Growing Dahlias

[Garden Manager]

Well its that time of year again when the dahlias have to be 'put to bed' for the winter.

Just spent most of my gardening day today sorting them out, but at least this year have been a bit more organised. Instead of just taking them out of their pots and putting them in store haphazardly (and then not known which was wich next spring on planting them up), I have taken the trouble - whilst they were still in flower- to catalog and label them so that i could then keep track of which one was which. Each plant was given a letter code which was all that was written on the label whaich once the tuber was removed from soil or compost could be tied to the tuber with twine.

I normaly grow my dahlias singly in large pots, so lifting in autumn in usualy essential - no option to leave them in the ground over winter. However last year i tried a couple of plants in the ground and as an experiment, left them in the ground with a heavy mulch over them. On inspection this spring i found them to be fine so decided to extend the number planted out (to 7). 2 had to be lifted as they werein the wrong place tbut the other 5 will be left in with a pile of dry mulch over  the top of them. With luck and not too hard a winter they should be OK (2 survived last winter outside and turned out to be the 2 best plants this summer/autumn!).

If all is well i plan to put even more of my collection out in the ground next spring in the hope that I can leave most if not all in the ground and not have to worry about storing them. Even if i cant leave them in the ground  i still want to grow them in the ground during the summer, as i have found they are getting too big for the pots and are not lasting so long in flower. In the past the problem has been lack of space in the borders for them (hence growing them in pots), but now i have resolved to make space for them, filling the gaps where they are to grow with spring bedding which should be over before the dahlias need the space.

I would be interested to know how many other dahlia growers ther are on A4all. I am particularly keen to hear how/where you grow yours (do you lift to store or leave in over winter for example). Maybe we can exchange growing tips!

[Garden Manager]

[teresa]

One of the most rewarding plants going, I love my dahlias.
normaly lift and store plant in pots in spring and when growing a few inches( slugs dont bother then) plant out well manured ground and stake and tie up when needed.
Best one was 3 years ago visiting family, they had a purple pom-pom fell in love with it. Asked what they were doing over winter they said leave in the ground I said I would love a seed head which was ignored.
Oh well later went out for a cigerette and no one around fingers started to itch so pinched 3 seed heads. It was raining so went inside and up to the loo with handbag. My trouser pocket was soaked, with loo roll dried pocket and more loo roll wrapped seedpods and put in handbag.
When I got home got my seedpods out OH said you did'nt  well I had asked and then helped myself hee hee. When dried got loads of seeds which were set the following spring.
Grew lovely and planted some outside the house and some down lottie between blackcurrant bushes facing the dirt track which dog walkers use.
Well they were in full flower when the said family member came to visit.
Not one pom=pom in site but were single, semi and double small dec. every colour going. Oh says she, what lovely dahilas mine died did you buy them no says me grew them from seed. OH his face was a pic and how I keept a straight face I will never know.
The ones at home I lifted but so small tubers never made it through the winter but the 10 down lottie I lost 3 so 7 came up this year. What a size they were so will cover them again this winter.
I think if you have light soil overwintering in the ground with a good mulch will work.

[wahaj]

first year i grew them. i just had a pink dawrf variety. they lasted....well forever. they went from very early summer, all the way till the frosts last week....and each flower was perfect. and they were also very disease resistant. i have lifted mine.....and it's in a paper bag in the shed....but i don't know how well it'll keep.

though something amazing i saw in someone's front garden the other day. giant dahlias. they were probably about 7 feet tall and each flower was about the width of my face. they were magnificent plants. i've no idea which garden centre near here sells them...but if i see them again, i'll pay anything for them.

[Emagggie]

Have always left my dahlias in until last year.Thought I ought to lift and store them properly. Disaster struck and only the two corms I took up to the plot did anything.Maybe it was my soil at home,I don't know, but bought some to replace and the slugs ate the lot.Tried again and had partial success. I shall be leaving these under mulch this time. ;D

[teresa]

The large dinner plates, are show dahilas, join a club or check the net for a specialist grower. Not found in local garden centres.
Dry the tuber out upside down so moisture comes out of the stalks. then clean off soil and cut damaged parts allow to dry. Pack in  a box with peat all around put frost free untill spring. Then pot up in fresh compost and grow in untill fost has passed. If you plant tubers in the ground slugs fined the new shoots and chew older shoots they dont bother with.
If you leave in the ground do check in spring and protect from slugs eating the new shoots comming through.

[Mrs Ava]

I am a new convert to dahlias and I love them.  I have grown all of mine from seed over the last few years and have no idea of varieties but have a mix of singles and doubles and lots of firey colours.  I leave mine in and just cut them down and put a good mulch of leaf mould on top.  The slugs really will go crazy for them if I don't keep an eye on things, so as soon as I see life stiring, slug patrol begins!  My garden is shadey so they never really get much higher than 3 or so foot, but I don't want them for cutting, so that suits me fine. 

LOL at Teresa!  Shame they didn't come true from seed though, typical letting them die when you could and would have willingly babysat them on their behalf!  ;D

[teresa]

Yep your right EJ, I would have taken such good care of in and took cuttings hee hee.
But as a friend said who in their right mind leaves me in a garden alone? I do have a rep hee hee.
I have bought a packet of pom-pom seeds lets see if I can get one purple ha ha. They do grow so easy from seed, bought or pinched ha ha

[Garden Manager]

I really only have two concerns about leaving them in over winter. One is wet and the other is slugs and snails. The plants are well mulched and I am in a mild area so cold isnt so much of a worry. However my soil is not light, and might given a wet winter get too wet for the dahlias. Last winter whaen I overwintered some, it was in a free draining raised bed in the veg plot, and I did cover the mulch with plastic to shed water. That said the borders the dahlias are in now are sloping and the mulches dry so hopefully this will be enough to stop the tubers getting too wet if we have a lot of rain over winter.

As for slugs and snails, they did nibble the ones I planted out (dormant) this spring, but being a dry spring slugs and snails werent a problem and the plants soon grew out of it (big enough plants to cope with a bit of damage anyway). The worry is if the winter is mild, and the spring a wet one then slug and snail damage could well be a big concern. I shall of course cross that bridge when I come to it.

It could well be I need to lift in future simply to protect the tubers from wet and slug/snail damage rather than cold.

[caroline7758]

I've also grown them from seed for the first time this year and found them easy, although I did post a question recently about too much foliage & not enough flowers.
I'm also at the stage of wondering whether to leave or lift. Think I'll leave the ones that are in the ground and lift the ones in pots and see what happens.

[Garden Manager]

I've also grown them from seed for the first time this year and found them easy, although I did post a question recently about too much foliage & not enough flowers.
I'm also at the stage of wondering whether to leave or lift. Think I'll leave the ones that are in the ground and lift the ones in pots and see what happens.

Unless your garden is a cold one, it should be worth the gamble. You are best to 'lift' those in pots thoughas they are more exposed to frost than in the ground.

[Heldi]

I'll be lifting the ones in my back garden as I think it will be way too wet for them to survive. I'll store them in trays and/or pots. I left a decorative in the front garden completely by accident a couple of years ago. It has come up a treat ever since so after adding a few more to the front this year I'm thinking I will leave them in. I think they should be fine as it is much drier out the front...facing west. There is a cactus type which is pale cream going to pale pink on the ends...I really like it , am in a bit of a quandry about that particular dahlia. I'll probably risk leaving it in the ground as I don't really have alot of space to overwinter the tubers.  I've planted four at the allotment this year. I'm going to leave them in as there is very good drainage and I am using the spent sawdust from the chicken shed to mulch. Just experimenting really.

I've got one of those huge dahlias Wahaj. Big white one. They are stunning aren't they. I sent away for it a couple of years ago. Think it's called snowqueen but I'm not too sure? I can never seem to give them enough support to keep the flower heads up so will be thinking hard about that next year.

[wahaj]

true....they do look a bit top heavy.

I don't intend on lifting many bulbs next year.....not even the glads. My neighbour leaves his in the ground. I've been told that as long i plant them deep enough with a centimeter or two of grit or gravel at the bottom they should be fine. and then if you mulch them on top.

I'm sure it's probably cheaper to just lift them but if you're dealing with a lot of bulbs that need to be lifted...it'll probably be worth while.

[caroline7758]

Any opinions on the best medium for storing them in? I've read peat, vermiculite (too expensive!) and coir. What about sand or ordinary compost? Is it just to keep them warm?

[teresa]

I get B+Q multi compost, fresh compost is better than used just in case of vine weevil, dry compost keeps them frost free and the tuber does not dry out too much for next years growing. I box mine makes storing easier in greenhouse ( unheated) or garden shed.

[Garden Manager]

Those of ou that lift, do you go to the trouble of labeling them, or do you just take pot luck with them?

I started labeling mine for the simple reason i have many different types - tall short, different flower shapes and colours. I used to just take pot luck, but it used to be very hit and miss which ones i put where and this year ended up with a few that were wrong for where they were planted. Plus since i am now planting more out in the borders, i need to know that the dahlia i am planting in a cetain spot wont be too big for the site , or the flowers clash with those around it.

I also need to know that the ones I feel need to be planted out in the garden actualy end up there, since i wont have room for all of them in the garden and some will have to stay in pots.

[teresa]

If you lift its best to lable, lables with holes that you can thread string and tie to the dying stalks works.
Or pick up different size boxes from supermarkest and lable each box this works if you have two or three the same.
Tip is to lable before lifting, you can put the colour and discription on lable. Makes lift easier come the spring so you can put the big ones at the back and smaller ones at the frount.
Lottie ones are left in place just put extra ones in if I lose one or two. They look nice and attract the bees etc for pollation the runner beans.
Using woodshavings this year as a mulch from hens recycle is the name of the game hee hee.