Potatoes in a tub and Dalia tubers in a pot?

BML

 I would like to have a go at growing potatoes in a tub and wonder if I could do so using last years Tomato Grow Bags.

I have bought some reasonably expensive Dalia tubers and read on one packet that they should not be grown in a pot.  Does that make sense?

JennyJ

Last year I grew potatoes in big tubs (halves of old water butts) in a mix of old compost, homemade compost from my bins and quite a lot of chicken poo pellets, and the crop was OK.  Potatoes are hungry plants so you'd need to add something to the old growbag compost.

Not sure about the dahlias.  If the pot is big enough and you can give them enough water and feed, and support them if they're not a short variety, I don't see why it would be a problem.  If you want to keep them for next year, you'd need to move the pots somewhere frost-free for the winter (or lift and store the tubers) whereas in milder areas they can be left in the ground but pots left outside are more prone to freezing.

fidgetbones

It depends on the type of dahlia. If it is one of the large flowered or dinner plate dahlias, mine got to 6 ft last year in the ground.  They had enough top  growth to need supporting with large canes and a cats cradle of string.

What variety is it?

BML

Sunlady and All Seasons

Littlegrower

I've grown the pompom dahlias and small bedding dahlias in pots and they grew very well. But larger ones I grow in the ground, having tried to grow them in post they don't seem to grow as big and blooms are fewer. As Jennyj has said a big pot may work, my pots weren't so big.

fidgetbones

Both of these will grow 4 ft tall, so will do better in the ground.

BML

I started to plant the Dahlias today after not touching the garden for over a year as I was not up to it.  I would like to plant them in a border that I covered with ballast after placing a weed membrane over it.  I cleared a space of ballast and found that when I cut through the membrane the soil was very dry so I cleared some of that out and mixed the rest with compost.  Another question; Do those corms require any form of fertilizer?   

fidgetbones

I start dahlia tubers in a pot in the greenhouse. I use standard multipurpose compost, and use the smallest size I can comfortably fit the tubers in. When they start growing, they rapidly fill these pots, and I then pot on into a bigger size, with a sprinkle of Blood fish and bonemeal to pep it up a bit. By May they are in florists bucket size pots. When frosts are done towards end of May, I dig a big hole and plant. I backfill  with the soil and a about four ounce of blood fish and bone to each plant.  I make sure they are well watered through the summer and staked well.

nultyphilip224

@fidgetbones,..beautiful selection of blooms and colours.

JennyJ

BML said:

I started to plant the Dahlias today after not touching the garden for over a year as I was not up to it.  I would like to plant them in a border that I covered with ballast after placing a weed membrane over it.  I cleared a space of ballast and found that when I cut through the membrane the soil was very dry so I cleared some of that out and mixed the rest with compost.  Another question; Do those corms require any form of fertilizer?   

If the soil is good they shouldn't need any extra fertilizer as well as the compost at this stage.  Give them a feed later in the summer if they look like they need a boost.  What they do need is plenty of moisture when they're growing so if the membrane isn't permeable, don't put it back around the plants.