how do i get more, better blooms?
Apart from feeding and watering to keep the plants healthy there are ways of grooming the plant to control the quality and quantity of the flowers it produces.
Where several shoots are coming through the soil, select the strongest one and carefully remove the rest by cutting as close to the tuber as possible.
The first pair of leaves above the ground are the cotyledon leaves that are effectively part of the seed, not true leaves, and can be removed to improve air circulation after a few true leaves have appeared. True leaves develop throughout the plant in pairs, opposite each other, out of the main stem or a lateral/branch. Orientation of the leaf pairs alternate – if a pair is oriented east-west the next pair up will be oriented north-south.
When the plants have reached 4-5 sets of leaves pinch out the growing tip. This encourages a bushier plant with more flowers. Choosing to stop above a pair with the right orientation can ease access for the grower and reduce crowding of adjacent plants.
Branches will form on either side of the plant at the nodes of the remaining leaves. You can disbranch by removing laterals (but not the leaves) from each set of nodes to get bigger blooms on the remaining branches, to control the size and shape of the plant and to open the plant up for better air circulation. Disbranch less if you want more flowers.
As a precaution against powdery mildew strip a few lower leaves from the plants to provide more air circulation.
Flower buds develop in threes or fives – three on the ends of each branch and sometimes two more side buds at the next lower leaf pair. For show quality blooms it is necessary to disbud. Pinch out the side buds to enable the one central bud to expand into a champion bloom!
Pick, Pick, Pick
From February most dahlias will be producing prolifically. Harvest blooms and deadhead constantly to ensure that blooms maintain size and colour. Give away the excess flowers to friends, hospitals, churches etc.
Picking is best done in the morning when the plants are crisp with moisture. Immerse the stems in water immediately on cutting. If you use scissors or even your thumbnail to dig out the lateral, be sure to sterilize your tool between plants - using a weak bleach solution for example - to avoid transferring virus from plant to plant.
Members can access an excellent article on grooming to control flower production from the 2017 Summer edition of the DAHLIAS magazine here.