Trying to grow those dinner plate size dahlia blooms? Selection and disbudding will help you achieve your goal.
Select one of the dinnerplate dahlias like Who Dun it Dinnerplate Dahlia. This 2013 Dahlia of the Year is hardy in zones 3 to 10. Those gardening in zones 7 and colder will need to store the tuberous roots indoors for winter. These 3- to 5-feet-tall plants are loaded with flowers that transform from lilac to mauve to lavender-blue and then finish with a display of white petals.
Increase the size of these and any dahlias with a bit of disbudding. Remove side buds if you are looking for one large, knock your socks off, bloom per stem. Disbudding reduces the number of flowers, but increases their individual size.
Going for quantity? Then leave all the buds intact. You will have a lot more flowers, but they will be much smaller. Both methods create a colorful display.
A bit more information: Tall dahlias and those with large flowers need staking. Put the stake in place at planting to avoid damaging the underground tuberous root. Make sure it is anchored securely in the ground. Tie lengthening stems to the stake with a soft cloth.