Does grapefruit do okay on its own roots, or is it better to graft? I have a few Rio Star seedlings started from supermarket fruit. They're pencil thickness now, and I'm wondering if I should plant them out on their own roots or graft them to either rough lemon or sour orange. Both of those rootstocks are proven in my area.

My interest is primarily the health of the plant, but also fruit quality. My climate is tropical wet/dry, temperatures moderated by ocean (no salt problem, though). Soil is clay-loam.

One option I am considering is grafting it onto sour orange (sweeter fruit than rough lemon) and letting the original Rio Star seedling re-sprout as a backup. Your thoughts?

Thanks,
John

Grapefruit do fine on their own roots. I have two Ruby reds I grew from seed, both started fruiting in the fifth year. Both produce loads of excellent fruit each year.

While grapefruit on their own roots can make a fine tree, there are several reasons to choose to graft them instead:
1. By placing the scion on a selected rootstock, you can gain several more degrees of cold hardiness over an own-root tree.
2. Grapefruit roots and lower trunks are highly susceptible to phytophthora root rot and foot rot (crown rot). By grafting rather high on a resistant rootstock, you can greatly reduce the likelihood of that disease.
3. Some rootstocks (sour orange, Swingle, Poncirus) will cause a grapefruit to produce higher quality fruit -- sweeter and more richly flavored.
4. Some rootstocks will give some size control, important in grapefruit since it is inherently such a large-growing citrus tree.

They do get rather large on their own roots.

The fruit from my tress are much tastier than the fruit from the store. Maybe because the fruit is picked long before it reaches the store.

Or because you actually leave it on the tree until it's truly mature, Laaz! But the very highest quality grapefruit are those grown in a hot, humid climate, slightly nitrogen-deficient, and left to full maturity on the tree, on Sour Orange rootstock. The three places that vie for top quality are the Texas coast, the Indian River area of Florida, and Cuba.

Thanks Malcolm. I may graft one to sour orange to test. We are definitely hot & humid enough. Between living here & where I lived in Pompano Beach, it feels a whole lot hotter here in the summer than in Pompano. Probably because there was always a breeze blowing there. Here it is dead air with extreme humidity.

A few shots from today.

Good luck, Laaz. Surely your summers are hot enough, but your winters may hold you back. Most Florida grapefruit is not really fully mature until after Christmas, with some varieties (Marsh seedless, e.g.) more like April for peak quality.

I had one of my pink seedless grapefruit blow off about four days ago.

I decided to try it (even though it had been laying on my deck since it fell) and was surprised that it wasn't too bad. It wasn't as juicy as I would have liked and since it was not full size it had thicker cell membranes. They flavor was still very good though. Interior color was excellent. Exterior had a blush of color at about 50%.

It would be nice if grapefruit growers held their fruit on the tree until after Christmas, or until April before they were marketed. If so, I believe more people would like supermarket grapefruit. Presently what is marketed in the stores is certainly OK, but regrettably not at peak quality. I grow Star Ruby grapefruit in a warm greenhouse in Colorado, but unfortunately keeping the greenhouse heated at high levels throughout the winter months would cost way to much money. I try to keep the night temperatures during the winter at 50F (10C). Even at this, the cost is approximately $4,000.00 dollars per year to heat it as is. Still the grapefruit turns out quite acceptable. I get to eat it all, as my wife does not like grapefruit. - Millet

I also take a cholesterol medicine (Pravastatin), but I still eat grapefruit. We eat breakfast at home Monday through Friday, but go out for breakfast on the weekends, then I always order a side of that wonderful tasting meat --- bacon. - Millet

From last December.

Dr. Manners, don't forget our S. California deserts for delicious grapefruit. I can actually grow exceptional grapefruits if I stick varieties like Rio Red. I leave my fruit on the tree until February, and even in my tree's first year in the ground with me, they were delicious. Of course, we're really more Oroblanco/Melogold territory here, but my Rio Red was so good, I bought a second one. I have a question for you, however: You are so, so right about grapefruit (and especially pummelos) being very susceptible to phytothphora. That was what was doing in my pummelos/pummelo hybrids due to being on Troyer/Carizzo. What rootstock would you suggest for oranges and mandarins, as well as grapefruits/pummelos that will be more resistant to phytophthora as well as provide reasonably sized trees producing good fruit? Right now, I'm using C35 or C32 (if I can get it), and for my Cocktail pummelo hybrid, Volkameriana (since the Cocktail tends to be a small tree to start with). And Millet, if you're worried about your statin, ask your doctor if you can change to Pravacol or Crestor, it is not contraindicated with grapefruits and pummelos.