These are irises in the woodlot border - bunches that lost their labels. When they bloom, I'll be able to check old photos and identify them. Several of these clumps are beginning to push flower buds, most for the first time in three years. They went through my not being able to care for them, to randomly transplanting to the edge of the woodlot, to getting a little more attention in the past year. A lot of these are historic cultivars although some are modern.
Growth is rapid now. The fir bark mulched plants remain cleaner, much less leaf spot disease compared to those in bare soil.
Looking back through photos, the leaf spot has been present in most of the older photos, but the plants bloomed nicely anyway. I think I can also see it on the plants in my old photos of visits to Schreiners' Iris Gardens. So I think as long as it is limited, it won't hurt. But if the bark mulch really does decrease leaf spot, I will consider using more of that.
One thing that's interesting, is most of the irises I see around town have no problems with leaf spot disease. I don't know why. Most of those are also in borders with ground fir bark. Again, I wonder if that is protective?
I also wonder if the disease arrives on freshly purchased and planted rhizomes. Those seem like the most affected in my garden. The older, long-established clumps do not seem affected, or much less so.
The plan: buy a truckload of chopped fir bark this summer, and apply around each of the iris clumps. I use about an inch thick. I try not to cover the rhizomes per se, but I don't obsess over keeping them exposed.
It's hard to see in these photos, but these plants have several flower buds. Very promising.
