Exhibition dahlias are the varieties you need in order to show your dahlias. The quality that seperates them from garden varieties is primarily the petal count. They have lots more petals. This makes the flower much fuller in appearance and helps the petals to reflex right back to the stem. It helps the flower to retain its form without becoming loose and floppy. Many years of selective breeding has brought about the many different styles and forms of flower.
Many styles are fully double in their makeup which allows you to determine when the centre has become blown. ( showing the centre disc and stamens). Once a centre is blown it can no longer be put on the show bench. Time to pick for the vase inside and let new buds come away.
To grow a good bloom you first of all need to follow all the data in the garden diary.
Once you have stems with buds underway on your plant you need to think about caning stems.
This stem is called a hockey stick.
The flower will open no trouble but to see the flower you will have to lie on the floor. Not good in the vase at home or on the show bench.
This is fixable!
Stems need to be caned in the heat of the day when the stem is soft. If you do it early morning or evening when the stem is tight with water you will likely flip the bud right off.
Simply place a split bamboo cane either side of the stem, one under the bud and one at the back. Gently ease the underneath cane as high as you can to alter the angle. You might not get it all the way in one go. Take a few days to achieve 45 degrees, the optimum. It pays to make sure the underneath cane has a rounded edge so as not to damage the stem. I simply rub the cane on a stake to file the sharp edge off.
You will need to lift the canes every day to keep up with the stem growth.
Canes are also useful for stabilizing the flower on the stem in adverse conditions and when transporting to a show.
Let me take you on a pictorial journey of "Light Accord"
The stem is crooked on this plane.
The two leaves will be removed to allow the canes to contact the stem.
The two leaves removed. Side angle showing the bent neck.
Canes now in place with the angle at 45 degrees.
Clothes pegs are ideal to fix in place as they are quick and easy to shift. They must be wide opening ones. I get mine from the supermarket.
Canes are off. Stem straight and angle now good.
I normally leave canes on in order to transport.
Centre is perfect for show day tomorrow.
Where to pick?
Right down at the next set of leaves.
This gives you a very long stem to play with when vasing up. Cutting long also promotes the next flower stem to get growing.
All vased up looking pretty. The stem is now beautifully in line with the centre of the bloom.
All the effort worth it!
If your garden is too shady (less than 4-6 hrs sunshine a day) you will have plants that grow very tall, extra long and possible weaker stems. The blooms may develop white spots and there will be colour variations from the colour expected.
Too much bright sunlight especially early in the morning when dew is still around can create brown burnt spots on the petals. Too much humidity can produce brown spots on the back of the bloom too. If the sun in the middle of the day is simply fading your blooms then shade from an umbrella works wonders. It must be securely tied to a stake to prevent wind damage. If it is practicle and you can afford it a roof can be installed just prior to blooms opening. Leave the roof frame in place all year and just put the clear covering on at the last minute.
Common problems in blooms that will downgrade or disqualify them on the show bench.
A blown centre.
The central disc is visible on a double bloom. Elimination!
Bruised or damaged petals from rubbing on a stake. Downgrade.
Petaloid. If removed early will not be visible from where it came. If left then a downgrade.
Shark mouthed. Downgraded.
Try disbudding late or grow on a side bud.
Cup and saucer effect. Downgraded.
Immature bloom.
Green centres will often get better as bloom opens but if there is still green when the bloom is ready then - downgrade.
Crooked stems, bloom/stem angles more or less than 45 degrees, disproportionate stem to bloom are all faults.
Debranching
The number of blooms you let grow on a plant depends on the size of the bloom.
Debranching is the taking out of enough laterals to achieve the correct bloom size. If you left 4 sets of leaves you will have 8 laterals grow. Take laterals out in an even fashion so you don't have all laterals growing from one side.
For poms and miniatures you can let 8 - 10 laterals grow from your 4 -5 sets of leaves after stopping. The goal is to keep the size of bloom under the maximum size, so lots of blooms will help.
Smalls, 7 - 8 laterals.
Mediums, 5 laterals.
large and giants, 3-4.
Some of the newer giant varieties will cope with more than 3 blooms per plant. You can grow giants from all laterals, the terminal bud and two laterals. If you want to really get size up you can simply allow one terminal bud and no laterals. To make up numbers you simply put in more plants. They will be able to be planted closer together if you only grow one bloom.
Buds
Usually you take the two shoulder buds off leaving the centre one. This can vary for some giants that will put up better stems from a side bud. Having a variety of side buds and terminal buds can help with spreading flowering times. The opening time of buds from pea size varies. The bigger the bloom the longer it takes to come out. The range from poms to giants is from about 21 days to 33 days, approximately.
Foliage
Dahlia blooms can be shown with or without leaves. However, if you keep the leaves on then they must be in a clean and healthy condition or they will downgrade your entry. It can also be difficult to keep them out of the other stems or blooms way in a 3 bloom vase.
Sometimes there is a little leaf bract (not a full leaf) part way between the bloom and 1st set of leaves. This should be removed using a sharp knife so as not to damage the stem.
When showing poms the green bracts at the back of the bloom should be removed. This allows the tiny petals to retract all the way back to the stem forming a complete ball shape.
Too many and large leaves on your plant can be a result of too much nitrogen in your fertilzer. Once the plant is at bud stage there should be no need for further nitrogen. Potash is the main fertilizer for stems and colour. Too much fertilizer can also affect tubers ability to overwinter.
Leaves that become wrinkled and start to go grey as well as the bloom centre going brown is likely to be thrips.
Plants can have many leaves removed if fungus is a problem. This opens up the plant to air movement.
Rain
Rain can sometimes be an issue when growing the larger varieties. The problem comes from the ability of the larger blooms in particular to hold a lot of water within the petals. This makes the whole thing very heavy and if accompanied with a little wind too can cause the whole bloom to snap off. The excess moisture in the air can create very humid conditions that will brown off the back of the bloom too. The easiest solution is to erect an umbrella over the plant in question. Tie very securely to a stake, including the outer perimeter of the umbrella. Make sure it is high enough that the petals wont rub on it when it is fully open. If your finances and space allow erect a roof frame in the off season and cover with plastic just prior to blooming.
You now have your blooms looking picture perfect. How do you get them to a show without damaging them?
The main objective is to prevent petals from touching and rubbing. Keep the bloom upright, not swaying about or swivelling. It is a good idea to have stems caned to support the bloom on the stem and to help it stay in place. Canes also prevent damage to the stems.
Once at the show the only tools that I use are as pictured.
The knife for trimming stems, tweezers for pulling miscreant petals, paintbrush for cleaning fly spots etc from petals and scissors for trimming petals.
The only other things you need are a pen and lots of ripped up newspaper for packing stems in the vase so blooms don't shift when staged.
Before going to the show you need to know what classification your blooms are. A classification book is essential. These can be procured from the NZ National Dahlia Society.
Staging
Medium, large and giants are staged one to a vase.
Small, miniature and poms are 3 to a vase in the open class. Novices only need to put 1 to a vase.
Some shows will have classes for 5 to a vase.
The main criterion for blooms on the show bench.
They should be circular, even, centres closed, unblemished/ undamaged and at 45 degrees to the stem. The exception to this is Poms which are required to sit directly on top of the stem.
When multiple to a vase they should be of similar size, colour.
Stems should be straight and in proportion to the bloom.
No livestock.
I would like to acknowledge and thank all those fellow growers who have contributed to this website with their skills and advice.