Narcissi being planted in trough on balcony 14th October 2020

You'll have a fantastic show there David ..

I certainly hope so, Amy!

Can I plant Dalias this way?

Depending on the size of the final plants, yes, you can. In a trough the size of mine you could comfortably put in up to six small Dahlias. Perhaps three medium size ones but probably no more than two big ones, at most.

Dahlias are very hungry plants & would need feeding at least once a week with a tomato or rose fertilizer in liquid form. They would also require quite a lot of water.

I've grown small Dahlias in these troughs on several occasions & they have done reasonably well. Not great really but good enough.

This year I had some Dahlias on the balcony that I had kept over winter frost free. They came from some free seeds in a gardening magazine. Unfortunately they didn't do nearly as well as I had hoped & I have decided I'm not keeping them for next year.

I bought dahlia bulbs today. I thought of planting some in a long pot like yours. But, seeing your comments about feeding them weekly, I was averse to the idea. I think I'm going to plant it on the ground.

It's probably the best thing to do. Dahlia tubers, especially if they are big Dahlias, need to be planted deeply so they have the support they need. I wouldn't think of planting big Dahlias in troughs like I have on the balcony - they wouldn't get enough support from the compost & the wind would blow them over. There isn't enough depth in the troughs to hold them up.

Thank you for your comments and suggestions