Dahlia Classification
Dahlias originally came to us from Central America, but they have been bred throughout the world and there are now thousands of varieties in countless colors and combinations. To make it easier to know what type of dahlia you are looking at or to find a particular dahlia, a classification system has been developed, grouping them by form, size and color. To be honest, I don't think it makes it much easier for the average gardener, since the classifications have sub-classes, the terminology is not always clear and new developments bring changes to the categories.
To enter your dahlia blooms in flower shows, you will need to know exactly what type you are growing. If you are growing them for your own enjoyment, classes only matter if you are looking for a specific type of dahlia.
Very generally, you can categorize dahlias as either single flowering or double.
Single flowering dahlia classes include:
Most larger flowering dahlias are doubles and they are further classified by the diameter of the fully opened flowers. These designations actually are useful to the average gardener, because they give you an idea of what to expect from the tubers you order.
From there, it gets even trickier, with subclassifications for petal shape and color. I will have to defer to the experts here, because even if I could explain it all to you, new developments can mean yet more changes in classification. If you would like to learn more. I would suggest starting with the American Dahlia Society.
Even if they are sold as annuals, they will form tubers that can be stored and over-wintered. They don't tend to get any taller than
The biggest recent break though in dahlias is the introduction of shorter dahlias with the flowers and blooming capabilities of the larger classes. They bloom profusely all season, but remain compact, growing between 8 - 24 in. tall.
One series in particular, to keep an eye on, is the Gallery Series. These grow 12 - 20 in. with all the glamor or fully double blooms. They are named for painters. Like 'Rembrandt', 'Monet' and 'Pablo'. I'm sure there will be more developments to come.
More Reading
To enter your dahlia blooms in flower shows, you will need to know exactly what type you are growing. If you are growing them for your own enjoyment, classes only matter if you are looking for a specific type of dahlia.
Very generally, you can categorize dahlias as either single flowering or double.
Single Flowering Dahlias
The single flowering types have petals in circular rows around a visible central disk, much like a daisy. Flower sizes don't tend to get any larger than 4 in. and the plants grow to about 3 ft. or less.Single flowering dahlia classes include:
- Collerette Dahlia
- Peony Flowers Dahlias
- Single Flowered Dahlias
- Star Dahlias (formerly known as Single Orchid Dahlias)
Double Flowering Dahlias
Double flowering dahlias have multiple, overlapping layers of petals with no visible center disk. Shapes, petal arrangements and petal forms vary greatly. Flowers can be round pompoms, convex or wildly spiky. Classifications that are double flowering include:- Anemone Flowers Dahlias
- Ball Dahlias
- Cactus Dahlias (and Semi-Cactus)
- Decorative Dahlias (Formal and Informal)
- Double Orchid Dahlias
- Pompom Dahlias
- Star Dahlias
- Waterlily Dahlias
- Miscellaneous Dahlias
Most larger flowering dahlias are doubles and they are further classified by the diameter of the fully opened flowers. These designations actually are useful to the average gardener, because they give you an idea of what to expect from the tubers you order.
- AA (Giant) Larger than 10 in.
- A (Large) 8 - 10 in.
- B (Medium) 6 - 8 in.
- BB (Small) 4 - 6 in.
- M (Miniature) less than 4 in.
From there, it gets even trickier, with subclassifications for petal shape and color. I will have to defer to the experts here, because even if I could explain it all to you, new developments can mean yet more changes in classification. If you would like to learn more. I would suggest starting with the American Dahlia Society.
Dwarf, Miniature and Bedding Dahlias
There are a few dahlias that remain relatively small in height. They are not always labeled as dwarf or miniature, but you may find them sold as annual bedding plants, because they do not need staking, topping out at 24 in. or less.Even if they are sold as annuals, they will form tubers that can be stored and over-wintered. They don't tend to get any taller than
The biggest recent break though in dahlias is the introduction of shorter dahlias with the flowers and blooming capabilities of the larger classes. They bloom profusely all season, but remain compact, growing between 8 - 24 in. tall.
One series in particular, to keep an eye on, is the Gallery Series. These grow 12 - 20 in. with all the glamor or fully double blooms. They are named for painters. Like 'Rembrandt', 'Monet' and 'Pablo'. I'm sure there will be more developments to come.
More Reading
