I fell in love with dahlias a few years ago after covering the annual tuber auction held by the Greater Pittsburgh Dahlia Society at the Munhall Borough building in April. Here's the column.
They are just one of the tender bulbs or tubers I grow in my garden and I want to save them year after year. For many gardeners, that's a real pain, they don't want to be bothered and I always tell them, just let them freeze and start again next season.
But I'm too cheap for that, my parents grew up in the Great Depression in the 1930's and taught me to be frugal. My friends might say they went overboard as I'm routinely accused of being tight, cheap, penny pinching, stingy and my favorite, a tight wad. I can't help it, but at least I recognize that I'm cheap.
So here's how the guys at the dahlia society taught me to save my tubers each year. When the foliage is blackened by frost, cut the dahlia foliage down. Cover the hollow stalk with aluminum foil to stop water from getting to the tuber. The tuber stays in the ground for a couple of weeks, still growing. This promotes eye formation. When the clump is dug and split, each division needs at least one eye to produce flowers the next year. I dig the tubers out, and let them dry for a couple of days in my sun porch on cardboard. Split them and mark every tuber with a magic marker. I use a Sharpie to actually mark the variety on the tuber itself. They all look the same next spring, so good labeling is important.
I like to use vermiculite as a storage medium, but like anything gardening, there are lots of other ways gardeners do this. I start with a five-gallon bucket of it and add one cup of water. To tell if it's moist enough, grab a handful and squeeze. It will feel moist, but not dripping. To be sure that it's not too wet, shake your hand and the vermiculite should fall apart. I fill a box with a couple of inches of the moist vermiculite, and then lay the tubers in so they are not touching. Then a couple more inches of the medium and so on and so on until the box is filled. It's stored in a cool frost-free place that ranges from 45 to 50 degrees. Check the tubers twice during the winter for rot. Pull any rotted tubers out and send them to the compost bin.
It's really easier than it sounds, you'll get a good feel for it quickly.
I store my glads, caladiums, cannas and begonia bulbs the same way. Instead of cutting the glads or cannas, dig them out and use the same technique as for the dahlias.
Dahlias multiply each season, so next spring, offer your extras to friends. Then they will be hooked like the rest of us.
Keep an eye on this blog in April and join me at the annual auction, it's one of the wonderful gardening events in Pittsburgh and something you should see at least once.