weird problem with blood oranges

[Lesli]

I have a small (dwarf) Moro blood orange tree. It is in a large molasses tub in good compost rich soil. It looks lovely. Last year it had 9 fairly large oranges on it that were all just turning yellowish early winter. I know blood oranges are usually ripe around February. So I am thinking that they are trucking along just about right. Well we were due some super hard freezes (for us anyway) and so I moved it into a shed that had several florescent lights going, probably 24/7. But the building is only corrugated tin so it gets pretty cold, but not freezing which I thought would be best. Well it seemed quite happy and after about March I still had pale yellow/greenish oranges. So I waited, Figured I messed them up taking them inside. I was looking for that rosy color that they are supposed to get because they are blood oranges, Well, after all threat of freezing weather was over I put them outside probably in March. It bloomed and now has about 8 new little oranges on it. But all the old oranges are still on it and they got greener after I put them outside!! Well this is July in Texas, they are still on the tree and while some are turning slightly yellow/orange/green, one or two are still fairly green and hanging on very well. What is going on? I pulled one off and while I don't have any "blood" it is orange in the inside and sweet. I was planning on making a small batch of orange marmalade, guess I will go ahead and do it. Just never saw this before. I had lemons (giant grubs were in the pot and girdled the tree and killed it) that ripened ok. Should I just leave them outside this winter if it does not freeze to badly? I am thinking of planting in the ground but hate to put them over the farm when we are not living there raccoons will probably take my fruit, but hate to plant it here if we are going to move to the farm... That pot is heavy and hard to move around, boys are complaining...

Lesli

[marseydoats]

My dad made my mom some extra heavy duty plant platforms out of a furniture dolly. That way she and I could move them around on the patio and in the basement. When it was time for them to go outside, he slid them up on a hand truck. Maybe you could try that until you decide if you're going to move.

[catherine]

I have several blood oranges in pots, myself. We've gotten some coloration from them, but not tons. When we lived in California, I remember reading that blood oranges colored better there than in the Houston, Texas area, due to the climate differences...dry vs. humid, as I recall. I looked up the topic online, and I've copied a selection of comments on the topic, below. I also found a couple of references to how oranges will regreen in spring. My dad, who grew up on a citrus orchard in the Rio Grande Valley always said that Valencia oranges weren't really sweet until Christmas, and still loved them come spring. My Houston humidity is probably the worst of the problem, keeping day/night temps relatively similar, as opposed to the wider fluctuations you'll have near drier San Antonio. You should have at better chance of good coloration than I will. Hope all of that helps. One way or another, enjoy your tree and it's sweet fruit! ;D

The red pigmentation varies with climate and can be intense when blood oranges are grown in regions with large diurnal temperature fluctuations (hot days, cold nights).

The literature citing cool weather for coloring is bogus, the red pigment in the flesh is a function of heat units. The pigment on the skin is a function of cold nights in the Winter, e.g. in the tropics all citrus are mostly green, although there are exceptions.

Blood oranges cultivated in the United States are in season from December to March (Texas), and from November to May (California). While the tree will grow and bear fruit in Florida, the "Mediterranean" temperature variation between day and night seems to be necessary to develop the distinctive red color[6] – blood oranges grown in Florida often have little to no red pigmentation.


Each of the U.S. blood orange cultivars is visually distinctive. Tarocco tends to be slightly elongated, the Moro round, and the Sanguinelli somewhat egg shaped. Each type differs in climate preference, size and flavor. Temperature, amount of light and the variety seem to affect coloration and intensity of blood oranges. In Texas, for example, varieties tend to have less pigmentation and even the highly colored types do not develop the dark-red coloration for which the blood oranges are noted. Moro, Sanguinelli and Jaffa are usually seedless and develop the most intense color, while Ruby is lightly flecked at best, with 10 to 15 seeds.

Coastal southern California fruit ripens from February to May, November to February in the low-elevation desert and February to May in the northern coastal region. Gulf Coast and Texas fruit ripens December to March. In Florida, Moros begin to mature in October. Usually Ruby and Moro are considered mid-season, while Sanguinelli is late season. Mid-season oranges mature in late November to early January, and late season oranges mature in February or March.

Most American oranges come from Florida and California. Due to differences in soil and climate, Florida and California oranges—even those of the same variety—vary in color, texture, and juiciness. Florida oranges are thin-skinned, very juicy, and easy to squeeze. California oranges are best for eating. They usually have full orange color (due to a drier climate with cooler nights), thicker skin, and less juice.
The mutation that produced the blood orange’s ruby red color arose in the 17th century in Sicily.

These same pigments, activated by chill nights, make deciduous trees burst into orange and red flame in fall.

Blood oranges hail from Sicily, where they appeared as a fortuitous mutation several centuries ago. Our most common varieties are the Tarocco, Sanguinello and Moro, the last being the youngest and most fiercely purple.

While most blood oranges are still grown in Italy – where they dominate the orange business – and Spain, in the United States they grow in California (November through May) and Texas (December through March), where day/night temperature differences mimic the Mediterranean climate that best suits the fruit and allows it to develop its distinctive color.

The fruits on the trees in spring will regreen, lose their orange color and turn green.

During the warm seasons, while the oranges are still in the tree, their skin reabsorbs chlorophyll from the leaves, which causes them to turn green again - this begins at the stem. At this point, the oranges are actually ready, sweet and juicy.