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Growing Dahlias (Part 1)

Dahlias are stunners both in the garden as well as in bouquets, and are a great addition to any flower garden. Sometimes people are intimidated by them because of the tubers they grow from, and the uncertainty that goes with growing them (what to do with them in fall!?). We are here to tell you they are worth the effort, and there are ways to simplify growing them if you don't want that extra effort.

First of all, a little about Dahlias. Dahlias come in a huge variety of colours, heights, shapes, and sizes, so choosing the best Dahlia for your needs can be tricky. Some are prolific bloomers with lots of flowers all summer, some are late bloomers and in our short season may never bloom. Some have a very short vase-life, some last a week or longer (ball varieties are the longest lasting). Different varieties have many different characteristics, so don't despair if you have no luck one year... maybe it's not you, it's the Dahlia.

Dahlias like well-drained soil, and lots of air. They require a fair amount of water, but don't like to be sitting in moist soil for too long. Sitting in wet soil will cause them to rot and can cause disease, but keeping them too dry makes them susceptible to bugs, and can also lead to disease. They are best grown on sloped soil, where you can water frequently enough without the fear of too much moisture. Having them in an area with a nice breeze also help with this, and can also help to deter any bugs.

We choose not to plant our dahlias too deep. 4-6 inches below the soil gives them a good base to develop while being easier to dig out in fall than tubers planted deeper.

Dahlias grow from tubers that look like ugly little potatoes. They come in lots of weird shapes and sizes. Don't worry about how they look. Sometimes the ugliest strangest shaped tuber creates the most beautiful flower... there's got to be a life lesson in there somewhere. Each tuber must have an "eye" to be viable. This is where the new growth from your tuber will spring up, so without it your tuber will rot in the ground.

Our favourite place to purchase dahlias from is other Canadian growers. Often throughout the winter months they will have tuber sales. It's best to set an alarm for these dates because they can sell out certain varieties in minutes! Tubers aren't cheap, running from $6-$15 each (remember this is an investment that can multiply), but in our experience they are the best tubers, they typically have the best selection, and we like supporting the other growers out there. Also, purchasing from an unknown can bring a disease called Gall into your garden, and with reputable dahlia growers you won't get that. If you'd just like to try dahlias and aren't super particular about the colours or variety, a great budget option is Costco, or other box stores and garden centres. They have bags with either multiple or individual tubers at this time of year, and you can get tubers for a bargain.

We start our dahlias in our greenhouse. We simply place multiple Dahlias in a tray (a greenhouse tray with drainage) and lightly cover them with soil. We have found that because we have a short growing season here in Manitoba, this gives them a head start for the season. Once the risk of frost has passed (for us that's usually June1st) plant them out. Dahlias can take some time to "wake up" so we don't recommend watering them much at all if you're pre-sprouting them inside. You don't need a fancy set up or a greenhouse to start your dahlias. All you need is an empty salad container, a little bit of soil-less mix or potting soil, and a window! Give them a spritz of water, and you should have little green sprouts in a little bit. Since not all dahlias take the same amount of time to wake up don't be surprised if some take longer than others. As long as your soil isn't too wet (they'll rot before they start to grow if this is the case) they will sprout. Once they start growing and you can see the green shoots you can water them a little more often, but be careful not to over water!

Once they are planted in your garden, depending on the variety, you may want to stake them. Shorter bushier varieties don't need to be staked, and if you're having them just to make your garden pretty, you can sometimes leave them as well. What happens if you don't stake them is that some branches will fall over and they will get crazy shoots and stems but it doesn't actually hurt the plant. Over time it will just look like a bush and because the greenery is full you probably won't even notice. If you want to cut the flowers, staking is a necessity for long straight stems.

This should get you thinking about your dahlias and how to grow them. In future posts we will talk about pinching, disbudding, spotting "eye's", multiplying your dahlia investment, and what to do with your tubers in fall and winter, and how to do it.


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