Garden Plot: Effectiveness

https://preview.redd.it/ee323qyledze1.png?width=1338&format=png&auto=webp&s=59289190c0b784d8a5fdfa5fb1e5696c551f5bc2

I started playing Lego Fornite when it released and started using the "Garden Plot" at some point.

My oldest garden plots seem to be WAY more effective than new ones I build.
I can havest multiple berries from one plot, instead of just one from new ones even though they all have a full stack (now even up to 80) of seeds in it.

How can I make my garden plots as effective as my old ones?
I dont know what I did differently then.
Does it even matter how many seeds are in there, though it makes sense that more seeds yield more fruits.