Return to the Dahlia Forum | Post a Follow-Up

 o
Cutting success! How have your cuttings done?

Posted by steve22802 7a VA (My Page) on
Mon, Jun 10, 13 at 9:27

I've had great success with cuttings this spring. Last year I tried some and had only about a 30-40% success rate. This year it's around 95% success! I've even been successful taking cuttings from newly aquired tubers, but it required a lot of courage. It will be great to have 2 or 3 plants of some newly purchased expensive varieties instead of just one specimen. I've got around 185 cuttings that I've potted along into potting soil and about another 100 still in rooting media. I've learned a lot this spring from reading articles online and from advice (Thanks Ted!) shared here on the GW Dahlia forum and this has led to a big improvement in my cutting technique. I struck many more cuttings than I actually need simply as a way to develop my skill set. (I may have a one day plant sale to get rid of the excess as I now have many clones of the same varieties.)

Here's the basic formula that worked well for me: well draining media (I've come to prefer 50/50 vermiculite and perlite), high humidity, moderate temps in the mid 70s, 14+ hours of light and Green Light Rooting hormone powder. I don't know that the hormone is necessary (Ted says no) but I had it on hand so I used it. Next year i think I'll skip the hormone and see if my success rate differs.

Cutting diameter seems to be very important. Too thin and they wilt and rot, too thick and they take forever to root. 3/8 inch seems just about right. I also found that too much leaf area is bad and is stressful on the cutting. It's difficult to explain what the right ratio is but it becomes apparent after you take the first 50 or so cuttings and see which ones look stressed. Most of the small percentage of cuttings that I lost were from attempting to use a sprout that was too thin. i also gave up on a couple of fat sprouts that refused to root after a month even though they had not rotted or wilted.

I used 3 inch square pots and sometimes stuck as many as 4 sprouts into one pot. I pulled the rooted sprouts at around 14-16 days on average so the roots usually weren't too tangled even with 4 in a pot. I shook off most of the rooting mix to reuse and then potted the cuttings along into 6 inch pots filled with good potting soil. (I made many of the pots by cutting gallon jugs in half.)

I used translucent Sterlite tubs to maintain humidity around my cuttings and sprayed them occasionally with a hand mister. The last batches are now on the north side of my house in the shade because the greenhouse gets too hot on sunny days.

cutting_humidity_covers

This nice potted cutting (Boogie Nites) was in rooting media from 5/1-5/20 and then was potted up into a larger container filled with good quality potting soil. I'm amazed at how fast the cuttings grow given optimal conditions, that's a 6 inch pot!

nice_potted_cutting_example

My greenhouse has shifted from pots of early potted tubers to pots of rooted cuttings.

potted_cuttings_in_greenhou

Thanks everyone for your helpful tips and advice! My cutting season is almost done. I still plan to attempt a few tip cuttings from one-of-a-kind varieties that I planted straight out in the garden.

- Steve G.


Follow-Up Postings:

 o
RE: Cutting success! How have your cuttings done?

I love your idea of flipping the clear tubs over flats! I'll have to get a few for next year's cuttings, so I can keep them humid longer.

Did you have the cuttings outside while it was still frosting?

Thanks for posting your successful cutting experience, Steve!

CC


 o
RE: Cutting success! How have your cuttings done?

I took the last cuttings on May 18th. They are nearly ready for planting but most are destined to become pot tubers. I root the cuttings under florescent lights in our daylight basement. Temperature is about72 degrees under the lights. I do not believe I could be very successful in using my greenhouse as the temperature fluctuates too much, It is the heat that is bad. Skinny sprouts root just fine for me but take longer to grow into plants suitable to put into the garden. Like you, I more than one of the skinny ones into pots to root and divide them into single pots later. No rooting hormones or fertilizer is needed to root dahlias. Fertilizer will cause them to rot. A very weak solution of 20-20-20 greenhouse fertilizer can be applied after they root at about 12 days.


 o
RE: Cutting success! How have your cuttings done?

>> Did you have the cuttings outside while it was still frosting?

No, the cuttings were in my unheated greenhouse while there was still a chance of frost. We did have some late frosts this year so the greenhouse was a big help, but I was more often worried about overheating than freezing in the greenhouse during the time I was taking cuttings. I kept the flats that were under the translucent tubs out of direct sun to keep them from overheating.

Ted mentioned fertilizer. What I've been doing is waiting until the cuttings are clearly well rooted (Usually I've been waiting longer than 12 days, more like 14-16 days) and then when I pot them along into potting soil I saturate the soil with all purpose Miracle Grow. Seems to kick them off to a strong start for me.


 o
RE: Cutting success! How have your cuttings done?

I have done really well with cuttings this year too but nothing scientific about the way I do it. When a plant looks too tall for where its growing in my greenhouse I just nip the top off of it and poke it into a hole in the soil alongside its Mom. I would say about 80% of the time they root just fine. When several of my very expensive new introductions rotted I was so glad I had done this! My plants are in regular potting soil at this time, in a small greenhouse, under lights for most of the day. I turn the lights off during sleep hours so they don't bother the neighbors. It seems like where Mom Dahlia grows well, Baby Dahila is quite happy too. From now on, all less common new dahlias I buy will be cloned as soon as possible for insurance.


 o
RE: Cutting success! How have your cuttings done?

Where are you taking your cuttings from? Are they just the tops of dahlias that you snipped off to encourage lateral growth, or are you taking side cuttings, where a side leaf, it's stem, and a little part of the main stem are removed?

Even though I didn't need more plants, I decided to try and see if I could root some tops. I made the mistake of putting my pinched tops indoors in the a/c to avoid the excessive heat and sun. I thought they would die in the heat and sunlight outside. Well, it took a while but most of them just never rooted and died.

This year I've just pinched them and stuck them in different places outside in different soils to see what works.


 o
RE: Cutting success! How have your cuttings done?

  • Posted by kousa Zone 6 (My Page) on
    Tue, Jun 18, 13 at 11:17

Wow, Steve, your cuttings yield awesome results and plants. I have good results too eventhough I do not give them the ideal growing conditions as you did. I found that some dahlias are better at rooting than others. In fact, some of the cuttings that I started in April now have flower buds.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Dahlia Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here