Hello, Here in Florida we have three Duncan grapefruit trees that are around 40' tall in our back yard and If the fruit are not removed the next years crop will be deminished greatly. Duncan are a white fleshed fruit and are fairly sweet. Cold snaps during the winter months will increase sugar levels in all grapefruit. As with most citrus, grapefruit should be harvested during winter and spring. Our tree will hold fruit for 5-6 months. We generally leave a few on the tree as a kind storage for later. Most the fruit should be picked off to stimulate next years fruit set. So in a nut shell when you see flower buds forming pick the fruit but preferably before. We core the center making them into a cup and drink them right out of the fruit. I have posted diretions below.
Here is a link to the university of FLORIDA'S AG. DEPT. GRAPEFRUIT
Hope this helps.
Duncan grapefruit tree.
Start by peeling off the outer yellow layer of skin
Be careful to leave the white layer this will allow the fruit to be squeezed without spliting.
Cut the top off the grapefruit
Next core the center out without poking the knife through the outer skin.
Once the center is cored angle you knife to cut through the membrane of the fruit segmants.
Squeeze, drink and Enjoy!!
As you can see by all the peelings on the ground Angela and I set here peeling lots of oranges and grapefruit and let me tell you these Duncan grapefruit are sweet.