Would adding sulfur around Canadian hemlocks help them to green up if in alkaline soil?
You’re talking about trying to acidify alkaline soil. It’s not something that can be done easily, or quickly. Yes, sulfur will help drop the Ph – use the amounts recomended on the package. And you’ll be doing it several times a years, nearly forever. It’s a long process, not a quick battle. Mulching with pine needle mulch, or pinebark, will also, slowly, over time, add a lower ph material to the soil. As far as “greening up” a hemlock – the condition that does them in around here is being planted in a soggy place. They like consistent moisture – but they need well-drained soil – with a capital W. Which is partly why they hate clay…it’s not only alkaline, but worse, it doesn’t drain well. If you hemlock is in a well-drained spot, but the soil’s alkaine, then it’s probably that the ph is too high for the tree to metabolize the iron that’s in the soil. Adding sulfur will help, over time, but a fast method would be to add chelated, water-soluable iron, into the soil. Lots of products for
