Complete Guide: How To Plant Dahlia Tubers

Dahlias are an essential choice for the summer garden. The easy-to-grow tubers will produce a phenomenal display of colour in a range of styles with beautiful dense foliage. Dahlia work perfectly with almost all types of plants, and complement any garden wonderfully regardless of size.

Whether you’re looking to add some vibrancy to your summer, decorate your patio with impressive pot/container displays or grow a ready supply of cut flowers – Dahlias can do it all.

Background

Dahlias are native to Mexico, and the country’s national flower. The Aztecs grew Dahlia tubers as a food crop, and they were widely used there for their nutritional and medicinal properties long before being propagated for their beauty.

It wasn’t until 1789 when the plants were sent to Abbe Antonio José Cavanilles, Director of the Royal Gardens of Madrid, that they got the name we know them by today. Named after the famous 18th Century botanist Anders Dahl, Dahlias were then developed and cultivated to the wide selection of hybrids and varieties we have today – with 42 different species.

Why Choose Dahlias?

  1. They are easy to grow, and suitable for gardeners of all skill levels. They are fast growing by their nature and will flower in the first year and for many years to come (just keep them stored and frost free over the winter).
  2. They are versatile and will tolerate most types of well drained, fertile soil or compost. They can be grown successfully in pots, tubs, window boxes and in borders.
  3. They are one of our favourite summer bulbs because of the many different types/sizes/colours available, which all look slightly different in shape, but are all equal in beauty.
  4. Year after year sees many new exciting new varieties introduced which means once hooked on Dahlias, you will continually be able to find and try something new.
  5. They flower continuously through the summer, right up until the first frost of the autumn.
  6. They look fantastic as cut flowers and are great for lovers of something a little different.

Varieties

The main types of Dahlias available can be classified into a number of different categories, representing the main characteristics of the flower blooms themselves.

Anemone Flowering – Also known as Powder Puff Dahlias, these beauties produce unique flowers with double feathered central petals resembling a Powder Puff.

Cactus – A favourite for many years, Cactus Dahlias produce fully double pointed petals which turn backwards to create a tubular petal effect. Sometimes referred to as Spiky Dahlias, they are perfect for the border.

Dark Leaf – These Dahlias are a little different in that their foliage is not the usual green colours of most varieties. They create an abundance of flowers through the summer as expected, however the blooms appear on darker (usually purple/black) foliage.

Decorative – The largest range of large, fully double flowers with rounded petals through the summer right up until the first frosts. They produce masses of flowers for cutting purposes.

Dwarf Gallery – A range of smaller, more petite Dahlias which are perfect for the front of the border. They are prolific flowering varieties, look also great planted mixed together in pots on the patio.

Dinner Plate – As the name suggests these are the largest flowers within the range, often up to as much as 25cm in diameter (see illustration below). Try these as cut flowers and be certain to draw attention.

Pompom – Love the unusual, then these are certainly for you. Almost spherical flowers (like balls) appear through the summer. The petals have rounded tips and are curved upwards at the edges. The flower heads are also slightly flattened towards the centre.

Dahlia Tubers

All our Dahlias are supplied as top quality dormant tubers which can be planted straight into the place where they are bloom (their final location). Success rate from these dahlia tubers is extremely high and they are a relatively inexpensive way to create a large number of flowers from one tuber.

Dahlia tubers can be planted 10cm deep in fertile well drained soil, outdoors in spring when the frost has disappeared. They prefer to be in a sunny location and spaced at approximately 45cm apart. In areas where there is extreme cold, dig up dahlias and store in a cool peat over the winter. Apply a high potash fertiliser every few weeks in the summer to help growth and they can be dead headed when necessary.

How to grow Dahlia plants in pots or containers

A fantastic way to brighten up your patio is to introduce some Dahlias in pots/containers. The colour range is fantastic, with many unusual bi-colour varieties which will brighten up any space. Simply beautiful to sit back and look at during a warm summer afternoon.

  1. Once your tubers arrive safely in the post, they can be soaked overnight in a bucket of water to soak up as much moisture as possible.
  2. When all signs of frost have passed they are ready to pot up, giving plenty of time to get well established before the summer.
  3. It is recommended to place some pebbles at the bottom of the pots before adding the compost to help with drainage, by ensuring the compost doesn’t block the drainage holes.
  4. Fill in some compost and then add the tuber with the growing tip facing upwards.
  5. Continue to fill in the rest of the compost to firmly hold the tuber, making sure the growing tip at the top is peeping out and is not completely covered. This is now ready to be moved to the patio or garden area, with access to as much sun as possible.
  6. Water well after potting and then keep compost moist but not waterlogged as tubers will rot. You can add a liquid feed weekly during the growing season and provide some protection from slugs as they really love Dahlias.
  7. If growing tall varieties, insert a cane to help with growth and to keep secure.
  8. Little pruning is needed on Dahlias, however you can deadhead as flowers begin to fade.

More Dahlia Tutorials

Dwarf Gallery Dahlias

Cactus Dahlias

Bishop Dahlias