Propagating
hybrid poplar trees with hardwood cuttings

Patience must be exercised when waiting for the last leaf to drop before you can start taking cuttings.

It took me quite a few years to piece all the information below together. I made plenty of mistakes and killed lots of trees with trial and error experiments, but, here it is, the whole enchilada, nothing left to chance. Just follow these instructions and you will have no problem making and using cuttings from not only poplars but many other trees.

The reason hybrid poplars are propagated using cuttings is simple. It is the only way they can be propagated. Poplars do not have flowers or produce seeds which is the most common way to reproduce trees. Using hardwood cuttings (from dormant trees) is also the easiest way to work with poplar cuttings and the most convenient and reliable.

A word of caution: Some trees are very difficult to propagate from cuttings. Among them are the Quaking Aspen, Valley Forge Elm and the Yellow poplar (tulip tree) to name a few. For information on how to propagate other trees you could get a propagation book, the one I use is the "Plant Propagation" published by the American Horticultural Society. No matter how or when you take the cuttings, the information here will help you in keeping them alive.

First of all, for hardwood cuttings, you must wait for the right time of the year. As soon as the last leaf falls off the tree, you can start taking cuttings. I don't do it until February and I have my reasons for doing it that late. More on that, later.

You take cuttings from only 1-year old branches. How do you know they are 1 year old? Look for buds along the surface of the branch, they will be about 1.5 to 2 inches apart. If the branch does not have buds, it is not a 1-year old branch and will not work for this project.

Cutting length:

Cuttings can be as short as 2 buds or as long as 8 feet. If you want to sell them, then your customer will decide what size he wants or just make them 9" long which is the standard size.

The best way to plant a cutting is to make a hole as deep as the cutting is long, that is, if you have a 9 inch long cutting, the hole whould be 9 inches deep and once the cutting is planted only 1/2 inch of it will show above the ground. This assures that only one bud will be exposed to the light and will grow.

I have been experimenting with long (6 ft. long) cuttings, and planting them 1ft. deep. They will grow and remain alive only as long as you remove most of the lower buds when the cutting starts growing. If you fail to remove the side branches, all of them will try to grow at the same time, and in the meantime under the soil there is a solitary root pumping nutrients to 15 branches. The root is not able to keep up with the demand and the tree will not be as strong as it could be.

I take cuttings every year from a lot of different trees, and I have used 2 bud cuttings for about 6 years with great success. My cuttings are from 1/8" to 5/16" in diameter and 2.5 to 5 inches in length.

The Taking!

This is what you do. Wait for a cold day in February, and armed with a chainsaw cut the chosen tree down, You can leave 4" showing, the tree will regenerate and not only that, it will coppice. Move the down tree to where you can work with it in the open. Switch to garden shears and start removing branches from the tree. Take only parts of the branches that are 1 inch or thinner. You can make long cuttings (up to 8 ft., or just short 2 bud cuttings. The rest of the tree is discarded.

The long cuttings can be planted right away, I plant 3 to 6 ft. long cuttings in 1 gallon containers. Shorter branches can be taken indoors for further processing. Short cuttings should not be any thicker than 5/16" . Start at the end of the branch, and remove the first (top) bud. Do not use that, it is not reliable. The cut you just made should be very close to the next bud. Now turn the branch around and look into the end of it. It should be light green. If it is not, you are working with a dead branch. Do not forget to do this... every time, you don't want to mix dead cuttings with live cuttings.

The next cut is below the second bud. When you make that second cut, make sure the next cutting will also have the top bud 1/4" or less from the top. Continuing this way, every time you make a cut it will be a new cutting.

Dead branches are common. When you have done a few thousand cuttings you will feel if you have a dead branch in your hand, you will not even make that first cut.

The taking of cuttings can go very fast once you know what you are doing. Sometimes the buds are very close to each other, in that case I leave the cuttings 3 buds long but never longer than 5 inches because I use 5" long plastic bags to store them. You can do a few hundred cuttings in one seating, when done, put them in plastic bags, seal them and they go in the freezer, you don't want them to come out of dormancy, they would die. This is the way I take my cuttings, you can make them longer and thicker if you want, they all would work but in my case I have very limited space and the 2 bud cuttings work fine for me.

For 9 inch cuttings, choose branches that are 5/16 to 1.25 inches in diameter. It is harder to cut them because you are working with much heavier stock and must use a branch trimmer but the look is the same, top bud 1/4" from the top. Measure 9 inches and cut. Now you must fix the end so the next cutting will have the first bud 1/4" from the end.

South of the border.
If you are in the southern states, the trees will not drop their leaves, at least, not all of them, in that case, take cuttings in February which is when the weather is the coldest, and store them the same way it is described below. You may have to remove the leaves by hand, if they come off easily, if not, rather than injuring the branch, cut the leaves off being careful not to damage the buds.

Storing
You will need a regular freezer to store your cuttings until you are ready to use them. I use a 14 ft. upright with shelves. I also use clear plastic shoe boxes with labels (dollar store) which is where I keep the cuttings in alphabetical sequence.

You will also need a freezer temperature controller to keep the temperature very close to 28 degrees. You can buy this item from many web sites, it is made by Johnson Controls and it is the model 9025. Any attempts to keep cuttings without controlling the temperature will result in great losses. Regular freezers are set to work at 10 degrees and you can adjust that a couple of degrees but never up to 28 which is nearly the freezing point. Here is a link to a web site that sells that control, look for the "Freezer Tamer" $59.95, here is a picture of it.

Hooking up this control is a no-brainer. Put the sensor (the silver thing with the coiled wire) inside the freezer. Use Duck or Duct tape to keep it from moving, secure it to a wall on the inside of the freezer, and also tape the wire, now plug the control in a 110 outlet, and plug the freezer on the back of the control's plug. You are almost done. Now adjust the control to 28 degrees. The control will not keep it exactly at 28 degrees, temperature will fluctuate about 2 degrees above and two below but that will do the job.

Keeping the cuttings alive:

The reason I take cuttings late in the season is because they don't stay viable for too long. You have about 6 months in which you can sell the cuttings and they will be viable. If I take them in November, I have only until May before they start going bad. If I take them in February, I can sell cuttings until the beginning of July.

Another consideration to keep in mind is the fact that the freezer will remove moisture from the cuttings and, unless properly protected they will dehydrate. That is the reason all cuttings being stored in the freezer are in a sealed plastic bag. This will keep them from drying up. I store most of my my 2 bud cuttings in 3x5 bags and I store well over 7,000 of them in my freezer.

With this information you can now take cuttings and keep them alive until ready to plant them or ship. When you ship them, keep in mind that the cuttings will start coming out of dormancy as soon as you take them out of the freezer, and you have only a few days in which to plant them, so ship them either next day or 2 day delivery. I use only Priority mail which delivers most of the time in 2 days. When I ship to overseas, I always use air mail.

As an interesting fact, in March 2005 we shipped a few thousand cuttings to Afghanistan, where the authorities quickly lost track of them. Over 3 weeks later, they were located and my customer sent me photos of the cuttings. The buds had grown inside the boxes in the dark, over 2 inches. Very carefully the cuttings were taken out of the boxes, planted, and most of those cuttings have since been dug out and sold as 7 or 8 ft. trees.

Another approach

Every year, I instruct my helpers to prepare 1000 bags with soil and place them in the large trays outside. I wait until the beginning of March and then we take 1000 cuttings of OP-367, plant them in the bags and water them well. There may be ice, snow and cold temperatures during March but the cuttings just sit there, all buds still closed. Sometime in Early April all the cuttings start to grow at the same time.- that's mother nature for you - and out of the 1000 cuttings we plant, probably 980 trees make it I sell them during the summer at $7.00 each, I sell 20 inch tall trees. When we plant, every cutting will get treated with a rooting hormone.

Try this sometime

. About 10 years ago, I took 400 cuttings of OP-367 in November, right after the trees went dormant, I carefully prepared a small plot outside about 8x3 ft. and covered with black plastic. I tucked the edges of the plastic with a spade all the way around.

I remember it was sunny but cold. I proceeded to poke the cuttings thru the plastic, deep so only the top of the cuttings were visible. I put them about 4" apart. You can picture a grown man sticking sticks in the ground in a very cold day in November. Well, I got all 400 planted and then I forgot them... until about 2 months later, I went to check them. Some of the cuttings were laying on top of the plastic. I figured squirrels had pulled them out. I put them back in their holes. A month later, I went again and saw the same thing, then I figured the constant freezing and thawing was pushing the cuttings up and out of the ground. I continued putting them in their holes.

By mid April, some of the cuttings started leafing out. By the end of the month, I had 400 very small trees and by the end of May, I had to dig them out with a shovel because their roots were all tangled up. I lost some, but I was able to transplant the rest. By the end of the year, some of them were over 10 ft. tall.

This is only to show you what you can do with cuttings. If you are growing for your own use, you don't need a freezer, just take them and plant them right way. They will grow. I use a freezer because I sell cuttings until the end of June.

If you have any questions about something I missed, please e-mail me

Frank Gomez