What are your air and media temperatures?

My understanding of hardwood cuttings (for both deciduous woody plants and needled evergreens) is that low air temperatures (45-50?) paired with warm root zone (such as you have) will encourage rooting and delay bud break.

I have a pretty similar setup to yours, temperature-wise, right now - I'm expecting to see bud break on both my deciduous cuttings and my needled evergreen cuttings before they are rooted.

I'm not too worried about the new growth, since I'm propagating under fog, but I have read that bud break before rooting can significantly reduce the rooting percentages (reason suggested was that the carbohydrate stores were going towards shoot growth and not root growth).

So this round of cuttings for me is pretty much just an experiment: will I get decent rooting percentages despite early bud break?

I'd love to hear updates on how yours end up doing.

Most of the easy to root conifers have scale-like leaves like Thuja, juniper, Chamaecyparis, ect... I've only rooted a few that had true buds, but never had bud break before roots were formed... I'm thinking your air temp might be too high, and it's unlikely that without roots the cutting will be able to support bud push, but who knows... hope for the best.

I once grafted a strobus scion that had a cone on it, despite being told by others that it would take too much energy away from the bud push... They were right, the graft was successful and the buds pushed, but the cone was pulling a lot of energy and I could see it expanding, eventually the bud push ceased and the graft failed. All the ones I removed the cones from did fine. The point... grafts and cuttings are in a vulnerable state and cannot support much

I have two separate batches. The one that's pushing is just sitting in my living room, south facing window, no heat mat or anything. This is the first time I've ever propagated pine cuttings and they all (based on the samples I looked at) have callused, but so far no root development. I bet these will be a loss.

only been stuck for about 30 days

==>>> thats not a long time .... in tree time ....

i suspect the the ones pushing.. will dry out all stored moisture.. and ergo.. not be able to use interior stored energy ... and without roots ... its not like you can fert them ....

i didnt know you could root pines.. go figure ...

ken

Brandon,

I've read that 40-50F is ideal for ambient air temp for rooting. Can't say anything from experience. 72 F bottom heat sounds a little high but 68-70F is what I've read would work so not too far off there.

Is there any way to move that set up to a cooler location?

And remember, you can take most conifer cuttings all the way to the end of February so a remake is still possible.

Not sure about the ability to root pine question.

But, cheer up! I haven't been able to do anything so far but I think about it every day. :-) maybe in a week or so.

Have others gotten pines to root very often? I'd think at the very least success would depend on quite specific conditions being provided.

Also the type of pine, I'd imagine? I'm planning to try mugo pine cuttings this coming summer, mainly because they are actually supposed to root reliably if taken at the correct time. I've read very little so far that suggests decent success rates for other types.

Can you link to the article? I'm curious.

I've not tried to root conifers but I've rooted quite a few other woody or semi-woody plants and often saw bud break before rooting. I've rooted some things that took up to a year to root (Vitex negundo, Leucadendron) and they budded and leafed out before rooting. They formed a callus reasonably quickly, so I knew that they were making progress. I have no idea if this has any relevance for conifers!

One of the risks cited for bud break of hardwood cuttings before roots form is that the new leaves, unsupported by a root system, can die. How did you address that, Sara? Did you take any steps to, for instance, maintain high humidity around the cuttings to support the new growth until roots formed?

I know nothing about rooting pines, however for figs, you are supposed to start the cuttings in a dark place else the sunlight could encourage premature bud break. However, once the leaves form, you should give it light or it will rapidly use up it's energy reserves trying to grow and reach the light. For this reason, if a dormant tree placed in a garage to overwinter happens to break out of dormancy, it's recommended that you provide light to the tree.

Speaking of mugo pine finding out how named cultivars of this species are mass produced could be instructive. Named cultivars that are supposed to be uniform, as when cloned. As opposed to seed raised stock, where there is a history of shearing having been used during production operations to make them look all alike.

I had read that mugo pine is one of the only pines that roots fairly reliably from cuttings - but only as summer cuttings taken when the new needles are almost full length. Is that what you mean? I don't quite understand your second sentence. Are you suggesting that many growers claim seed grown stock is that of a specific cultivar, and shear the plants to hide the lack of uniformity inherent to a seed grown population?

I had more scions than understock for one of the strobus brooms I found this year, so I did 5 seconds in dip n' grow 5x concentration and put them in a humidity chamber with 72* bottom heat in indirect sun. I also added Tsuga diversifolia 'Minikin', Taxus baccata 'Repandens', Cephalotaxus harringtonia 'Korean Gold', and Picea glauca `Sander's Blue'... Only 1 or 2 of each, so not great odds, but well see...

I think assumptions are made based on the writings of Dirr. I know people treat that as the bible for propagation, but I find it somewhat useless... It basically just cites various studies, often contracting each other. Like Aucuba japonica, it gives these long winded instructions, yet It roots 100% in just a glass of water.... I know nothing about the author, but if he had first hand experience with this stuff, I can't understand why you wouldn't mention the simplicity of rooting those.

Why such a low hormone concentration? Has that been successful for you previously with those conifers?

And which of Dirr's books are you talking about here? His "Reference Manual of Woody Plant Propagation" with Heuser has only simple instructions for Aucuba japonica, which basically boil down to "take cuttings almost any time, easy to root" .. and in his "Manual of Woody Landscape Plants" it is literally just one sentence saying the same.

5:1 is actually the strongest concentration recommended for hardwood cuttings. Yes, I've successfully propagated a good amount of conifers and broadleaf evergreens with that %.

Yes, that's the book. Nope, he goes on to talk about using 3000 ppm of IBA rooting hormone... That is totally unnecessary with Aucuba japonica... It should have just said, No hormone required, place in water and wait for roots to grow... or put in peat/perlite, but water is more effective.

I find a lot of the recommendations are overly complicated and based on multiple studies that sometimes contradict each other. Anyways... rant end... but I'm not a fan of the book. I guess my point was not to assume it can't be rooted just because Dirr says so. The OP has 100% of his Pinus strobus cuttings callusing after just 30 days!

The information given by the manufacturer for recommended dilutions is extremely vague, and quite understandably so. A 5x dilution for Dip 'N Grow is only 2000 ppm IBA and 1000 ppm NAA, or 0.3% hormone (combined). A 2x dilution of Dip 'N Grow produces 5000 ppm IBA and 2500 ppm NAA, or 0.75% hormone. Most information I've found for harder to root species (hardwood cuttings especially) is for 0.8% to 1%, occasionally as high as 2%. Many of these are for IBA only, but similar recommendations involved a mix of IBA and NAA with comparable totals.

You didn't exactly answer my question, so I am still curious: have you rooted those specific conifers with that concentration? If not (yet), which others have so far been successful?

I am really not interested in getting involved with your rant about Dirr, but as far as your comments about the effectiveness of water rooting Aucuba are concerned, there is another thread going right now that discusses in depth some differences between rooting in water and in soil. Take a look - it might help explain why you don't see water rooting recommended in more publications that count professionals among their target audience (e.g., Dirr), even when it may be possible for the plant in question.

https://www.gardenweb.com/discussions/5572987/rooting-cuttings#n=4

illstep I did keep humidity high. I did this in my greenhouse, which in winter is extremely humid and the rest of the year I had them covered with a plastic dome. The Leucadendron is fleshy-leaved and evergreen; it looked and stayed pretty normal. I don't remember the Vitex much but I have some planted in the garden from my cuttings so they worked! I was really going by the seat of my pants. I don't do well with this kind of project because one has to tend it so carefully for so long, but I did the hardwood cuttings during a time that I was growing a lot of plants for Master Gardener sales, so I was overseeing thousands of cuttings. I may as well have had a baby given the amount of nursing they needed. I swear I didn't travel for a few years because it was too difficult to find someone to take care of them.

It took a lot of digging but I finally found the article that claims Pinus are a 1 out of 4 on the rooting difficulty scale.

I blocked off the air vent to that bedroom, so the air temp has dropped into the mid 60s, hopefully to fall a bit lower as time goes on. It's -4 degrees here, so I'm sure that that bedroom temp will drop more as the building starts plunges into a deep freeze.

Oh, a greenhouse in a mild zone - lucky you!

A second question:

If the callused tissue is "like the stem cells of the human body", what is the reasoning behind doing a quick dip on a freshly cut stem rather than sticking cuttings and then dipping them after a callus has formed?

I'm doing some experiments now on the pines that have callused. Since they were all dipped in hormone in the beginning, I can't actually test my question, but I took five cuttings with a callus and dipped them again just now, after about ~40 days, and I'm going to see what happens. My hypothesis at the moment is that those cuttings will root faster with the second dip..

Brandon - I was actually looking up that same question a day or two ago. I wasn't able to find much, but I did find that some plants are supposed to produce new roots primarily from the stem under the callous, and some can produce new roots from the callous itself.

@illsstep - No I have not rooted any of the conifers I am attempting right now. In the past I've done the following:

Successful: Thuja standishii × plicata 'Green Giant', Juniperus horizontalis 'Blue Chip', Chamaecyparis obtusa 'Lemon Twist', Tsuga canadensis 'Gentsch White', Chamaecyparis obtusa 'Mariesii'

Failed: Abies numidica 'Glauca', Picea abies 'Bird Park', Sciadopitys verticillata, Tsuga chinensis, Cryptomeria japonica 'Knaptonensis'

I would much prefer grafting over rooting, except when it's really easy to root (Thuja) or compatible rootstock is difficult to obtain, or in the case of Sciadopitys verticillata, seeds are hard to find and take forever to grow to the size needed to be used for grafting.

While I did classify my own statements about Dirr as a rant, it was actually an honest critique, and the thread you provided a link to was actually very useful. Tapla is very knowledgeable, and I am a huge fan of the 5-1-1 mix, so I trust his assessment about water rooting. I never know that. It was also interesting that he points out the fact that a rooting aid is really only necessary in the most hard to root species....which supports the foolishness of recommending it for one of the easiest to root species.

Even easy to root species have been shown to root more quickly, uniformly, and with more profuse root systems when hormone is used. This may be of no concern to a hobbyist that just cares if rooting occurs, period - but to a commercial propagator (one target audience of the book in question), that information is useful. Similar to the omission of water rooting information, which may be interesting to a casual propagator (but likely useless to a professional), the inclusion of rooting hormone recommendations for easy to root species may not be necessary for those that propagate on a small scale, but helpful to those for whom the benefits mentioned above can make a practical difference.

Yes: wholesale production nurseries are not going to be rooting aucuba in a glass on a kitchen windowsill.

Many subjects will form a callus and then sit there in the propagation setup indefinitely, without ever rooting - in my experience callusing of cuttings is seen as an undesirable alternative response to them making a nice wad of roots. In fact I personally have handled many cuttings of woody plants where roots came out of the stems only here and there, where callus tissue was not blocking them. So it it may even be desirable - or necessary - for the pine cuttings asked about here to be unstuck, have their calluses cut off with a suitably fine blade and started over again.

Starting a new thread on my experiment with the pines and callusing

Brandon, you’re well into this journey, but I was reading through the info the state extension site had on rooting cuttings, and Pinus mugo and Pinus strobus were the only pines listed.

https://content.ces.ncsu.edu/plant-propagation-by-stem-cuttings-instructions-for-the-home-gardener

(See table 1)

So, someone has done it successfully!