If you grow flowers for cutting, you simply MUST grow dahlias. Dahlias are some of the easiest and most rewarding flowers to grow in your cut flower garden. With blooms in every color and ranging in size from huge dinner-plate flowers the size of your head to perfectly round pompom dahlias, there is a dahlia for every taste.
Dahlias take anywhere from 90-120 days to produce flowers. With a frost free growing season of just 140 days this does NOT leave much time for my dahlias to pump out blooms. Since I lift my own dahlias and store them over winter, however, I can pot my dahlias up in late February and start the growing season 10 weeks early. This insures in an blooms up to 2 months earlier and longer than if I waited on dahlias from an online provider.
Late Fall: Prepping Your Dahlias to be Over-Wintered:
If you garden in areas where the ground freezes in the winter, like we do in Boulder, you'll have to pull your dahlias out of the ground. The benefit of this extra step is you can split your dahlias and quickly multiply your stock. On average, I triple my dahlias with every splitting but some plants can offer up to five new plants at splitting! Given how expensive these tubers are initially, even doubling your stock makes the effort of splitting them well worth while!
Every fall, after a few frosts have blackened the foliage but the ground has yet to freeze solid, use a pitchfork to lift your dahlias from the ground.
I group the dahlias by type and wrap them in burlap (you can use brown paper as well or place them in sand in a crate). Store your wrapped dahlias in an area that stays between 32 and 45 degrees. For me, this means storing them in my garage along an interior wall. If you live in an excessively dry climate (like Colorado) it can be helpful to sprits the wrapped dahlias once a month or so so that they do not fully dry out and shrivel up.
Early Spring: Splitting Your Dahlias
In early spring or late winter bring your dahlias out of storage. For me this is usually done in late February. Ideally you will have a warm day on which you can accomplish this outside. This year, unfortunately, we've been hit with a two week long cold snap so I was forced to do my splitting inside. I simply put a large plastic bucket in the kitchen sink and resigned myself to some extra dirt clean up.
Unwrap your bundles and shake any excess dirt from the tubers. Your tubers may have shriveled slightly or they may appear totally plump. If they are significantly shriveled you can try soaking the tubers in luke warm