All Hail the Queen
May is possibly the busiest month for gardeners in the Northern Hemisphere! Starting late season seeds, dealing with the endless amount of mowing, pulling weeds, planting out, mulching - the list goes on and on.
And chief among them all, for any flower gardener especially, is getting the queen of the garden - your dahlias - situated.
Dahlias are native to the highlands of Mexico and Central America, where they were cultivated by the Aztecs for their edible tubers and ornamental beauty. They were introduced to Europe in the late 18th century, quickly becoming popular for their vibrant colors and diverse forms. They prefer warmer temperatures, but they will stop blooming if it gets too hot for too long.
Dahlias are winter hardy as long as they are in a spot that is well draining and does not freeze. Obviously that takes Maine right out of the equation unless they can be kept in a minimally heated greenhouse where the soil around them doesn’t freeze. In Mount Vernon, we stay warm enough… sometimes. This year, we spent a week in the single digits and my dahlias had been planted relatively shallowly which meant they’d need a lot of mulch in order to protect them from the temps we reached. Suffice it to say, I’m starting with almost 100% new dahlia tubers this year and a handful of the ones I was able to get out of the ground in time.
Planting and replanting tubers are the only way to ensure you get the exact same variety of dahlia from year to year, but new hybrids are being developed through specific pollination of seeds by some amazing breeders. If you save seeds from your dahlias (a very fun thing to do), you won’t get the same variety, but you will get a whole collection of genetic combinations of flower parent and pollen parent and maybe a new variety you’d like to try out by saving the tuber in the autumn! We’ll talk about digging and harvest at the end of the season (with an on-farm workshop opportunity for those of you in the area), so for now, let’s just talk about planting.
Planting Instructions
dig a hole about 6 inches deep.
place your tuber horizontally rather than vertically.
cover your tuber with soil and press down so there is good soil contact.
do not water.
keep an eye out for voles or moles or critters that might dig it up and eat it for lunch.
when you see foliage (could be days, could be weeks. be patient.), begin watering. if you water before that, you risk rotting the tuber before it has a chance to set any roots to absorb all of it.
when it grows 6 or so leaf sets, pinch it by cutting right above a leaf node, leaving two full leaf sets below the cut.
stake each individual plant or if you are planting multiple, corral them with stakes and twine to protect them from heavy wind or rain weight that might cause them to topple.
harvest flowers by cutting as deep as possible. we’ll go over deep cuts later in the season and I’ll demonstrate. If you are letting your flowers bloom on the plant, regularly dead-head your plant to keep it blooming until the killing frost.
A few other tips:
You can plant your tubers as close to 6 inches together if you’re short on space. They don’t need all of the legroom that is usually afforded them. If you do this, you’ll want to strip the foliage from the lower part as the plant gets larger in order to increase airflow and discourage powdery mildew.
Each variety grows at its own speed. For example, Peaches N Cream will always be one of the first, Cafe au Lait will always be one of the last. They were born that way.
Once they get established, they do love water, so you’ll need to make sure they’re getting a fair amount of water a couple of times a week. I alternate between drip irrigation at their root and an overhead sprinkler because I find that they thrive when they get real rain so I try to simulate that if it’s missing.
They love a good foliar feed with a fish or kelp fertilizer until they start to flower. After that, I’d probably switch to a rose fertilizer for them if anything at all.
They are deer and bunny magnets so make sure you have some protective measures in place if you’re close to any of those friends.
Dahlias don’t continue to open once they have been harvested so you’ll want to let them open up entirely on the plant before you harvest for a vase or bouquet.
Leave your questions in the comments and I’ll answer them as I can!
