Dahlias truly are the Kings of the August arrivals - they are giants in every sense.
They are greedy, for unless they are placed in rich soil, they will not prosper fully, and they also need constant watering.
Although they are perfectly hardy, you must nurture them well if you want the really spectacular displays of which they are capable.
If you want great results when growing dahlias, then you'll need to know a bit about them in the first instance.
Dahlias grown from seed, officially half-hardy perennials, are sown early and raised as half-hardy annuals to flower the same year until the frosts.
By that time they have become tubers, which should be lifted and stored carefully through the winter until Easter.
Meanwhile the seedling dahlia plants in the popular types - cactus, decorative, pompon, or the so-called dwarfs - (which reach more than 60 cm (2ft)) will grow to heights varying from 30 to 120 cm (1 - 4ft).
The taller ones should be staked for comfort, for the flowers are heavy and the stems comparatively frail.
As you probably already know, you can get them from seed for bedding displays, but it is the tubers that will give you the tall ones.
Plant them 15 cm (6in) deep and don't forget to put in a stout stake.
We can get some pretty horrible gales during their flowering period, and unless they are supported your painstaking preparatory work can be ruined in seconds.
Incidentally, if you want to cut them, the golden rule is to do it in the morning or evening, never when the sun is at its height.
You also have to be careful about lifting them.
This should be done immediately after the frost has got them, first cutting the stems down to manageable length.
There are many classifications and hundreds of varieties in commerce, far too many to name here, and new varieties appear every year almost by the score.
They are available in most colours, and study of an up-to-date catalogue is obviously the best way of making your choice.
I can, however, furnish you with a quick guide to the types and sizes, which may help in deciding where to look! Cactus and semi-cactus types have chrysanthemum-style ray florets.
Decoratives have flat flower heads with broad, overlapping petals.
Pompons or ball dahlias have globular flower heads, and Collarettes have a ring of small petals overlaying larger ones.
Large-flowered types are just that: nominally 20 - 25cm (8 - 10 in) in diameter and 1.
5m (5ft) in height.
Medium-flowered - 15 - 20 cm (6 - 8 in) and a little shorter.
Small-flowered - 10 - 15 cm (4 - 6 in) and normally not more than about 1m (3ft) tall, and Pompons - 5 - 10 cm (2 - 4 in) and also about tin (3ft) tall.
They are greedy, for unless they are placed in rich soil, they will not prosper fully, and they also need constant watering.
Although they are perfectly hardy, you must nurture them well if you want the really spectacular displays of which they are capable.
If you want great results when growing dahlias, then you'll need to know a bit about them in the first instance.
Dahlias grown from seed, officially half-hardy perennials, are sown early and raised as half-hardy annuals to flower the same year until the frosts.
By that time they have become tubers, which should be lifted and stored carefully through the winter until Easter.
Meanwhile the seedling dahlia plants in the popular types - cactus, decorative, pompon, or the so-called dwarfs - (which reach more than 60 cm (2ft)) will grow to heights varying from 30 to 120 cm (1 - 4ft).
The taller ones should be staked for comfort, for the flowers are heavy and the stems comparatively frail.
As you probably already know, you can get them from seed for bedding displays, but it is the tubers that will give you the tall ones.
Plant them 15 cm (6in) deep and don't forget to put in a stout stake.
We can get some pretty horrible gales during their flowering period, and unless they are supported your painstaking preparatory work can be ruined in seconds.
Incidentally, if you want to cut them, the golden rule is to do it in the morning or evening, never when the sun is at its height.
You also have to be careful about lifting them.
This should be done immediately after the frost has got them, first cutting the stems down to manageable length.
There are many classifications and hundreds of varieties in commerce, far too many to name here, and new varieties appear every year almost by the score.
They are available in most colours, and study of an up-to-date catalogue is obviously the best way of making your choice.
I can, however, furnish you with a quick guide to the types and sizes, which may help in deciding where to look! Cactus and semi-cactus types have chrysanthemum-style ray florets.
Decoratives have flat flower heads with broad, overlapping petals.
Pompons or ball dahlias have globular flower heads, and Collarettes have a ring of small petals overlaying larger ones.
Large-flowered types are just that: nominally 20 - 25cm (8 - 10 in) in diameter and 1.
5m (5ft) in height.
Medium-flowered - 15 - 20 cm (6 - 8 in) and a little shorter.
Small-flowered - 10 - 15 cm (4 - 6 in) and normally not more than about 1m (3ft) tall, and Pompons - 5 - 10 cm (2 - 4 in) and also about tin (3ft) tall.
Source...