JANUARY in the garden
Happy New Year!
If this year is anything like 2023 there will be lots of rain and humidity which means we are in fungal territory. So in between showers keep up with the baking soda!
The other issue that will affect your dahlias is straight heat. Consistently hot temps will stress your plants and can cause a major reduction in growth. Plants will simply not grow to size, they will not put up as many blooms, sometimes none at all. Last year my giants, those that grew a bud were not only stunted but 60% or so never flowered. No amount of watering will counteract the high temps.
Dahlias under stress will also shorten the internodal length. This is quite tricky for debranching and good stems. The plant will appear quite dwarfed.
If your problem is heat and dry, then keep up with the watering first thing in the morning, particularly if the plant is still droopy from heat of the day previous. Do not turn on irrigation hoses in the heat of the day especially if they are black. You will cook your tubers with hot water.
Continual rain may also wash away a lot of the good fertiliser that you have put down. If stems are spindly and not holding the bloom up well, then add a dash of potash around the plant.
To Do List
Spray – fungal and bug.
Stop the central stem to allow laterals to grow.
Debranch as many laterals as you need to achieve good bloom size. The bigger the bloom is supposed to be the less blooms should be allowed to grow.
Disbud. Remove the shoulder buds leaving only the central bud. If you want a really long stem then take out the laterals from the next set of leaves down. Some giants do better by growing on the side bud, but that is for later on in your skills journey.
Stopping is the term for pinching out the central leader on the plant. Dahlias usually grow to a central leader and produce one terminal flower. To grow many flowers people allow lots of shoots to come away. However, the tuber will do better by only allowing one shoot and stopping the terminal leader. If you stop at 4 sets of leaves after you have removed lower leaves for airflow, then the plant will grow all the laterals and so produce 8 terminal flowers.
Debranching is taking out specific laterals in order to allow bigger bloom size. The bigger the blooms, the less flowers should be grown.
Disbudding is removing the side buds and only allowing the central bud to grow. This will encourage longer stems, better flower size and less damage to petals. To get even longer stems then you can remove the laterals from the next set of leaves down.
For the home gardener this is all you have to do. Keep up with spray and dead head when the bloom has blown its centre. A blown centre is when the centre of the bloom opens up and exposes the stamens. Some varieties look quite aesthetic at this stage but the flower is entering its reproductive phase and takes more energy from the plant to do this. By taking the flower off it will encourage new ones to develop. Keep deadheading right throughout the season.
If you are not fussy about your stems then you dont need to do anything. Most of us though like to have straight stems and the bloom at a good angle to the stem. More information on this in the exhibition section!
Fully blown centre
Hockey stick stem
Picking Is best done early in the morning when there is plenty of water in the stem and bloom. Take a bucket to the garden and cut your stem down to the 2nd set of leaves. You can trim shorter if needed but you cant add extra. Place immediately in deep, cold water directly into the bucket. Large stems with big hollow sections benefit from having a knife inserted at the lowest node and twisted to let the air out, underwater. No further intervention is needed to prolong vase life. Maintain fresh water in your vase and do not put in direct sun or too hot a position. Smaller balls and decoratives last a little longer than their large and giant cousins. The flower will continue to open once in the vase. The good thing about dahlias is they dont have to have a l-o-n-g vase life as there is always lots more in the garden to replace them.