Hello, I am in central London Ontario on sandy soil. Over the last three years all my five very established patches of Solomon’s seal have been dying off. They are scattered over different parts of the property. Some of the clumps have absolutely nothing done to them and are quite separate from the others. They come up looking healthy but at this point in the season most have gone yellow, look wilted and eventually just fall over. I can pick them out of the ground with no resistance and the ends are black and rotten. A couple of the ends have had tiny white worms in them but this is not the norm. No one in the area seems to have this problem. I have asked the London Master Gardeners but they could not give me any explanation. Can you help? Thank you, Alma
Thank you for contacting Toronto Master Gardeners.
Polygonatum biflorum, Solomon’s Seal, is hardy plant that thrives from zone 3 and is an understory plant. It should be in full shade and in well drained soil. Once established the plant can tolerate dryer soils and is a long lived plant that spreads by rhizomes.
Solomon’s Seal has no major issues with pests or disease. The only pest found in the literature is sawfly. The larvae usually show up on the leaves and eat away at the plant defoliating it. This does not sound like what you are describing with the small worms.
From the photo you have attached it does look like the base of the plant has rotted which suggests the bed or containers you are using are not draining well. Are the plants in an overly wet location? If the plants are in sun that will also stress them.
Take a look at the planting location and note how wet the soil is and how long it takes to drain after it rains. If the area is not the ideal environment for the plant you may want to dig up the rhizomes and put them in a new spot that is full shade and drains well.
The below link has further reading on Solomon’s Seal.
This link explains the sawfly and how it affects Solomen’s Seal.