Potting up dahlias

Propagation

Potting Up Dahlias

When it comes to growing dahlias in pots, it's all about picking the right variety. In this lesson, you'll learn which varieties work best.

Dahlias are tuberous plants which means they have an underground food storage system, much like potatoes do. Once planted, the tubers will continue to multiply and can be divided in the future to create new plants.

Dahlias are tender plants, so while March is a great time to plant them, they will need to be kept inside until all chance of frost has passed.

The Dahlias I'll Be Planting Are:

• Dahlia 'Waltzing Mathilda'
• Dahlia 'Molly Raven'

I'll be planting my dahlia tubers into small pots, which will then be planted in their final position in a big whopper pot in the garden once the weather is warm enough.

How to Plant Your Dahlias

Plant your dahlias into a pot that can contain the tubers but isn't much bigger than them. It is okay if the top of the stem is sticking out of the pot slightly.

This will also give you a good indication of when the tubers have started to sprout too, as you will begin to see green shoots emerging from the stem.

Planting Dahlias in a Crate

If you are planting a lot of dahlia tubers, then you might want to consider planting them in a crate instead. This will make the planting process quicker and will help you to save space.

• Line a crate with some thick plastic, such as an old compost bag.
• Pierce small holes into the bag with a pair of scissors.
• Water your dahlia tubers when you plant them, but hold off watering again until you see the first leaves starting to unfurl.
• If you are putting a mixture of varieties in one crate, make sure you label them.

Propagating Dahlias

If you want to propagate dahlias, then you need to make sure you have one individual tuber and one eyebud on each cutting. Cut this away from the main stem with a sharp knife and then plant it separately.

Peat-Free Compost

For this initial greenhouse planting, I won't use compost with lots of fertility. When they are ready to plant in their final position in a whopper pot though, I'll create a much richer planting medium by mixing the following:

• ⅓ peat-free compost
• ⅓ molehills
• ⅓ organic farmyard manure

This will help with water retention and give them the richness that they need. Store your dahlia pots or crates in a warm, bright space with good airflow until they are ready to plant out once all risk of frost has passed.