I have started mine off in a cold greenhouse in their final pots (large like yours. I do water them from end of February onwards and there is top growth on one already although I wish we had more sunshine to give them warmth.
Just in case you didn’t realise, @Lucy117, one dahlia per pot means the whole bunch, that has a stubby dry stem with multiple long potato-like tubers attached. Any individual tubers that break off won’t grow on their own as they need to be attached to the stem. See the photo om the recent post by Stilllearning, which may explain that better:
When you pot them up, fill your 35cm pot about two thirds full of compost, maybe a bit more depending on the pot depth, then carefully spread out the tuber, trying not to break bits off and carefully backfill with more compost, a bit at a time, gently tucking the compost in any gaps and giving the pot a bit of a shuggle to eliminate air pockets. I also find its helpful to water them when they are half covered, let it settle and the air bubbles rise, then continue topping up and water again. The tubers need to be surrounded by/in contact with the soil. Hope that makes sense and I haven’t overcomplicated it! I am fairly new to dahlia growing but find they are really easy and rewarding.
Mountainous Northern Catalunya, Spain. Hot summers, cold winters.
Hi guys.. I’ve decided to resurrect this thread as I wish to ask a few more questions about growing dahlias in pots..
I’ve recently potted up quite a lot of spring bulbs and I intend to swap them for dahlia come April/June - and repeat the cycle in late autumn when I’ll swap the dahlias for spring bulbs again. Is this a feasible plan? If I do go ahead with it should choose a potted plant rather than bare root tubers? My spring bulbs contain tulips so they won’t finish flowering till end of May.. which means the earliest I could pot up my dahlias would be around that time
Also, when you guys say ‘talk dahlias’ that are not suitable for pots, shat sort of height are you referring to? I’m a complete novice when it comes to dahlias..
I’ve tried growing in pots for 2 years now but the ones in the ground look better. Probably because I don’t water enough or feed them and they need a lot of care in pots. I’m going to stick to borders instead. Probably not what you want to hear.
Hi guys.. I’ve decided to resurrect this thread as I wish to ask a few more questions about growing dahlias in pots..
I’ve recently potted up quite a lot of spring bulbs and I intend to swap them for dahlia come April/June - and repeat the cycle in late autumn when I’ll swap the dahlias for spring bulbs again. Is this a feasible plan? If I do go ahead with it should choose a potted plant rather than bare root tubers? My spring bulbs contain tulips so they won’t finish flowering till end of May.. which means the earliest I could pot up my dahlias would be around that time
Also, when you guys say ‘talk dahlias’ that are not suitable for pots, shat sort of height are you referring to? I’m a complete novice when it comes to dahlias..
For once, I'm the right person to answer as this is exactly what I do now and after a second successful year I can say don't let the pot-negativity above put you off.
I start the tubers off in large pots inside in later winter/early spring. This lets them get a head start and there are no slug issues-
Tulips display-
I use fresh peat-free multi purpose compost for the dahlias and re-use the same compost for the tulips in Autumn since I'm treating them as an annual. Assuming you'll treat the tulips/bulbs as annuals (and don't have to wait on all the foliage dying back for a second display) then you'll be fine for timing the removal of the finished tulips with the planting of the potted dahlias. Having large pots for the dahlias allow for a mass of tulips too.
Most (but not all) of my dahlias this year-
This is only my second year of doing this so what I've learnt in that time is to not expect too much in the first year from the typically small tubers you'll buy. The below photo was taken last August (photos above are August this year) and have 4 of the same plants that appear above yet look at the size and flower difference.
The tubers will massively increase in size after the first growing season and this obviously gives them much more oomph in their second year from what I've found. See the below photos showing all the new growth (pale sections) these two tubers put on in one season-
Large pots, plenty of feeding (weekly with tomato feed) and watering once they're in strong growth and you can't go wrong. I've had to invest more money on nice, large pots etc. than I care to tally but it's worth it for a fantastic display.
Regarding heights I suspect you'll be fine with most assuming you pinch out the growing tips to encourage bushiness once the plants reach around a foot or so tall. I made the mistake of not initially staking mine this year and paid the price with some damage so won't make the same mistake next year.
I grow my dahlias in large pots (because of the slug question). It works for me. I put slow release granules in the pot at the time of planting. Yes, they need watering every other day through the summer. But I find them quite chatty - they start to noticeably droop if dry - like sunflowers. Mine get up to about 1.5 meters with no problem, but I grow in wide pots, in a sheltered garden. Balcony growing might be a bit different.
@celcius_kkw, i also grow dahlias in pots due to slug problem, though i leave those in pots over winter. So i cant help with how to time those with spring bulbs. All i can tell you is they need good support in windy location. I use a cane like support (bought some green coated canes from wilko) at the center to support main stem. I have cut the cane to smaller size than expected size of dahlia so it gets hidden. And also a conical support around it like below to support all side shoots. If i tie everything to just cane it doesn't look good. I got mine from Amazon.
Thank you all for the replies. And particularly to @Dirty Harry!
What a detailed account of your potted dahlia growing experience accompanied by such lovely photos! Thank you!
I have got a few more questions for you
1. What are the dimensions of your pot?
2. You mention you started them off in early spring - did you do that in a smaller pot and then transplant them into the final larger pot once the tulips are done? (Probably end of May?) as otherwise the spring bulbs wouldn’t have finished flowering yet in early spring..
3. Do you lift them out of the pots at the end of the flowering season (perhaps November time) and store them until early spring to be potted up again? And then use those pots for the spring bulbs?
@newbie@newbie77 Thank you for your advice on support.. i will completely avoidable placing them on the windy spots on my balcony.. I have been gardening on this balcony for two years now so I’ve actually come to appreciate all the niches well.. ie where are the most sheltered spots.. I shall reserve those spots for the dahlias.
If you don't have a garden [as in @celcius_kkw's case] or you have totally unsuitable ground, a pot is the only answer. With the right care, they're every bit as good in them. Staking/supporting them well will be vital. I have very few spots I could put them here, so would probably do them in pots again, if I grow them.
It's a place where beautiful isn't enough of a word....
I live in west central Scotland - not where that photo is...
Posts
https://forum.gardenersworld.com/discussion/1035398/dahlia-tubers-just-received#latest
When you pot them up, fill your 35cm pot about two thirds full of compost, maybe a bit more depending on the pot depth, then carefully spread out the tuber, trying not to break bits off and carefully backfill with more compost, a bit at a time, gently tucking the compost in any gaps and giving the pot a bit of a shuggle to eliminate air pockets. I also find its helpful to water them when they are half covered, let it settle and the air bubbles rise, then continue topping up and water again. The tubers need to be surrounded by/in contact with the soil. Hope that makes sense and I haven’t overcomplicated it! I am fairly new to dahlia growing but find they are really easy and rewarding.
I’ve recently potted up quite a lot of spring bulbs and I intend to swap them for dahlia come April/June - and repeat the cycle in late autumn when I’ll swap the dahlias for spring bulbs again. Is this a feasible plan? If I do go ahead with it should choose a potted plant rather than bare root tubers? My spring bulbs contain tulips so they won’t finish flowering till end of May.. which means the earliest I could pot up my dahlias would be around that time
For once, I'm the right person to answer as this is exactly what I do now and after a second successful year I can say don't let the pot-negativity above put you off.
I start the tubers off in large pots inside in later winter/early spring. This lets them get a head start and there are no slug issues-
Tulips display-
Most (but not all) of my dahlias this year-
This is only my second year of doing this so what I've learnt in that time is to not expect too much in the first year from the typically small tubers you'll buy. The below photo was taken last August (photos above are August this year) and have 4 of the same plants that appear above yet look at the size and flower difference.
The tubers will massively increase in size after the first growing season and this obviously gives them much more oomph in their second year from what I've found. See the below photos showing all the new growth (pale sections) these two tubers put on in one season-
Large pots, plenty of feeding (weekly with tomato feed) and watering once they're in strong growth and you can't go wrong. I've had to invest more money on nice, large pots etc. than I care to tally but it's worth it for a fantastic display.
Regarding heights I suspect you'll be fine with most assuming you pinch out the growing tips to encourage bushiness once the plants reach around a foot or so tall. I made the mistake of not initially staking mine this year and paid the price with some damage so won't make the same mistake next year.
Hope that's of use to you!
1. What are the dimensions of your pot?
Thank you for your advice on support.. i will completely avoidable placing them on the windy spots on my balcony.. I have been gardening on this balcony for two years now so I’ve actually come to appreciate all the niches well.. ie where are the most sheltered spots.. I shall reserve those spots for the dahlias.
Staking/supporting them well will be vital.
I have very few spots I could put them here, so would probably do them in pots again, if I grow them.
I live in west central Scotland - not where that photo is...