Dahlias

Would seem a good idea to me Woo as many folk seem to want to know the ins and outs of growing Dahlias. No objection from me.
Re pots or raised bed, it would depend on what size of Dahlia you are going to grow. I'd tend to go for raised bed, just because it's less to water so often! Pinching out is to stop the shoots getting too tall and makes the stems branch out more. Just like when you prune a Rose the stem then tends to produce lots of stems from where you pruned. Hope this makes sense! I sometimes do it if I remember which isn't often
Where I live I haven't a hope of leaving the tubers in the ground to over winter but my late father grew many Dahlias and living by the coast even in Scotland! where they seldom had any sort of severe frosts and he left his in the ground.He might loose the odd 1 but never that bad. That said his ground was very very free draining which is probably the key to survival.
I am NOT a Dahlia expert but have grown them for well over 20 years. 1 thing for sure is that they are gross feeders and respond like triffids to being dosed heavily with manure but in the soil and as a mulch as they like a fair amount of moisture too. No doubt others more knowledgeable than I will maybe disagree but the foregoing is what I have learnt from experience. Oh yes another thing. I start my corms off in the greenhouse. Many of my corms are massive (could split them but don't need to) and it's far too much like hard work to pot them up so I just heel then into the soil beds. Often they will have grown maybe 2ft before I'm confident of no likelihood of frost. I have lifted the corms with virtually no soil round the roots and planted them out. As long as you water/spray the leaves about 3 times a day for a few days they will transplant to bother. Down South you probably don't need to delay so long before planting out but to get flowering as early as possible and have a long flowering season this method of starting them early and transplanting when quite big works fine. One of the best things I think about Dahilas is their ability to keep flowering until the 1st proper frost. Most years mine are still flowering well into October when the vast majority of other plants have stopped doing their stuff.
I have no doubts you'll grow great Dahlias, I don't think they are nearly as tricky as some types of Roses, the only slight snag depending on which type you grow is that they do need supporting with canes etc....my pet hate!

 

Sticking would be great let me know if I should edit the original post to make it easier for people?

Everything I know about Dahlias I learnt from here. I have written a post on my blog about my challenges of growing in pots vs raised beds but I don't want to spam the forum so will type up more at the weekend on here. As silu says, it depends on the size of the Dahlia plant. The watering and feeding for me was actually no problem in pots. It was the staking because most Dahlias are huge.

My bed grown dahlias were giants but they grew far bigger than they were supposed to. They didn't look etiolated so my guess might be over feeding?


Sent from my iPhone using Tapatalk

 

I set my tubers up on 14th Feb. Most of the first shoots have been hollow stemmed, so no good for cuttings. This is nothing to worry about as its what usually happens, there will be more than enough cutting material going into April.

 

Fantastic! Do hollow stems ever root?

When you finally plant out, do you let the tubers make lots of stems or restrict it to one main stem?


Sent from my iPhone using Tapatalk

 

Hollow stems rarely root, and if they do they take ages and never make a strong plant. If you remove them above a pair of leaves, like you would for any cutting, two new shoots will soon appear from the remaining leaf axils. These are usually good for cuttings.

Because all my plants are giants and intended for a couple of shows, I will aim to stop them about the middle of June then just let three stems grow per plant. If you are just growing for a garden display or for cutting then you can allow as many stems as you like.

 

Thanks Billy, is been wondering about both of those. I can't help overthink things with Dahlias


Sent from my iPhone using Tapatalk

 

Just planted up my Cactus Dahlia collection from J Parkers . Very pleased with their price delivery and quality Hope to see some shoots in about 3 weeks . I do need to understand how Dahlia tubers work , task for this year, they have a very unique and complicated appearance.

 

That's exciting

I find the tubers more fascinating than I probably should. It's interesting seeing the little shiny buds emerging. On my ones they are appearing right in the crown around the end of the old stalks.

The only exception is one dahlia where the crown rotted and all the tubers fell away. I potted each one up and they're all sprouting the little purple shoots at the top now where they were attached, which is exciting

Having only grown Dahlias from rooted cuttings last year, I'm interested in seeing how they grow from tubers this year

 

Hi Harry, Just remember that the actual tubers, that's the swollen bits that can look a bit like a potato, are only the roots. New growth will come from the bottom of the old stem where all the tubers are joined on.

 

And also remember that the tubers are only storage organs. Unlike true bulbs ( such as Narcissi/Tulip etc ) they don't hold the embryo flowers for the next year.

This is why Dahlias can be grown from cuttings or seed to flowering In one year whereas true bulbs take a minimum of two years to flower, sometimes more.

 

Ive had reasonably good results with Dahlia tubers and cuttings down the years but have never heard of hollow stem shoots. What are the signs? Do you nip out the tip to produce side shoots for cuttings?

All info gratefully absorbed.

 

Here's one I have just salvaged from my compost bin. As you can see it is hollow down the middle, a bit like a drinking straw. It usually happens with the first shoots of the year and seems to be more common in some variety's than others. Until you actually cut the shoot off there is no real way of telling if it will be hollow or not. As I said earlier, it isn't a problem as the tuber soon produces plenty of other shoots.

 

Thanks for the info. I just wondered if there were any external signs but now I know. Thought I was maybe missing something obvious.

Thanks again.