I would guess that the best time to prune the tree would be after any chance of frost is over, but before the tree blooms. Otherwise, you risk cutting off the young fruit and will have year of few or no grapefruit. Most citrus matures in November-December.
after picking the fruit
what is the best time of the year to prune liveoaks
I've read to prune after flowering.
Prune Escallonia in early Spring .
winter
Yes you can prune your goldfish plant. It is best to do it during it's dormant(non-blooming) time.
Many believed that the best time to prune Raspberry bushes are in the late winter or early spring. The plant should be over a foot before trying to prune the bush.
It is best to prune mums in early spring and early summer to make them bushier and with more flowers in fall.
grapefruit
It is not recommended to prune chrysanthemums in early winter. It is best to prune them in spring and remove all the dead parts. However, you should water them if the weather is above freezing.
Wait until Valentine's Day and then prune it down to a foot or so tall. Then, feed and water it.
In Spring after flowering if pruning is necessary.
east