Dahlia Stem Problem

Question

The stems on my dahlias are disentgrating a couple of inches below the ground. There’s green starts below the spot.

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Answer 1

There appears to be quite a bit of algae growth. This tells me that the soil remains too wet and compact for plants to grow comfortably. You may have to amend the area, or try and grow these in container. Here are some articles that will help:

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-moisture-in-plants.htm

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/test-soil-for-pests-and-diseases.htm

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/making-sure-soil-drains-well.htm