Dahlia types and sizes
The classification of dahlias is a simple system based on type of petal shape, size and formation of the bloom.
Sizing
Pompon – diameter not to exceed 50mm.
Micro – not to exceed 60mm.
Lge pompon– 51mm -80mm.
Miniature – not to exceed 115mm.
Small – 115mm-155mm.
Medium – 155mm – 200mm.
Large – 200mm -250mm.
Giant – Over 250mm.
These are official sizing classifications as published by the National Dahlia Society of NZ.
(The term “dinnerplate” is a generic term that doesn't denote any particular size except that it is largish.)
Bloom & Forms
Ball Dahlias
The tip of the petal has a rounded end. Petals reflex well back towards the stem. Usually come in
miniature and small sizing.
Semi Cactus Dahlias
The base of the petal is flattened and the tip is semi revolute.
Size -Min-Giants
Cactus Dahlias.
Petal is revolute( rolled back on itself) from base to tip.
Size -Min-Giants
Decorative Dahlias.
Petals are more pointed than the balls and curved forward.
Size -Min-Giants
Fimbriated Dahlias
Petal shape of decorative or semi cactus but with split tips.
Size -Min – giants
Collarette
Flat, single row of petals with an inside collar of petals.
Waterlilly
Resembles a waterlilly with a flat back.
Pompones
Spherical in shape. Petals reflex right back to te stem.
Single
Flat, single row of petals, usually 8.
Ball, Decorative, Semi Cactus, Cactus, Fimbriated should ideally have a depth from front to back that is 2/3 the front diameter.
Flat shaped blooms include; Collarette & Waterlilly.
There are many other types of dahlia but this is a selection of the most common types.