a Moro Blood Orange story...
2013: Bought it at home depot, and after this picture I repotted it into a rootmaker container that Millet gave me. Soil is 5:5:1 mix of cedar mulch/peat/perlite
2014: Looking fantastic. Huge root and canopy growth, nice dark green all around. After taking this picture I cleaned the soil off the roots and repotted it into a slightly larger diameter rootmaker container. The tree was nearly 6ft tall including container.
2015: Looks about the same as last year, no significant new growth. Some of the oldest leaves are getting very yellow and overall color less green than last year. Somethere around this time I had stopped using liquid fertilizer and switched to only Osmocote Plus because with so many trees it was a huge burden to mix many gallons of fertilizer-water. Right before taking this picture I had repotted it into a 4" wider rootmaker pot, which has a diameter of 19",
however, I did not clean the old soil off I just filled in around it. Over the winter those yellow areas all dropped their leaves and the same twigs died back. The newer growth stuck around. It bloomed but none of the fruit held.
2016: Here it is today during repotting. The canopy is smaller than it was 2 years ago, though the rootball is as large as ever and filled a 19" diameter rootmaker container. You can't see in the picture but it does have new white root tips around the perimeter. It had put out substantial new growth in spring but it still is overall smaller than its peak. It looks much lighter green than it once did. I regularly refresh the Osmocote and when repotting I still saw plenty of unspent pellets floating around. This time when I repotted I cleaned all the old soil out extensively. I planted it in the same 19" wide container but this time I planted it "higher" as after cleaning it had some roots hanging down that looked like they could begin to fill the lower third of the container. I've seen 15ft tall trees in containers this size so I'm skeptical that it really needs a wider one.
So, I'm disappointed that it isn't thriving. I'm not yet
worried at this point because the roots look great. When I repotted today the soil was mostly mud as the cedar chips had almost completely decomposed. I think not cleaning the old soil off last year was a big mistake. However, I thought that if soil aeration was limiting growth it would show up as rotted roots of which I found none. So, I'm stumped as to what the problem is here.... insufficient fertilizer or insufficient aeration? Other possibility is insufficient light, as the nearby apple trees at my old place were starting to grow in and shade it. At my new place all my trees get direct sunlight the entire day.
My new greenhouse won't be ready until next year at least so all trees have to stay in containers until then, and I can't switch to sand/gritty mix because it is too heavy to carry.