Do I need to dig up my dahlia tubers? This is an often asked question.
Honestly the answers changes depending where you live and your goals.
Where I live in western Oregon (zone 8b), I could do either because it doesn’t get too cold here over the winter. Maybe we get down to 20 degrees for a couple nights. Usually we are in the mid 30s to 40s.
Your risks for leaving them in the ground here are: they could rot if they are planted in a wet area of soil, or a critter could nibble away at it.
Another reason for digging them, besides the weather, is if you want to increase how many tubers your grow. When you dig them up, you can divide them and get between 2-8 tubers that you can replant next year! Seriously, dahlias are amazing. They just keep on giving.
If you are in the midwest or some place that is very cold in winter (zone 7 or below), you need to dig and store where your tubers don’t freeze. You do not have the option of leaving them in the ground.
When can you start digging dahlias?
Where I live, I start digging anytime after my first frost. If the plants have turned brown from frost, you can start digging. In a cold area, you need to dig before you have a hard freeze and the ground is too cold. Mid to late Oct is a good time for cold areas.
Here in Oregon, I always dig in early to mid November.
I hope this helps clear up if you should dig up your dahlias or not. I’ll be back soon to tell you how to dig and store your dahlias.