I’ve done one of these before, with a different plant and a different camera.
This one is with the Canon 40D and an interval timer, which means the frames can be exported in a High Def format, rather than the 4:3 aspect standard def version I managed a few years ago.
One frame at 25fps is equivalent to One shot a minute for just under 24 hours.
(i.e. one second = 25 minutes).
One battery of the 40D was able to last just over 12 hours on a full charge, which was quite good! Mounting the camera backwards on my tripod allowed me to (very carefully) change the battery during the timelapse period. All images were shot as large JPEG, rather than RAW, to ensure I could get them (1435 images) on a single 8Gb card. Using a desk lamp I was able to continue shoot throughout the night for the whole period.