I have had very little. I have tried to propagate Bluecrop and Northland by using softwood cuttings but have not had great success. Here is what I did:
Just as the tips of the plants were turning a bit rigid, I took my cuttings. These cuttings I then stripped off all but the top 2 or 4 leaves and if the leaves were large, I cut them in half to reduce the leaves surface area. I dipped the stem in rooting hormone then placed them in a peat/perlite mix under my misting system.
Over the course of the summer I checked them for roots. I was a bit surprised to find that they did not form roots as readily as other softwood cuttings I do. In fact, they did not seem to be doing anything. They retained their leaves but refused to form roots, even after being under the mist for months.
At the end of the summer I again took a look to see if roots were forming. 2 out of the 15 cuttings I stuck had a single root about 1/2 inch long. Not very good rooting percentage when I am used to 90% rooting success with my other softwood cuttings.
So what went wrong?
Well, I am not sure but because it was the first year rooting softwood cuttings after I had a water softener installed, I am assuming that had a big impact. It definitely had an impact on my other cuttings. I do not have access to a Ph meter so I do not know what the Ph of my water is now.
The spring and summer were extremely wet which may have reduced the temperatures around the cuttings too much as well as reduce the amount of available sunshine.
I may have also took the cuttings a bit early.
My propagation references recommend early to mid summer and I may have jumped the gun a little. I live very near the top of a large hill in a very hilly area of southern Maine and although just 6 miles away spring may have arrived, I will usually still have a minimum of 2 more weeks before my plants even think spring is here. So hilly, I can see Mt. Washington on a clear day!
Dirr’s Manual of Woody Landscape Plants states the cuttings should be collected in June and treated with 1000 ppm of IBA, then placed in a peat/perlite mix, but his Reference Manual of Woody Plant Propagation says May cuttings with decreased success in late summer. It also says to use 8000 ppm IBA-talc + thiram or 4000 ppm naphthaleneacetamide and place the cuttings in peat/perlite under mist. Hmmm, a little confusing.
A third book I use on propagation states that hardwood cuttings are the best means of propagation, but this particular book was written well before intermittent mist was discovered. It says to place cuttings taken from one year old shoots during late winter or early spring and plant them in a box frame. Attention to water and shade as well as humidity is needed, but the cuttings should root in 6-8 weeks.
What am I going to do?
- Bypass the water softener to start so my cuttings use un-softened water
- Pay closer attention to the time of year the softwood cuttings are taken and be sure to not take them too early
- Try a few hardwood cuttings in a nearing frame as my older book suggests
How do you propagate your blueberries?
For more information on blueberry propagation:
Propagation of the high-bush blueberry by softwood cuttings (Bulletin / Massachusetts Agricultural Experiment Station)
Propagation studies with the southern blueberry (Bulletin / Mississippi Agricultural Experiment Station)
The propagation of highbush blueberries by softwood cuttings (IVT mededeling)
Propagating blueberries from hardwood cuttings (Circular / New Jersey Agricultural Experiment Station)