A question about how to grow big Arabidopsis plants in MS medium?

Hello researchers,

Sorry to bother you. My Arabidopsis have to grow on the MS medium
continuously. Now what I do is that after grown in the petri dish for about
one week, I transferred the seedlings into magenta box (sigma, V8505, W ×L
× H 77 mm × 77 mm × 97 mm) until to the end. But the problem is that the
space and nutrition of magenta box is limited, the plants grown there can't
give me the healthy siliques. If I transferred one more time into another
magenta box, the nutrition maybe enough, but I would damage the roots of
plants easily. Thus, do you guys have any experience to solve this problem?
Thanks!

Best,

Xi