The cuttings must be planted at least a foot deep, soon after you receive them. The soil in February is frozen and there is no way for you to dig anything, then all holes must be dug when the weather is nice.
Make the holes 12+" deep and 1-2 inches in diameter. You can use a small hole post digger, or an auger.
Before you plant, you should remove most of the buds from them. There is a bud every 1 to 2 inches. Leave a few buds at the very top of the cutting. Scratch the lower foot of the cutting with a blade and dust it with Hormodin 1 (Included). Carefully put the cutting in the hole and backfill. If the hole is small enough the cutting will be snug and no other support will be needed, otherewise you will need more support like a 6 ft. bamboo cane driven in the ground parallell with the cutting and attached to the cutting with cable tiesl , When you plant this cutting, all the buds on it will start growing at the same time. Also roots will be formed at the bottom of the cutting. This root system is very small at the beginning, and inadequate for all the branches that are growing topside and the tree may die if too many branches are being formed at the same time.
Does this method work? This is what I did in 2008: My neighbor came to let me know that 3 of my weeping willows were in his property. He had called surveyors and they were putting little pink flags all over the property line. 3 of my willows were 2 ft. inside his property. That meant I had to do something. I told my neighbor I would move them when they were dormant. I then dug 3 holes about 2 ft. deep and 3 inches in diameter( in my property of course). I covered the holes with a tile and stuck a bamboo cane in the ground so I could find them in case they were covered with snow when I was going to use them.
I waited until the middle of February, got my chainsaw and cut all 3 trees down. I kept the chainsaw as close as possible to the ground. Then I removed all the branches from the trees so that at the end all I had was 3 long sticks. I applied rooting hormone to the bottoms of them and dropped them in the holes. I packed soil back and had to support them so they would not move at all, I drove some pipes in the ground parallel to the "sticks" and used cable ties to keep them from moving or swaying. I watered them well.
The trees started making a lot of growth by early April. Many branches were removed, specially any that grew below 8 ft. All others on top were thinned so there were only about 4 branches. As the trees grew, I allowed more branches to develop and today, (Jan 2010) the branches reached the ground. All 3 trees are alive and growing. I did this with a weeping willow but you can also do it with most poplars. Below is a photo of one of my willows. This particular tree is over 12 ft. tall today.
This, by far, is the most practical, and most economical way to plant hybrid poplar trees. If you are interested in ordering some of these 6 ft.cuttings, please go to the Cuttings page and scroll down to the bottom of the page.