Potting up dahlias

Potting up Dahlias

Potting up your dahlias in early spring and keeping them undercover gives them a head start and a better chance of a magnificent display all through the summer. In this lesson, Arthur talks you through exactly how to do this, avoiding common mistakes and pitfalls.

Dahlias can be potted up in the early spring to get them growing before the last frost. You'll need to put them somewhere with plenty of light but safe from frost, like a windowsill, a cloche, or a greenhouse if you have one.

If you're planning to grow a lot of dahlias, it's worth doing a decoupage listing the varieties to help remind you what to order and plant when.

Plant your decorative dahlias earlier than the singles. This is because huge flowers with lots of petals need more time and energy to produce all those petals.

Creating the Right Conditions

Dahlia tubers can't handle too much cold and wet weather or they'll rot. So when we pot them up, we're trying to give them just enough moisture and warmth to get them going.

Larger dahlias will need to be potted up in 3-litre pots, while smaller varieties could go in smaller 2-litre pots. A combination of molehill soil, organic manure, and peat-free compost will help the dahlias establish strong growth. The crown of the tuber should be only a centimetre or so under the top of the compost, where it's nice and warm and will encourage the dahlia to wake up.

They shouldn't need feeding until they're planted out in the garden, ready for the summer show. And remember to label your dahlias, especially if you've potted up quite a few.