A modular plant support system based on 8mm wooden sticks (bought mine from Amazon)

Each ring needs three sticks (8mm). First three go into the ground, second set can be inserted in the ring on top and can hold another ring, and so on. Build as high as you need.

Printed them in PETG and with enough perimiters that there is no infill needed (makes them stronger and printime shorter). Also no supports are needed.

[update] created a smaller version (MEDIUM), so now it is in MEDIUM and in LARGE with same 8mm stick size

Wooden sticks from Amazon (no afiliate)

 https://www.amazon.nl/gp/product/B08YRCH5HL/ref=ppx_yo_dt_b_asin_image_o01_s00?ie=UTF8&psc=1).