another dahlia question!!

Sorry guys never grew these before so am after some collective knowledge!!

After finding out which way to plant the tubers I planted them all into pots until I have prepared the ground properly.

So...2 questions. q1- how deep should they be? At the moment the bit that presumably was last years flowers is showing slightly but not sure if this is so.

q2- can I keep them in pots? That way I can hopefully put them where I want them and just remove in the winter?

Thanks all-

 

Not quite sure, it usualy says on the pack how deep to plant. I've only got Bishop of Llandaff and Moonfire (sunshine), they were bought as plants and they are in the ground and have been there for yrs I never dig them up, and up they come every yr bigger and better each time!

 

i bought these all loose so it didnt say. It took me ages to work out which way was up! As you can see I am not au-fait with these things!

 

I panted some dahlias a couple of weeks ago and the pack said 15cm deep. I'va also read a general rule that 3 times the depth of the bulb/tuber, so if they're 5cm top to bottom then 15cm would be right. Not sure if that meant the hole was 15cm or the depth of the soil on top should be 15cm. Any way, they're in 15cm holes!!

 

That seems to be a bit deep Sarah. Mine are almost at the surface or maybe an inch or so below soil level. Planting them deeper should keep them more upright but flowering will be a bit delayed.

 

Thanks for that chobart. Might not be a problem - just checked the card from them and it says 10cm. I'll expect a delay then!!

 

I just plant them at roughly the same depth as last year. ie with the remains of the old stem just showing above the compost. There is a view that many bulb (and presumably tubers) will move themselves up or down if they are planted at the wrong depth.

I see no problem in keeping them in a pot, but it needs to be fairly large. In the soil you can virtually abandon Dahlias as they can find their own moisture and nutrient, but in a pot you must feed and water them.

 

Have just been to the Harrogate Flower Show and spoken to the National Dahlia Society. I learnt a lot today.

Dahlias that have been overwintered consist of two parts. There are the tubers, which are potatoe shaped, and the crown, which is woody. The roots only grow from the tubers; the tubers are attached to the crown; and the foliage only grows from the crown. What this means is that if a tuber falls of - it is of no use unless it is attached to a bit of crown. If you bury an orphan tuber it may grow roots, but it can never grow foliage.

Planting consists of two steps. Chitting (my word - not theirs) and planting. The chitting stage is similar to potatoes. The Dahlia Society had a demonstration, where the Dahlia was laid out ON TOP of the compost in a seed tray. It looked like an octopus with the central crown and tubers radiating outwards. Actually the tubers were half buried, but the crown just sat on the top. I was told that this was the correct way. The tubers can grow roots downwards, but the crown should not be covered. The reason is that if the crown is covered with damp compost it could rot and kill the whole plant. Additionally the light helps to create new growths from the crown. You would keep it like this until the green growth had reached several inches.

At this point you can divide the plant. You can cut down through the crown, splitting it into two or more pieces, as long as each piece has both a growth from the crown and one or more tubers attached. However you can also take cuttings a bit later as an alternative method of propagation.

The second step is planting it in its final position. Plant it as deep as you like, or as deep as you can, was the advice. 4 inches would be fine, but it can be deeper. Once there is top growth, the crown will no longer rot.

 

Peter, that's fascinating and timely advice - I'd just popped on here while checking my planting plan before going out to plant a load of dahlia tubers, so I'll give that method a go. I planted three yesterday, so I'll just have to keep my fingers crossed that they'll manage anyway.
Thanks very much for posting that!

 

Claire, I am sure they will be OK. I started some of mine off some time ago, almost completely buried, and they are doing fine. After the advice I got yesterday I re-did all the Dahlias I had started recently. They were nearly all doing fine, except for Bishop of Llandaff which had a little rot at the crown. It has roots but no growth yet, so I am not sure if it will survive. But the rot I found does make sense of the advice I was given.