Our Complete Guide To Planting Dahlia Tubers

Last Updated on 17/03/2021 by Shannen Godwin

Dahlias are an ever-popular choice for many a summer garden. Their easy-to-grow tubers produce phenomenal displays of colour and texture in a range of styles throughout the season. However, if you’re new to gardening, you may be wondering how to plant these beauties.

Planting dahlia tubers is a straight forward process, perfect for those with less experience. With their beauty and effortless maintenance, it’s easy to see why they’re a horticultural favourite.

Why Choose Dahlias?

  1. Dahlias are easy to grow and suitable for gardeners of all skill levels. These blooms are fast-growing by nature and will flower in the first year and for many years to come (keep them stored and frost-free over the winter).
  2. Dahlia tubers 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 a firm favourite due to the many different types, sizes, and colours available on the market.
  4. New varieties are created each year. Once you’re hooked on Dahlias, you will always be able to find 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, making any display a memorable one.

Varieties

Before we move onto planting dahlia tubers, here are the main types of Dahlias. Each variety can be classified into several 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 fluffy ball.

Cactus – A favourite for many years, Cactus Dahlias produce fully double pointed petals which turn backwards to create a tubular petal effect. Are sometimes referred to as Spiky Dahlias.

Dark Leaf – As the name suggests, the foliage on this variety is not the usual bright green that you see on your average Dahlia. They create an abundance of flowers through the summer, with each bloom appearing on darker (usually purple/black) foliage.

Decorative – Produces large, fully double flowers with rounded petals through the summer right up until the first frosts. A perfect choice for cut flower displays.

Dwarf – 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 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). Another popular choice as cut flowers.

Pompom – Love the unusual? Pompom Dahlias produce ball-shaped blooms that appear through the summer. Each petal has rounded tips and are curved upwards at the edges, and are available in plenty of colours.

Planting Dahlia Tubers

All our Dahlias are supplied as top quality dormant tubers which can be planted as soon as you receive them. The success rate from these dahlia tubers is extremely high. They are also an inexpensive way to create a large number of flowers from one plant.

Dahlia tubers should 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.

Planting Dahlia tubers in Pots & Containers

Planting Dahlias in pots and containers is a fantastic way of brightening up your patios. Their unique colours and shapes will brighten any space, a perfect choice for gardens with less space to play with.

  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, leaving plenty of time to grow a well-established root 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, keeping the compost moist but not waterlogged, as the tubers will rot. Add a liquid feed weekly during the growing season and provide some protection from slugs as they have a strong love for Dahlias.
  7. If growing tall varieties, insert a cane to help with growth and to keep secure.
  8. Very little pruning is needed with Dahlias. However, you can deadhead as flowers begin to fade.

More Dahlia Tutorials

Dinner Plate Dahlias

Dwarf Gallery Dahlias

Cactus Dahlias

Bishop Dahlias

14 thoughts on “Our Complete Guide To Planting Dahlia Tubers”

  1. Really great information. Thank you.
    I use 10 inch pots for my dahlias. At the end of the growing season I put the pot and soil in the greenhouse and over-winter. In the spring I take the dried out multi compost off and repot again. I mix the multi compost with 6 month feed and water retaining gel. They thrive. Beautiful display.

  2. I’m so excited ~ this is my first year growing dahlias ~ the article is great and has filled me with confidence about producing a great show for the garden and for cutting for the house.

  3. Do you divide the clump in half, or can you separate the clump into individual tubers? I’m not even sure which way up they go!

  4. Thank you for that interesting information concerning tubers.
    I have tried to grow them but as you have stated they hate the frost..
    so in my case I lost them to both slugs and Jack frost.
    but thank once again. I will certainly try this year to get those but I have a liking for the cactus dahlia and the pompom I must take after my parents. Which is a good idea think.

    1. They really are easy to grow,but as you said Jack Frost is not there best friend.I plant into smallish pots and cover with another pot that has a hole in,A bit like forcing rubbarb.You can use black bags but must have a hole to let a little light in.I put in my green house until they have sprouted and all frost has passed.Then plant out in the garden.The point of this is to try to get them to flower earlier.You can leave them in the pots until quite big,give them a good drink before planting out,they do like to be watered.Dead head to get lots of blooms.Wary wigs like them also.

  5. could you do a video on how to do chrysanthamum’s as I adore them but have no idea on how to grow or even look after them all I can remember is that my father would leave a cane in with plastic cup on the top. The next day he would find earwigs in the cups. but that’s the old way. I believe in the copper wire. method for slugs and snails. as earwigs I think the birds eat them.

  6. Is a dahlia ‘tuber’ actually a collection of swollen roots – or can you split them up and grow each swollen root separately?

  7. Youre so cool! I dont suppose Ive read anything like this before. So good to find someone with some original ideas on this subject. realy thank you for beginning this up. this web site is something that’s wanted on the internet, somebody with just a little originality. helpful job for bringing something new to the internet!

  8. I used to have an orange dahlia with huge blooms. The ‘buds’ hung downwards until they were ready to open. Unfortunately my tubers died. Does anyone know where I can buy them again please

  9. The dahlias i purchased from you were great n can’t wait for them to come back this year, please may we have some advice on keeping cat’s from depositing in my garden, find it very unhealthy and not at all pleasant.

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