Soil anchor for plants

Is Spring time and is time to prepare for tomato planting season. Last year I had hard time anchoring the plants with strings to the soil and I thought about something to help me out fixing the string into the soil: a soil anchor.
The current design is suppose to be pushed into the soil, leaving the upper ring out and therefore allowing anchoring the sustaining plant string. Since this is suppose to be exposed outside, I have used PETG as a material due to its stronger mechanical characteristics, but I think PLA could be used as well.
The STL is placed horizontally, and if you need a stronger one, just scale it up as you need. Also the Sketchup file is attached, to change it if you need additional things on it.

Insert them under an angle into the soil (30-45) to maximize the anchor effect.