In the previous article, we discussed USDA hardiness zones, frost dates, selection of plants with regard to early, mid, and late season harvest times. We read about the various sizes of plants that one can purchase and begin growing. Moreover, we touched on the importance of learning the history of the soil where we are growing our plants. All of this is important to factor in when growing blueberries.
Again, I feel as though it is important to note that I’m not an expert in the propagation of blueberry bushes. However, my professional background is in the field of horticulture. During my studies in college, I remember that it took a significant amount of time to root woody cuttings (minimum 30-45 days, often 2-3 months). Additional research and reading about taking cuttings of blueberries suggested March / April as the proper time to take cuttings.
With that said, I decided to first take cuttings on March 22, approximately 8-9 weeks before the last frost. That day, I decided to take cuttings from the canes that were being thinned out. With each cane that was cut and “thinned” – cuttings were taken from the previous year’s growth. From the plants that needed to have canes thinned out, I took cuttings from the plants that appeared healthiest at the time.
Not really thinking ahead and planning, I proceeded to take my cuttings on Saturday afternoon with the intent of “re-cutting and sticking” the cuttings on Sunday morning. While in the field, I placed the cuttings in a plastic grocery bag and then placed it into the back of my Subaru overnight. The temperatures dropped below freezing for a couple of hours and it is likely that the cuttings froze over night as well. Whether this had anything to do with the success of the cuttings remains to be seen – however, it is worth mentioning and noting.
The following Sunday morning, about 18 hours after taking the cuttings, I began to “re-cut and stick” the cuttings. For sticking the cuttings, I decided to mix perlite, peat moss and some seedling mix. I was not very specific with the mix I created, but I would estimate I used about 40% perlite, 40% peat moss and 20% potting soil.
I decided to mix up the soil in a clear Rubbermaid tote and then simply stick the cuttings in the tote. The idea behind using the clear Rubbermaid tote was to create a greenhouse environment for the cuttings.
Below is a photo of the “final product” prior to actually sticking the cuttings.
After I had my soil prepared, I gathered my cuttings, a sharp knife (I used a simple grafting knife, but any sharp pocket knife will do), some rooting compound (I used Bonide rooting powder, purchased at Home Depot) and a pencil for poking holes into the soil.
The cuttings that I had taken were of varying size and lengths. These cuttings were taken from the older canes that were being removed during the thinning process. In order to record which bushes the cuttings were taken from, each plant where cuttings were selected from the thinned canes had white flagging tape tied to it. I decided to make my cuttings a more uniform length. I also decided to try varying lengths of cuttings.
Most of the cuttings I took were taken as “straight” cuttings, but some of them were also taken as what is known as “mallet” and “heel” cuttings. Mallet and heel cuttings are used for plants that might otherwise be more difficult to root. For the heel cutting, a small section of older wood is included at the base of the cutting. For the mallet cutting, an entire section of older stem wood is included.
Straight, Heel, and Mallet Cuts
Regardless of what types of cuttings you take, cuttings should generally consist of the past season’s growth. It is recommended that you avoid taking cuttings from plant material with flower buds, if possible. Typically, you want to remove any flowers and flower buds when preparing cuttings so the cutting’s energy can be used in producing new roots rather than flowers. Take cuttings from healthy, disease-free plants, preferably from the upper part of the plant.
After pruning my cuttings to a desirable length, I used the grafting knife to make a new, fresh, cut at an angle. Since these cuttings were from the previous day, I wanted a clean cut. Also, a sharp and thin blade would allow maximum exposure of the cambium and “green” wood prior to dipping into rooting compound.
At this point, I simply stuck the cuttings in the Rubbermaid tote. I didn’t really use any rhyme or reason when I stuck them in the tote, I just did it. My big pile of cuttings didn’t really amount to much and I was only able to fill up half of the Rubbermaid tote.
At this point, I kept the plants covered in the Rubbermaid tote with the lid on them. The plants were initially kept indoors for about three days, where they began to quickly bud out during the higher temperatures. I decided that the quick budding of the plants was something that I probably didn’t want, so I moved them to the mud room– which was probably in the 60s during the day and in the 40s at night, receiving indirect lighting through a window. Periodically, I would mist the plants with a spray bottle to make sure that the buds stayed tender and moist. For the next two weeks, that is about all that I did. After two weeks, the plants looked like this:
It was at this point where I took another batch of cuttings. The first cuttings were taken from the canes that were being thinned out. This time around, cuttings were taken from the healthiest plants. On each plant, especially the healthy plants, there was typically several shoots that grew rapidly, far above the rest of the plant. In the past, we would prune branches like this and “shape” the plant. In the nursery industry, this process is sometimes called “heading back.” This process removes the terminal bud and encourages growth and development of secondary buds, resulting in a fuller plant. It was typical to receive multiple cuttings from one pruning cut to the plant in the ground.
One other thing worth noting in the photo above is the praying mantis egg casing. Over the past 5 years, since we have stopped the industrial farming of grain (rotational corn, beans, wheat), we have seen a tremendous increase in the insect and earthworm population. This is an indicator of the overall health and healing of the landscape through the planting of diverse food crops.
Once the cuttings had been taken, I did not wait 24 hours, like I did the first time. I immediately returned home to make the cuttings a consistent length. Like the first time, I used the grafting knife to make a new, fresh, cut at an angle to allow maximum exposure of the cambium and “green” wood prior to dipping into rooting compound.
After dipping in the rooting compound, I stuck several cuttings into a second Rubbermaid tote, but this time around I stuck 4-5 cuttings closer together. The thought behind doing so was that as I “root pruned” the cuttings inside this second Rubbermaid tote, I would basically root prune each grouping of cuttings, effectively creating small “mini-plants” that would already have 4-5 canes to grow out.
Moreover, I wasn’t expecting 100% of the cuttings to take, and if I grouped my cuttings together in a cluster of 4-5, the likelihood of each grouping having several cuttings that took seemed higher, ultimately increasing the success rate of the cuttings taken during the second round. Below is a photo of how I arranged the clusters of cuttings in the second Rubbermaid tote used:
And finally, once all cuttings were taken, the Rubbermaid tote was sealed for about a week and a half.
What has taken place during that time?
(What initially began as a two-part piece is becoming a longer series. Thanks for reading and sticking with me during my experiment in cloning blueberries. Please leave comments and questions below and I’ll do my best to answer them for you.)