perennial dahlias

countrywoman

I planted some shop bought dahlias last year. I thought Dahlias were perennial but these were not

I see Dahlia's in a neighboring garden and they come back year after year
Are there different types?

redser7

People mostly dig up their dahlias in autumn/early winter, dry them out and store them indoors. Then they plant them out again in the Spring. Are you sure they aren't doing that? In sheltered spots they can survive in the ground with a mulch but it is a risk if you get a very cold winter.

looksee

They may have died right back, but still have time to come again, look out for slugs getting them as soon as they peep through.

Supercell

I remember reading that in the British isles that Dahlias can be left in the ground all year round as long as they are planted about 5 inches down. Obviously if the ground is very heavy and wet they will probably rot overwinter though.
I'd imagine if you lived in the midlands or somewhere likely to get a harder frost then maybe a layer of mulch or wood chippings would help to insulate a little more.
Where I am close to the sea, I havent bothered and they do fine, the slugs are a bigger nuisance than the frost here.

Marhay70

I am an untidy gardener, in the sense that I don't like formality, I like to mix things up, so I have Dahlias planted with Lilies, Rudbeckia etc. I have never dug them up and they come back every year, the only attention they get is a mulch of compost. They have been there even during the winters of 2010 and 2011.
"Bishop of Llandaff" is a particular favourite.
I live in the sunny SE of course but that is not always a guarantee of tropical conditions, very much the opposite in recent years

thegardener

It is still very early in the season and Dahlias left in the ground will often not show any signs of new growth until May. Watch out for slugs at this stage as they will destroy young shoots. Good luck.