Spring is here in Seattle, and so is dahlia-planting season.
If you are in Seattle, I highly recommend getting your tubers in the ground. They want to be there. Don’t worry about heat, moisture or any of that. They’re ready to be planted.
The ideal timeframe to plant dahlias in Seattle is between late March (which is historically our last frost) and mid-May. In previous years, I always planted them within the first two weeks of April, and usually had blooms by mid or late July.
But, if you’re like me this year, and don’t currently have the space (I’m still waiting for my beds and beds of ranunculus and anemones to bloom so I won’t be able to plant them for awhile,) then in the meantime, you need to get your tubers in the dirt.
The longer they are out of the ground, the more likely they are to shrivel or start to get squishy. (This doesn’t necessarily mean they won’t be viable, but they do want to grow so stick ‘em in the dirt.) Or, at the very least, you are delaying the window of time you have to enjoy their blooms.
Last year I had someone complain they didn’t get blooms until late October, right before the frost killed them. This person then told me they didn’t plant until late June. This is not surprising. The longer you don’t plant them, the less time you’ll have blooms. Tubers need to be in the ground for two to three months before they bloom.
Here is the behind the scenes process of how I deal with 200 tubers that I’m waiting to plant:
I must emphasize again that if you grow dahlias in Seattle, and can put them in the ground, just do it.
If you only have a handful of dahlias, and can’t stick them in the ground for a few weeks, then put them in a small pot on your windowsill you don’t need all this fancy-schmacy growing equipment.
But if you’re a crazy flower person like me, then go for it:
My dahlias are divided into two categories: Those I am taking cuttings from, and those that I am waiting to just stick in the ground. (This post is going to focus on the ones I am just waiting to plant. More on cuttings later.)
Because I know that I can’t plant for awhile, I potted up my tubers in potting soil, small containers and stuck them under grow lights. I also watered them. (I know this is a controversial statement that dahlia people on the internet will fight me over, but if you’re too afraid to water, your potting soil, when in a warm environment, will dry out, which will cause your tubers to shrivel. I’ve killed many, many dahlias this way.)
The trick with watering dahlia tubers is finding the Goldilocks method not too wet, not too dry. Once a week, I stick my finger a half an inch (or so) down and if the soil is moist or wet, I don’t water.
If it’s dry, then I water a small amount.
Since I know that my tubers won’t be staying in these pots for more than a month or so, I plant multiple tubers of the same variety in the same pot. (This is not how you traditionally plant dahlias, and I do not recommend keeping your tubers like this all season. This is my stop-gap method until I can flip my beds from spring flowers to fall flowers.)
The positives of this method:
- I know my tubers want to be in the dirt and the earlier they’re in the dirt, the earlier they will bloom.
- My tubers will start to wake up, sprout and sent out roots.
- Sometimes I have questionable looking tubers that I’m not sure are viable. By potting them up for a month before planting, I know whether or not they are duds. (I’ve had a lot of pleasant surprises over the years.)
The negatives of this method:
- I basically am planting them twice, which is twice the work. (This is why if your a regular person, unlike me, then just plant them in the ground.)
- Plus, watering and monitoring them in an extra chore. No one likes extra chores.
Which is why my advice for regular flower people (not crazy people like me) is just to plant them.