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Dahlia

Dahlias can be responsible for some of the biggest and most spectacular blooms within your garden! With such a large selection of sizes, styles, and amazing colours there will surely be something that you fall in love with! Our range of well-established, ready-to-plant Dahlias can be used in borders or containers and offer a fantastic flowering time from Summer through to Autumn. Dahlias are one of the easier plants to care for, especially because we do the hard bit! By the time we deliver them direct to your door, they are already established and garden ready. Once there is no more frost forecast, find a nice, sheltered spot with plenty of sunshine for your Dahlia to thrive.

How to prolong the flowering period.

Once the plant has reached about 20cm tall, pinching out the main growing tip to encourage more flowering side shoots. Use a sharp knife or your thumb and forefinger to remove the main shoot (in the centre of the plant, growing upright) down to the top pair of leaves

Tie in the new growth to the stake weekly if possible

Feeding your dahlias with tomato feed, maybe once a fortnight to encourage the flowers to keep coming

When it comes to dahlias, deadheading is the most important task to prolong flowering. Ensure you are removing the spent flower heads and not the new buds, the easiest way to tell is that the buds are more rounded, whereas the spent flower heads are more pointed at the tip. Be sure to remove the whole flowering stem.

 

What to do with Dahlias over the Winter.

Overwintering in the ground

If you prefer a low maintenance approach to wintering your dahlias, this option may be for you. With recent winters getting milder, it is possible to leave your dahlias in the ground over winter. To do this, you must wait until the Dahlias have become blackened by the first autumn frosts. Then you will need to cut them back to around 10cm off the ground. The next step is to make sure they are deeply mulched to protect them from the frost.  (don’t be shy, the more protection the better). If you have multiple dahlias next to each other in a border, it may be wise to label each one as you are cutting them back, so when it comes to spring you know where you are.

If the winter is kind, your dahlias should re-appear in spring, often before the potted plants. Then you will know that you are in for that fantastic display of colour for another year.

Please be aware, that if you do take this option and there is a cold winter, the risk of losing your dahlias completely becomes a strong possibility.

Overwintering by lifting

A much more reliable, all be in time consuming way to ensure your dahlias are protection over the winter months, is to lift them out of the ground and store them under cover. We would certainly advise using this method if the dahlias are planted in a mixed border. If they are mixed with plants that have a strong growth in the spring and the winter, this will cause the dahlias to become over shadowed.

To do this, wait until the autumn frost have blackened the tops, remove all surplus soil including the loose soil around the tuber and cut them down to roughly 15cm and remove them from the ground.

With the time of year, it wouldn’t be sensible to clean the tubers off under a tap. Simply place the tubers upside down or a tray or a crate for a few weeks, allowing them to dry out. Once they are dry, pack them away in a try or a storage box. Ensure that the tubers are surrounded with dry sand or compost or even wrap them in newspaper to stop them from drying out.

Store them in a cool, place that will not get frosted, an attic or a shed will be fine. Make sure that you regularly inspect the tubers throughout winter to ensure there is no rotting.

 

Troubleshooting with Foliage and Flowers

Leaves and Flowers with irregular holes and pieces eaten away with slime trails present on or near plants = It is likely to be Slugs and Snails, I would say place some Broken eggshells around the bottom of the plant

Leaves with white dust like covering = Powdery Mildew can be treated with a fungal spray from your local garden centre

Leaves, shoots and flowers infested by colonies of black, green or yellow wingless and winged insects; Foliage sticky and sometimes sooty = Aphids or a bug killer spray from your local garden centre

Leaves with irregular holes and pieces eaten away; no slime trails present on or near plants = Caterpillars

Flowers with holes (centre of bloom) and petals with pieces eaten away no slime trails present on or near flower = Caterpillars, remove them from the plant and place them somewhere far away.

Flowers with tattered petals = Earwigs this is simple to fix, Spread petroleum jelly around the stems of your plants

Dahlias tend to do well in most sunny locations, with and fertile soil moisture and decent drainage.

 

Planting in the Garden

Pick the perfect spot for your Dahlia, dig a hole wide and deep enough to easily accommodate the size of the root ball. It helps to add a little compost to the bottom of the hole and if you are located somewhere that has heavy clay, ensure you add some grit or stones for drainage.

For taller Dahlias, it may be an idea to add a stout stake just before you plant out. This way you can place the Dahlia next to the stake, allowing you to tie the Dahlia in when necessary as it gets taller

 

Planting in Containers

You want to select a container that is at least 30-35cm in diameter and depth. It’s important to use good quality (peat-free if possible) compost and when there is a dry patch in terms of the weather, you may need to water your Dahlias every day, they are quite hungry plants. Again, make sure to add the stake so you can tie them up later.

 

Types of Dahlia

Single-flowered have a central disc surrounded by a single ring of rounded or pointed florets that can sometimes overlap.

Anemone-flowered can have one or multiple outer rings of flattened ray florets surrounded by a dense centre of tubular florets.

Collarette dahlias are easily recognisable by a single outer ring of overlapping flat ray florets and an inner ring of smaller florets before a centred disc.

Waterlily are double, with wide range of florets giving a shallow saucer shape.

Decorative dahlias have double blooms, the broad ray flowers curling inwards.

Ball dahlias have double blooms forming a mildly flattened ball shape and where the rounded or blunt ray florets are arranged spirally and involute on themselves.

Pompom flowers are even larger than balls, double and spherical, made up completely of florets that curve inwards.

Cactus dahlias have double blooms with pointed flowers, straight or incurved and rolled over.

Semi-cactus flowers are wider than the cactus type, but still are double and with extremely pointed flower tips.

Fimbriated dahlias have ray florets that are split evenly or notched into two or more divisions equally throughout the bloom and creating a fringed effect.

Star dahlias have a single outer ring of uniformly involute or revolute florets surrounding a disc.

Double orchid dahlias are fully double. They do not have a disk and boast triangular centres. Ray florets may be involute or revolute.

Paeony types have large flowers with 3 or 4 rows of different flattened rays surrounding a central golden disc

History of the Dahlia

The Dahlia originates from North America, mainly from Mexico, however species can be found in other countries such as Honduras and Costa Rica. It has been in Europe now for over 200 years, making its way from Mexico to Madrid.

As far as we know the named species that were imported into Europe were; Dahlia Rosea, Dahlia coccinea and Dahlia pinnata. It wasn’t long before horticulturalists in Europe worked out that Dahlias were a natural hybrid and when growing from seed, it frequently changed its colour and form. That is why today we have such a huge range of dahlia that most if not all people can find one that they love.

During the mid 1800 the first double flowered cultivars were developed and called, Show and Fancy types. Shoe were self-coloured, with ball like flowers and fancy types were multicoloured. Today there are cultivators in the form of the paeony, the waterllly, the chrysanthemum, the anemone and the orchid.

Today there is nearly every colour and colour combination to choose from (except blue), there are dahlias that offer massive blooms on tall 1m+ stems or small types such as lilliput or topmix. The evolution of Dahlias continues as people desperately try to create a true blue dahlia, a dahlia that has a scent and also a frost hardy dahlia that will last through the winter.