Hi there,
can`t add anything myself,
perhaps that thread helps.

Could you post pics of your actual cuttings and your set up? So far, your methods described sound ok. Perhaps some minor detail is off

and some of the more professional growers from the GW-bunch could comment on it.

God luck,

bye, Lin

Here is a link that might be useful: GW thread on cuttings

Thank you Lin for your reply. I'm going to try the suggestions from the thread you provided. I wonder if my cutting 'room' is infected with too many mould spores. The room I'm using is a cooler that I stored tubers in a few years ago. Just reaching for answers!

Henry, how long are your cuttings? They should be 3-4 inches, with the bottom nodule stripped of leaves... That is where the roots will start from.

The only time I have killed cuttings is when I have inadvertently let them dry out. I have tried multiple mediums, and all work, but I found that I prefer wet floral foam the best, leaving a bit of water at the bottom of the Dixie cup. I put
all the cuttings in a clear storage container with lid under lights with no rooting hormone or fungicides. Ten days produces roots.

Try this thread from last year, too...

Be sure to open the link 'Cuttings from a Pro' half-way down the posts. Great stuff in there.

Hope this helps!
CC

Here is a link that might be useful: Would you take sprout cuttings from a newly received tuber?

This post was edited by CCvacation on Tue, Jan 28, 14 at 23:15

I've tried the Oasis foam and I still get some damping off. Now, I'm trying to root them in a cup of water with a rooting hormone. It's been 5 days now and I haven't lost a single cutting...yet.
I'm also trying the method described in the thread that linaria posted above. I've lost a few cuttings but I don't think I started them off right. I had tried to start them in soil first but when they started to show some decline I transferred them to the sand/water combo.
At a previous employer, I rooted thousands of rose cuttings and grafted tree roses and had good success. This has got me stumped! Thank you all for your input! Henry

I root over 1000 cuttings each year and the overall success rate is about 97%. We use no rooting hormones. All pots and flats are soaked in weak bleach solution prior to use. We use a peat moss based product called germination mix as the medium. The cuttings are placed in the pots with the germination mix and 36 pots are placed in a 10 x 20 tray and the tray placed into a "13 gallon" kitchen garbage bag and placed under florescent lights at a temp of about 68-74 degrees. All cuttings are removed from the tuber by cutting them off just above the tuber and the cutting includes the primordial leaf nodes that are there. That is important as it is these multiple nodes that produce roots.
Let us know if your cup of water cuttings root as I have never heard of this method.

Teddahlia - Do you get any damping off? What do the 3% die from? Do you think a rooting hormone injures the cutting? Do you use 2nd generation cuttings i.e. cuttings from a cutting?
I got the idea of rooting in water from a thread that "linaria" posted above. It has been 5 days since I first put some cuttings in water with some rooting hormone. So far, they're all alive and look healthy.

Gee,
I didn`t mean to recommend water.
Sand or seedling potting soil should do well.

Damping off is caused usually by:
too little light
too high temperature
too much moisture/ damp air/ poor ventilation
in combination.

could you post a pic of your set up? That could give us a better idea and perhaps someone spots a clincher/ cause for your underperforming cuttings.

Am starting some tubers next week and will post as well if I get some results.

Good luck,

bye, Lin

Hi Lin - Sorry...the reference to using 'water' was written in the post from the link that you provided. It wasn't one of your suggestions. However, I am trying it and will keep you posted! I'll try to get some pictures over the next few days.
Henry

Teddahlia - Do you get any damping off? What do the 3% die from? Do you think a rooting hormone injures the cutting? Do you use 2nd generation cuttings i.e. cuttings from a cutting?

Most of ones that do not make it have rotten leaves and a black shriveled stem. The others were errors in taking the cuttings and there was no leaf node to make roots.

Rooting hormones are supposed to be used in minute quantities as they inhibit rooting and kill plants in high doses. They are entirely unnecessary for dahlia cuttings although they may stimulate some that are slow to root. Why risk exposure to toxic chemicals for no benefit?

We have taken many "cuttings from cuttings". One roots a cutting and grows it on until it is about 14 inches tall. You then take what are called leaf cuttings. They take 50% longer to root and even then are smaller than cuttings from tubers. This process is only worth doing if you really need to multiply a variety quickly and the resultant plants do not make very many tubers.

I don't know if this will help you but it sure helped me: soak your cuttings in an inch of water for 2 -4 hours, apply rooting powder at the cutting edge, dust off excess before you put them in the pot. Last year, I got very good rooting success by doing this. Soaking allows the cuttings to uptake water so they will not dry out and you do not have to water them too much.

Since we place them in the plastic bags, we do not water them at all for the 12 days or so that it takes to form roots. We make sure the pots have sufficient water but are not wet by any means. The reason we place them in the plastic bags is that they need no attention at all during the 12 days. In commercial greenhouse they mist cuttings to achieve the same results. Again, using rooting hormones is not necessary at all and it is too easy to overdose them and the chemicals can be toxic to humans.

I read Ted's advice and then mostly I just pinch off a piece and stick it in a pot of potting soil in my greenhouse. I would say about 90% of them root. They WANT to root. I just don't get in their way! My greenhouse is heated over the winter to keep it above freezing, but once the winter freezes are over I try to keep it at about 70 degrees, or a temperature that feels comfortable to me. It maintains a temp in the 60's and maybe goes up to 80 on a clear day before the vent opens and lets heat out. The air in my greenhouse is moist. If I take a cutting that has the extra leaf node, strip off the lower leaves and stick it into moist potting soil it grows because it wants to.

If your basement area is too cool, too hot, too moist, too dry, the cutting will not be able to do what it wants to do.

Forget the rooting hormone. That is just making money for someone else. Plants know how to make new plants by rooting themselves! It is the plants defense against being trampled by a herd of 4 legged beasties. Some broken bits get pushed into the soil and after the herd moves on they root and come up again.

I start all my tubers in 4" pots. When they start getting too tall I pinch the tops out of them and root the pinched off pieces. The potted tuber grows bushier and the rooted cuttings make more of the plant. Just make sure there is a leaf node on the stem and that you have removed the leaves that were growing there. That is where the new roots will grow.

We have not heard any recent results. Have you been successful?

Yes, I have! One of the big reasons for success...I think...was moving the initial propagation area from an insulated cooler, with overhead lights and bottom heat, to a basement with overhead lights only. The lights are approx. 8" above the plastic domes which cover the trays. I also tried the sand method which worked well. If you recall, this method involved sticking a cutting into a small container filled with sand (with slits in the bottom) and then placing this container in a larger container filled with water. I did have some success rooting in water only. However, this took substantially longer. I didn't use any root hormone and had about 95% success with the enclosed dome method.

Oops...should read 8" not 8'!!

A scientific study was done to determine the best temps for rooting dahlia cuttings. About 70 to 72 degrees is best. Bottom heat is too hot for cuttings.