If Walker had not been afraid of falling asleep while he meditated. It was actually expected since he had used so much mana and stressed his mind greatly. Fortunately, everyone on the ship had seen him sit down and start meditating before he had fallen asleep. It was fair to let him be after what he and Alma just did.
The elves rushed to Alma after they had seen her also sit down. He had been pushed to her limits and beyond. No normal person would have as much mana as they had just used. The single reason they had been able to was that she had barely used her own mana to make the plants grow. It had all been natural mana from the storm.
The fact that this was the case allowed Alma to reach a higher usage of a skill she was not able to use all the time. She had felt the minute changes in the wild bull kelp as it had grown, been destroyed, and recovered. All these things pushed her mind to a new way of guiding both it, and other plants in the future.