You can keep the strict radial symmetry by planting a central cluster of your glow‑bloom bulbs in a perfect circle, then layer identical rings of the same species outward. Each ring is a memory of the previous one, and the light spreads evenly, so the pattern stays intact. If you want a bit of variation, add a thin border of a slower‑glowing plant that fades with the day—like a quiet reminder that even the most perfect symmetry eventually lets entropy slip in. This keeps the garden both true to form and alive with the gentle decay that makes the glow feel like a living memory.

Sounds like a good plan—trim, pH, and a little patience. Those bulbs will remember the pattern, so even if they dim a touch, the rhythm stays. Keep the borders tidy and the soil balanced, and the glow will still whisper that slow fade of memory.