Dahlia Plant

...choice number 1 - The Dahlia - a bit late in the season , but hey blame ciao for the time it took to get the subject listed .

Brief History :

The Dahlia family originate from Mexico , and were first introduced into Europe ( actually the Botanical Gardens of Madrid , Spain ) towards the end of the eighteenth century , with three species introduced namely Dahia pinnata , Dahlia rosea and Dahlia coccinea .
The ...
...illustrations and descriptions of the dahlia .
Initially the said three dahlia's were grown in Europe as the only known / recognised species . However it was not long before Dahlias were grown from seed , from which variations in both form and colour were noted , and thus it was realised that the Dahlia was in fact a natural hybrid.

Species :

There are thirty-five known different species of Dahlia , which are ... more

I love to potter around in the garden . While not a novice by any means , I am no Alan Titmarsh , but for the benefit of the Ciao brigade , I thought I would complete a few reviews on my favourite garden plants.....so here goes with choice number 1 - The Dahlia - a bit late in the season , but hey blame ciao for the time it took to get the subject listed .

Brief History :

The Dahlia family originate from Mexico , and were first introduced into Europe ( actually the Botanical Gardens of Madrid , Spain ) towards the end of the eighteenth century , with three species introduced namely Dahia pinnata , Dahlia rosea and Dahlia coccinea .
The name Dahlia was given to the plant in honour of a Swedish scientist turned enviromentalist by the name of Andreas Dahl , by botanist Abbe Caranille , whose authorative work " Icones et Descriptiones Planatarum " ( 1791 , updated 1795 ) , provide some of the earliest known illustrations and descriptions of the dahlia .
Initially the said three dahlia's were grown in Europe as the only known / recognised species . However it was not long before Dahlias were grown from seed , from which variations in both form and colour were noted , and thus it was realised that the Dahlia was in fact a natural hybrid.

Species :

There are thirty-five known different species of Dahlia , which are sub divided into eleven groups . From these groups you then find hundreds of hybrids , providing you with a wealth of choice.

Groups :

As I previously said , the thirty-five species have been split into eleven groups . The groups are as follows :

1) Single flower - a single ring of florets ( petals ) with centre forming disc.
2) Anemone - one or more flat outer rings , with tubular / conic florets within but no disc.
3) Collerette - single flat outer ring , with a ring of inner florets in the centre that form a disc.
4) Waterlily - double blooms made up of rings of broad flat florets . Depth of these is usually less than half the diameter .
5) De corative - double blooms whoose florets are broad and flat . The ends f hese florets can either be slightly upturned or slightly twisted to provide a point.
6) Ball - a double bloom , with florets shaped to produce a ball .
7) Pompon - a looser much larger variation of the ball dahlia .
8) Cactus - Again double blooms - this time the florets are mainly narrow and all are pointed . Florets will be a mixture of straight and incurved to produce a thistle effect .
9) Semi-cactus - differing form the cactus variety by having broad based florets that narrow to a point . Other characteristics are the same.
10) Miscellaneous - those that do not fit into a one particular group.
11) Fimbriated - usually cactus or semi cactus type but can be found in other groups - these consists of dahlias whose florets split into two or more divisions at their ends to produce a ragged whispy flower head.

Groups 4 , 5 , 8 and 9 are further sub-divided into size of flower head .

Colours :

Dahlias come in a huge colour spectrum , of which there are 11 groups , namely :

1) White
2) Yellow
3) Orange
4) Bronze
5) Flame
6) Red / dark red
7) Pink
8) Lilac / lavender / mauve
9) Purple / wine / violet
10) Blends ( two of more colours that merge into one new combined colour
11) Bi-colour / variegated ( mainly a single colour , but florets will be striped , splashed or tipped with another colour ) .

Groups 1-9 inclusive are further divided into individual colour variations , for example there are four variations of white .

Relatives :

Belonging to the same family we also find the widely known Waterlily , Anemone , Chrysanthenum , Aster and Daisy .

So as you can see the Dahlia range is simply huge . Whist choosing an individual sub species may be almost impossible , growers do make things simple for the average gardener by providing a good choice of various size plants in a good choice of colours.
Such plants can be used in mixed beds, dedicated displays and herbaceous borders .
It is however not the above that are my main reason for prefering Dahlia's over any other types of flower , for Dahlias are very easy to grow . They do prefer a well drained rich soil , but will flourish in all sorts of climate and soil condition .
You will usually pruchase Dahlias in one of two forms - pre-grown plant or tuber - the latter are my preferred choice as you actually get to see then grow from the very beginning .

Planting :

The traditional time for planting Dahlias is late Spring ( UK - late May - Mid June ) - the actual time is dependant on weather conditions , ie possibility of frost . Before planting the use of a fertiliser such as blood fish and bone ( added to the soil ) will aid growth , but is not required . Should the ground be dry , watering in the plant / tuber is required , however if soil is moist it is best left alone to encourage the roots to seek water on their own .

Caring for :

Dahlias do require a lot of watering , but do not tolerate standing water . During the flowering season try to keep weeds to a minimum thus reducing the fight for water . At the start of the growing process tuber roots delve quite deep into the ground in search of water . Near to flowering stage the tuber roots spread along just under the surface to further aid water collection .
An unfortunate characteristic for all Dahlias is the fact that black / green fly are attracted to it ( especially during the first growth spurts ) , and will require the use of pestiside to control ( although a washingup liquid / water solution can aid in reducing infestation ) . Young plants are also a loved target for slugs and snails , so precautions need to be taken here as well .
Dependant on type of Dahlia grown , you may require the use of stakes or netting to secure your plants .
In the UK , mid to late July is when Dahlia's usually first begin to flower . At the first stage , the main growing point should be removed ( yes you are taking off a flower head ) . This however encourages the growth of side shoots , which will result in a greater flower display . For those who require earlier flowering , removal of the main flowering shoot should be made in mid-late June . It is however entirely up to the gardener wether he/she removes this first growth . Plants will still produce a good display without its removal .
Dead-heading of flagging flower heads is required as this will encourage new flowers to develop .Flowering will continue upto the first frost , and it is not unknown for flowers to be present in late November .

Dahlias are not frost hardy , and the first hard frost will turn leaves black and signal the end of the flowering season . This is the time that tubers are usually removed from the soil and stored for future years . If your area is not prone to very heavy frosts it is possible to leave your tubers in the ground all year round . However a heavy frost will kill the tubers - remedies do exist to protect tubers left in the ground eg. a bed of straw placed over the tubers during winter.
Tubers left in situ should however be lifted every three to five years and the tubers split to control population and size .

Tubers should be lifted once the first heavy frost has arrived . Foliage should be cut back and the tubers removed from the ground and the surface moisture alowed to dry out. Tubers can then be placed in peat or vermiculite and stored in cold greenhouse or cold frame until the following year . Care should be taken not to allow frost to penetrate them or them them to totally dry out .

So why do I like Dahlias ? Well they last for many years , come in a huge range of shape , size and colour , are easy to care for being very undemanding wih respect soil conditions temperatures and sun provision . Furthe r more , they make excellent cut flowers

Finally two facts that may interest you .... a true blue coloured variety is still sought , flower head sizes range from minute ( 25mm ) to huge ( 12" ) in diameter  

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