Dahlias are one of my favourite flowers, partly because they're so ridiculously pretty and intricate in their petals but also because they just bloom and bloom away from the beginning of summer right up until the first frosts. I've been a bit obsessed with them this summer and have had lots of requests for a post on how to grow them. They're not like regular bulbs that will just shoot after putting into the ground or perennial plants that you leave in the ground and will come back year after year. Dahlias are grown from tubers and take a bit of care at the start and end of the season but will then reward you with beauty and cut flowers all summer long and crucially into autumn when everything else starts to look a bit bare.
- You can buy dahlia plants from May/June time in garden centres but for the best results, value and choice of variety you should buy them as tubers. These will be in garden centres and available online from February/March time. They're normally sold in packets like these above or brown paper bags. You'll find that there are a huge number of varieties, shapes and colours on offer. Cactus, pom-poms, ball, stars single flower etc. Just choose what you like the look of. I tend to choose pinks, whites and peachy tones for summer flowers and then some more autumnal shades for later on. They'll flower right through to October, even November if you're lucky.
- We bought these for £1 each at a local garden centre along with having some saved tubers from last season, buying a mixed pack from Costco and buying some special varieties at Burford Garden Centre in the Cotswolds. Cafe Au Lait are my favourite. The tubers will look like that muddy tangled mess above, sometimes they'll be a lot smaller just a single piece, others will be all joined on as a big mass. At this stage they can't be planted directly into the ground as it will be too cold and damp for them so put them in a pot and cover with some compost, keep them fairly dry and not too cold. In the past we used our loft room, or even just window sills or a garage. You want the very top of the tuber to be sitting just out of the soil. If they look too dry then give a little water.
- After a few weeks, around April time they will have shot some green leaves and will have roots growing below. Keep them indoors until all risk of frost has gone and then plant into the garden around mid May time. You should have bushy plants by this time. Just dig a hole and plant them with some compost and water in. From now you can treat them as normal plants like others in the garden.
- Some people stake theirs with bamboo canes but ours tend to be quite self-supporting. You can always stake later if needed.
- Protect from slugs - they're a magnet for slugs, and earwigs if you can, and you'll have your first flowers after another couple of weeks.
- You have to keep dead heading dahlias for them to produce new buds. So either cut and bring in the house as cut flowers or just dead-head the plants regularly to keep getting new blooms.
- They will only last 3-4 days as a cut flower but by the time they're over, there should be new buds and blooms out in the garden so they're the perfect cutting garden flower. We have them in our garden and at the allotment.
- When cut the stems are hollow so you should recut them again under water so they can absorb water and last for a bit longer.
- As the winter approaches, we will dig up our favourite dahlias and keep them indoors over winter. But you can leave them in the ground and covered in mulch. If it's a very cold wet winter they may rot and not come back but sometimes they'll be ok to leave in the ground and will come back next summer - albeit a few weeks later than if you'd started them off indoors.
- My ramblings and experience are no match on Sarah Raven's advice here on her website.
Some photos from this summer's blooms -
Cafe au Lait, we've had two huge almost bushes of these and they're by far my favourite.
Peachy tones at the allotment
Cafe au Lait again, fascinates me how they change from pinky peachy hues down to creamy white.
Burgundy/Oxblood at the allotment.
Fresh pickings all summer long.
Mixed in with some David Austin roses. The frilly pom poms are fantastic.
Dahlias and downpipe in the dining room.
To match my nail varnish.
They make for pretty displays around the house.
Coral peachy summer dreams.
And finally. If you don't want to grow them, all summer long you'll find them as relatively cheap cut flowers to buy at farm shops and markets. I don't recall seeing them in supermarkets because they probably don't last long enough but at least you can find some pretty dahlia blooms if you so wish.
Let me know if you have any other questions.
R <3 xx