Dahlias in pots

[Moonlight]

I want to grow some Downham Royal in pots. woodforddahlias6 has mentioned in another thread that he is going to grow some in big pots. What size would be a reasonable size? I want 1 Downham Royal either side of my front door and we have a problem with shade in our garden, I thought that having them in a pot would mean at least I could move them into a better position if I had to.

So what would be a reasonable size for a single small ball?
What about a medium?

[markb]

Feb 8, 2013 14:36:52 GMT Moonlight said:

I want to grow some Downham Royal in pots. woodforddahlias6 has mentioned in another thread that he is going to grow some in big pots. What size would be a reasonable size? I want 1 Downham Royal either side of my front door and we have a problem with shade in our garden, I thought that having them in a pot would mean at least I could move them into a better position if I had to.

So what would be a reasonable size for a single small ball?
What about a medium?

I grow a few in pots in the greenhouse using 10 litre pots and Canna Professional Coco Fibre. For growing outside a bigger pot and a soil-based compost such as John Innes No3 would probably be better as the extra weight of compost would prevent the pots blowing over in wind.

The plants would still be quite large and would need three or four canes and garden twine tied around them to stop stems snapping.

[scrumpy]

I use 30 litre polypots...size wise about 15" diameter and 12" depth.
With that and a decent compost , and plenty of water, you can grow dahlias as well as in open ground....better in some cases.

[Deleted]

Feb 8, 2013 14:36:52 GMT Moonlight said:

I want to grow some Downham Royal in pots. woodforddahlias6 has mentioned in another thread that he is going to grow some in big pots. What size would be a reasonable size? I want 1 Downham Royal either side of my front door and we have a problem with shade in our garden, I thought that having them in a pot would mean at least I could move them into a better position if I had to.

So what would be a reasonable size for a single small ball?
What about a medium?

I use 23cm plastic pots with a compost mix of 50/50 erin multi-purpose and John Innes No2.

Each pot will either have an individual matching drip tray to aid watering or a large black tray such as those used for grow bags, the larger ones will obviously accomodate more plants, usually 4-5.

DONT !! use teracotta pots as they will dry the compost out too quickly if the weather is hot.

You will need to stake each lateral using only thin canes to avoid taking up more space in the pot and also thick heavy canes will add the weight.

I also place a couple of cornish pebble stones in the base of the pot to add a little weight, a fully grown dahlia can be heavy and easily topple over in the wind.

Not all varieties Like the restraints of a pot, most will grow outside better in open ground. Nearly all will be restricted in bloom size, so you may have to limit the number of lateral stems in order to achieve the same bloom size.

For instance:

Winholme Diane - 7 up, in a pot 4 up.
Grenidore Pastell - 8 up, in a pot 4 up.
Mary's Jomanda - 16 up, in a pot 8 up.

I find its about half of just a little over.