Dahlia Corms

Evening all,

I planted some bedding Dahlias earlier in the year, and they have done very well. I have had to pull one up as I needed the space for the Snowdrops that I got from Silu. As I expected they have produced corms where there was just a root ball before (see pic below).

I have learned that I have to dry them off and keep them frost free for next year, but my question is..... Do I split them into individual corms, or leave them in a bunch as in the pic?

Thanks for looking in and any and all advice is appreciated.

 

Looks like you've got a helper there! .......my cats like to help out too. Sorry that really didn't answer your question. Someone will be along shortly with more knowledge than me.

 

They have formed nice tubers Gdnam, dry them out and keep somewhere frost free until next spring, then plant them in trays with some damp compost and they will "sprout" which can then be cut into separate plants.
We can go into more detail in Spring.

 

And I thought Gdnam was wearing some very slinky but fetching gardening gloves
If I can tag onto Gdnams Dahlia post............I have a few cactus Dahlias which are still flowering well , when should I lift them?

 

Indeed, that is Clover, she is a cat version of a Jack Russell, rarely leaves my side when I am in the garden

@pamsdish , thanks, so leave as they are following your above instructions and I should be good to go in the spring. Sweet. I expect to have some losses, but I have lots of them so should have a good number of tubers that survive. Not sure I have deep enough trays though , will have to have a hunt around for some deeper ones.

 

Would be nice and cozy in winter if they were gloves

As to your question, I think you treat them just like non-cactus, wait until the frost blackens them, and then lift. ( I will probably be corrected, by more knowledgeable peeps).

I had to lift this plant early, as I needed to plant some Snowdrops, right where it was. Looking at the forecast I think I might get another couple of weeks out of the rest, before 'jack' puts in an appearance.

 

Yes lift your dahlias, any type, when the frost blackens them, you will need to keep them protected during the winter, submerge in dry compost , wrap in newspapers. mice will chew them so protect from them as well.

 

When you buy them, there is always a nice clump of joined tubers, so that each bought tuber will form a good big bushy plant with multi stems. If you separate the tubers then each individual section will only produce a few stems, making a less bushy plant.

Not sure if you could fill a bigger space and get a better show by planting the entire joined tuber, or by separating them and planting out as a group, say, 6" apart. Anyone know?

The tubers are fragile, and bits drop off. Sometimes these will sprout, but as Loofah says, they may not. At this stage the 'eyes' are almost invisible, they are found at the base of the old stem. So if the piece still has old stem on it, it should sprout. If not, it won't. I know, I've tried!

 

Thanks for that info. There were no tubers when I planted them, as I think they were probably grown from seed, they were purchased in a tray pack from a store beginning with 'M'.

I'll do a test, one plant I'll re-plant as they are (like in the pic above) the others I will split, and we will see what happens

 

Be aware that Dahlia growth doesn't come from the tuber itself - in the way that a potato does. The tubers are purely storage organs and are part of the root. The tubers are attached to a woody crown and the growth comes from this crown. So if you want to split them, then make sure every section has part of this woody crown. If you plant just the tuber by itself it won't grow.

 

Good tips Peter and Madahhlia , as I am a Dahlia newbie , I will dig them up and leave the tubers and crown as one They are still flowering really well and its clocks back this weekend and November next week ..sigh....

 

Personally I wouldn't split a clump as small as that. However, in spring you can start the tubers off in a pot / tray (in greenhouse / conservatory with some heat) and then take cuttings off the shoots that sprout up.

They may have been grown from cuttings - they, as young plants, wouldn't have had any tubers either.

 

I've never lifted my dahlias and they seem to come up year after year with no problems - I do most of my gardening through beginners luck or benign ignorance though! I do want to move some of them for next year though so will follow the advice above. Is it important to wait till they're frost blackened?

 

I haven't lifted mine for quite a few years. What I do is: after the frost kills the top of the plants I cut the blackened stems to 1/2 foot above ground, then I put some straw in/around/over the remaining stems, afterwards I place big upturned pots over the plants. When spring comes, whenever the weather is good I take the pots away to give the straw a bit of an airing and maybe kill some hiding slugs and snails as well.
Some time in May I clear away the straw and dead tops, young shoots will be up soon after. Make sure you control the slugs and snails, they attack the young shoots mercilessly. I haven't lost a single plant with this treatment. They maybe start a little bit later than those that are taken out over winter and started indoor in the warmth. But it does save a lot of hastle.