Dahlia Diaries Episode 4: The Big Dig.

Watch Episode 4 on Instagram here

It’s finally time for one of the biggest jobs of the dahlia calendar… digging!

It’s dirty, physical work, but it’s very satisfying unearthing what each plant has been hiding underground. I liken it to a treasure hunt.

FAQ’s:

Do I need to dig my dahlias?
No. Many NZ gardeners can leave their dahlias in the ground, especially if you have free-draining soil.

Why do you dig yours?
I dig mine so I can divide and sell tubers throughout NZ. I also like being able to inspect every clump and remove any that don’t meet my quality standards.

When do you dig?
After the plants have died back naturally or knocked by frost. Here in Gisborne, that’s usually late May to early June.

How long can tubers stay in the ground?
In many areas, all winter. The biggest risk isn’t cold, it’s rot from sitting in wet soil for long periods.

Should I wash and divide them straight away?
You can, but I prefer to store the clumps whole and divide later in winter. Freshly dug tubers are still curing and are generally more vulnerable to moisture loss and storage issues.

My tubers are shrivelling. What am I doing wrong?
Shrivelling is often caused by digging, washing or dividing too early before the tubers have fully matured. Covering tubers with fresh compost or potting mix can help reduce moisture loss during storage.

What if I find rot?
Don’t panic. It’s quite common for the original mother tuber to be soft or rotten by the end of the season because she’s spent her energy growing the plant and new tubers. Cut away any rot, allow the wound to dry, optional dust with cinnamon before placing into storage.

Why are some clumps huge and others tiny?
Variety plays a big role. Some dahlias naturally produce large, productive clumps, while others are slower to bulk up and may only produce a handful of tubers each season.

What if I accidentally stab a tuber while digging?
It happens to the best of us. Minor damage usually isn’t a problem. Let the wound dry and callous over before storage, and keep an eye on it for signs of rot.

Follow along for more Dahlia Diaries as we move onto Winter storage, trouble shooting, then eventually washing and dividing.