Containmus Magicus

You take your 5000 gp ruby and inscribe runes on to it and then inscribe the runes onto the 20 platinum pieces, as you then tie them all together into a ball using the ball of twine and you chuck the ball of twine, 20 pp, and a 5000 gp ruby inscribed with runs as it evaporated the components once it touches the target and ensnares the target.

You select an object, city, creature, etc., and stop it's growth, ne it how the DM sees fit to stop growth of the target.