By Joanairey
Middlesex,
United Kingdom 
I have just ordered some Dahlia seeds. I didn't actually know you could grow them from seed. I only know them as tubers. However, it was a good deal and we need some tall varieties to go at the backs of borders next year. Does anyone know whether Dahlias are annual, half hardy annuals or perennials?? I have read a few conflicting pieces of information on how to grow them and what to expect.
30 Jul, 2016
Answers
Whether dahlias are annuals or perennials depends on your knowing your growing zone and the plant's growing zone....that goes for any plant you may obtain. The type of dahlia grown from seed will not match up to the ones grown from tubers. They will not be as large. They also need warm temps to germinate so they may have to be started indoors. All the essential information will be on the seed packet or the site or catalogue you ordered it from.
30 Jul, 2016
Hi, there are about 30 species of Dahlia, and more than 20,000 cultivars, they can be roughly divided into 2 groups, tall growing border types, and shorter growing bedding Dahlia's, it's usually the latter which are grown from seed, and are then bedded out when danger of frost has passed, and discarded after they've been knocked back by frost in autumn, or when you want to plant your winter bedding, they will form tubers, but they're so easy to propagate from seed, and it saves having to keep the tubers frost free for the winter' The larger border Dahlia's are usually propagated by cuttings taken from tubers started off in a greenhouse, in late winter or early spring, and should be placed in a propagator with some bottom heat, Derek.
30 Jul, 2016
Wonder if they will ever develop a slug proof dahlia...
30 Jul, 2016
Hi Sue, now that would be something worth having !! Derek.
30 Jul, 2016
I'm first in the queue - can't grow them here at all.
30 Jul, 2016
Whenever I look for my tubers I stored last season, I find nothing but a box of raisins & a pile of saw dust. So for me, they're annuals.
30 Jul, 2016
When I was trying to find out how to grow Border Dahlias here in the desert, I discovered that--in addition to problems with heat--they were one of the most pestiferous plants that I have ever grown! Slugs were only one of an extensive motley crew.
31 Jul, 2016
They are incredibly thirsty plants.
31 Jul, 2016
Previous question
« I have magnificent hydrangea on 50cm pots. I usually prune on March. Moving house...
Next question
Depends on the species as there is more than one . the commonest are the ones that you usually buy as tubers. they are tender perennials. when you grow them they will go on to make tubers so after the first season you can lift them and store the tubers as before.
Welcome to GoY too :o)
30 Jul, 2016