A personal favourite but does not always produce good blooms, some centres not round.

Mark Hardwick. Yellow reflex form which flowers later than usual in my area.

Mabel Ann. Excellent on its maiden year, not so good last year with some streaky petals.

Kidds/Almand Climax. Low growers, beautiful colours and formation.

Lula Pattie. White, must stop mid May.

Zorro. Red, not a classic, I persevered with this one.

Gemma Darling. White with hint of pink flush. Deep blooms which mark easily in damp weather.

My Pride. Another late variety good formation.

Go American. Old variety - useful for multi-bloom exhibits.

Sam Huston. Good formation and colour but not widely grown.

Hamari Gold. A favourite in England but not with me.

Bill Holmberg. Excellent colour and early but no depth.

Walter Hardisty/Arthur's Delight. Two white varieties, both late flowerers, will not grow either again.

Creve Coeur. Massive red but lacks class and formation.

GO ON! Try them and have a go, you won’t be disappointed.