In the previous article, we discussed the background behind our experiment in heirloom blueberry cuttings. In this article, we expand the series by describing the cuttings. As you will recall, we accidentally cut a 7-foot shoot from a bush while we were clearing it of vines and saplings back in February. Having had a successful round of cuttings from the same bushes years ago (despite having those cuttings all die later from unrelated neglect), we decided to turn this shoot into cuttings. Only about a foot or two of this shoot had significant bark, the rest being mostly green growth.
Using garden shears, we created three types of cuttings, as shown below:
The first type of cutting was the woody stalk. We didn’t expect this part to do well, and didn’t want to take up space in the cartons with it. But, we didn’t want to throw it out, either. We left this piece about a foot long.
The second type of cutting was the little branchy parts. These would make nice largish plants if we could get them to root. We had a lot of success with this type of cutting previously. These are also about a foot long. In some cases, branches from these were also cut if the overall branch would be too large.
The third type of cutting was about 2-3 inch pieces from the main part of the shoot. We wanted to have at least two bud nubbins (technical term) on each cutting. One of these would be the new live shoots, and the other would help create roots. In practice, we wound up with three nubbins on each small cutting. Since none of these had leaves, there was no need to trim anything else. We did cut off and discard some portions that seemed a little dry.
In all cases, we just cut straight across the shoot. Some sources say to make an angled cut to leave the xylem channels with a larger surface area, but this experimental technique we’re using depends on the cut end sitting more or less flat on the bottom of the rooting chambers.
Next, we soaked all these in our cuttings box. As mentioned in the previous article, this box is a six-quart plastic container (with lid), which we bought from Walmart for about a dollar. We removed the egg carton lid, and placed it upside down in the plastic box. We then test fit all the cuttings into the box. Since we’re going to be soaking them for a while, we wanted all the pieces to fit. You can see below that we had to do a lot of trimming to get everything to fit, so we created many more little cuttings to get the larger pieces down to size:
Next, we placed the small cuttings in the bottom of the box on the egg carton lid …
… and then covered them with a half-sheet of paper towel (the kind that is actually absorbent and not just shredded plastic). On top of that paper towel, we layered the larger cuttings:
Ideally, we would like to use rainwater for this, but we used reverse osmosis water instead. In general, for horticulture, we prefer to avoid tap water as the chlorination is more likely to kill the essential microbes.
We kept the cuttings soaking for about a week, mostly covered with the plastic box lid. On sunny days we would place the box outside to help kill fungus, and to heat the box up a bit. Keeping the box warm and humid, like a little greenhouse, helps open the crushed pores at the ends of the cuttings, as well as saturating the cuttings with water to prepare them for the rooting process. You could put a little liquid fertilizer in at this point, but we tend to go very light on fertilizer. At this stage, the goal isn’t to grow the cuttings, just to get them ready for the actual rooting step. We certainly don’t want to encourage rooting during the soaking stage. We also don’t use rooting hormones at any step in this experimental process.
In this article, we’ve described how we prepared the blueberry cuttings for rooting. In the next articles, we’ll talk about the rooting process itself.