how much heat is enough for star ruby?

[Mark in Texas]

Adriano - Star Ruby is the exact Grapefruit tree that I have here in the desert of Palm Springs
California, and Millet is quite right - they adore heat, heat and more heat. I've got about 70-80 fruit
on my 10 year old tree right now - should be ready by mid December.  And let me tell you my friend,
It is by FAR the best grapefruit I have ever eaten - like sunshine with a bit of attitude (the acid I suppose)

 

Gary

It's in a corner of the yard with lots of other plants around so hard to get a good full shot of it.  It's about 15 ft X 15 ft. Much of the fruit is hidden but here it is:

If you like Star Ruby, you'll love the irridated sport from the Ruby even more - Rio Red.   Here's the history on it:
http://www.yaac.net/riored.html

Rio Red on sour orange rootstock grown in clay soil is really hard to beat regarding tree and fruit quality.

Mark

[MangoFang]

Yes, Mark in  Texas, I'd love to try Rio Red!  I've heard of them and think I've seen little 3 gallon
plants at Home Depot if I'm not mistaken.....but now I've got no room with that large tree I have....well, not just that one but also the 20+ mango trees I've got...

Gary

[Millet]

Most any citrus grown on Sour Orange root stock produces a great tasting fruit.  (Provided the tristeza virus is not in your area). - Millet

[Yorgos]

Millet, I am still confused about the heat hours.  Here in Houston, TX March thru November (assuming every hour is above 55, which is doubtful for some # of hours in March and November), you only have max 6,600 hours total (275 days x 24 hrs)!  An entire year only has 8,760 hours total (365 days x 24 hours)! So even in tropical climes it would take more than a year for grapefruit to ripen. That doesnt seem right. Can you 'splain it to me?

[Millet]

Yorgus, it is not the amount of heat hours, rather it is the amount of heat unites.  Going back I see that I mistakenly used the word hours in one of my posts instead of unites, I corrected that post. I apologize for my error.   As far as time from bloom to maturity, a grapefruit generally takes about 9 months, more or less depending on the trees location.- Millet

[adriano2]

my star ruby is now blooming. Is this unusual for grapefruit to bloom this late?

[Yorgos]

Thanks for the clarification Millet.  I went out and did some research and developed a spreadsheet. So, in Houston, Texas, if a grapefruit tree bloomed in mid-March a tree would have attained the magical 11,000 Units by early Sept. 
However, the fruit is still green in Sept and won't color up until December or so. Since flavor peaks in Feb. how does reaching the 11,000 DHU mark in September play into that?
 

[Millet]

A good number of people are not crazy about commercial grapefruit, mainly because they are pick early, at or near the 11,000 heat unit time period.  Of course commercial growers want to harvest as soon as possible for economic reasons. The 11,000 heat unites is assumed to be acceptable for harvest. This measure was set some times back.  In recent times many new varieties, especially reds, have come into existence. I am not sure what the heat unit number is for each individual cultivar. However, it is also known that the longer a grapefruit hangs on the tree, the the better the quality becomes.   Of all the people that I personally know, the one person with the highest level of intelligence on the science concerning the production of  citrus, Dr. Malcolm Manners PhD,  (Florida Southern University) once told me that grapefruit left hanging on the tree until March produces the most fantastic tasting grapefruit possible.  He further stated that of all the different grapefruit cultivars, the white fleshed Marsh grapefruit is the best of the best (at least in his estimation.) - Millet

[Mark in Texas]

Thanks for the clarification Millet.  I went out and did some research and developed a spreadsheet. So, in Houston, Texas, if a grapefruit tree bloomed in mid-March a tree would have attained the magical 11,000 Units by early Sept. 
However, the fruit is still green in Sept and won't color up until December or so. Since flavor peaks in Feb. how does reaching the 11,000 DHU mark in September play into that?
 

I wouldn't give it much thought, just do it.  I had excellent citrus while living in Corpus Christi which has the same clime as yours.  Citrus was on sour orange, same high pH "Victoria black clay" soil as yours.  My Rio Red was delicious, every year.  They do best with high summer heat and fairly cold winters, even standing cold into the low 20's with no damage.  Of course that Rio Red had a trunk girth of 10" too, and it was planted on the north side of the house.  After thought was that was a bad move....it loved it.

Temps held in the mid to upper 20's for a few days.  Fruit was fine.

Rio Red, Xmas 2004:



Orlando tangelo, same Xmas:

[Yorgos]

Not acummulating may heat units that day!  What fantastic pictures. Ive always run out and picked all my citrus before a hard freeze.  I guess I wont be doing that anymore. 
We rarely get snow here on the upper Guf coast but usually get a few days when the temps dip down to the mid-upper twenties every winter.

[Mark in Texas]

Yep, kissed oh so sweetly by some of that good ol southern snow.

ahhhhhhhhhhh........