I purchased three Thimbleberry plants about 5 or 6 years ago. Lost one due to planting in a not so well drained area. I transplanted to a shady slope under a large pine tree. The plants look healthy and have spread out but have not gotten very tall or produced any berries to speak of. They have lots of flows and appear to be ready to fruit but have only produced maybe 5 berries over the last 3 years or so. This summer I installed a temporary shade sale to prevent some strong and hot sun from covering the plants every morning until about noon. The plants appear to suddenly be growing higher, time will tell. Lots of flowers as always but still look like they will not produce any fruit. Do you think the pine tree soil is the issue? Thanks in advance. Fritz
They should be able to handle the acidic soil under the tree, and with extra nutrients to supplement what the tree steals, they can do just fine. I would bet that if you tested your soil, there will be nitrogen levels like you would expect, but lower phosphorus, and potentially potassium. After testing the soil, you should be able to see what it is lacking. These articles will help:
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/ornamental/shrubs/thimbleberry/thimbleberry-plant-info.htm