Dahlias in their full glory! Now is the time to plant the tubers

Mar 8, 2019 - POSTED BY Monique Halloran - Gardeners Choice

Dahlias give a wonderful burst of colour in your garden borders from mid-Summer through to the first frosts in late Autumn.  They are also easy to grow!  The colour range is huge as are the flower heads themselves, so they definitely make a statement in your garden.  I often design the planting border to have Poppies and Dahlias planted together in the same cluster.  Poppies flower first and as they die back you can cut them right down just as the Dahlias are starting to grow and take their place.  This is called layered planting and works really well in small gardens. 



Personally I prefer to buy my Dahlias ‘in the green’, as small plants.  This is the easiest way to be sure they will take in your borders and is done in early Summer.  However if you have the ability and love to garden, the cheapest way is to plant your Dahlia tubers now, in early Spring, indoors.  When the shoots are about an inch tall, divide the tubers into several parts and pot up each section of the plant separately, into small pots, to grow them on inside.  Obviously it is important to ensure each new ‘plant’ has both roots and shoots to ensure healthy growth!


Once the Dahlias have been planted in your herbaceous borders, then keep an eye out for the time they start to grow taller and will need to be staked. Dahlias have such lovely large flowers their heavy heads can blow about and break the stems if they are not supported. The flowers last for ages if cut for flower arranging, and indeed they last for a long time in the garden too. Each plant can have up to 10 flowering stems, though if you reduce the flowering stems, the remaining flowers will grow larger.  It is quite nice to play with this and have some where you remove at least half the flowering stems, so encouraging huge flower heads, and some which are full of slightly smaller flowers. 

For those of us that  live in the South of England, it is possible to simply leave your Dahlias in the ground to over Winter, perhaps protecting them with some bark chips around the roots.  If your soil is heavy and claylike though, or you live in the colder regions of the UK, then follow the RHS advice and lift out the plants from the soil, dry them off,trim off any fine roots and place the plants in an open tray in peat free soil or sand just leaving the crowns exposed, to over winter them indoors.  I hope you enjoy a wonderful, colourful Dahlia display this Summer and Autumn!