Bitter Orange in Las Vegas

Q. I was so happy to see an article you recently wrote in the RJ concerning bitter orange trees.  I have one that was here when I bought my house 16 years ago.  It was in a patio pot at that time and I had it replanted, along with a Meyer Lemon, in the “alley” between my house and my neighbor.

Bitter orange tree planted in Las Vegas.

My lemon has been giving me fruit for the past approximately 8 years and about 30-35 lemons.  My orange tree has always produced flowers, but no fruit up until 2 years ago. I got about 25 nice sized oranges.  Last year I got flowers but Not A SINGLE fruit. Is this a tree that may “skip” a year in fruit production?  I have done nothing to these trees except fertilize with Arizona Best’s Citrus fertilizer Valentine’s Day, Memorial Day and Labor Day.

Myers lemon (not readers) planted in Las Vegas.

A. “Skipping” a year is called “alternate bearing” and occurs, usually, with older varieties of fruit trees like some almonds and apricots. Bitter orange, like most oranges, produces the majority of its flowers in the early spring. This is the same time we experience freezing weather. Your fruit loss could be because of freezes.

Did You See Flowers?

It is important to ask, “Are you sure you saw flowers in the spring and no fruit?” That’s an important consideration. If you did then it was a failure to set fruit. That is either because no pollinators were present (bees and other pollinators like flies and moths) or it froze several times in a row in the early spring.

No Flowers

If you did not see flowers in the spring, then it was because it never flowered. That could be because of some hard pruning that was done, and the tree is recovering, or too much fertilizer was applied too often. This is true particularly of high doses of nitrogen fertilizer such as ammonium sulfate (21-0-0). In either case, the tree grew so vigorously that it never flowered!

Fertilizer Applications

Normally one fertilizer application is all that is necessary, or two at the most. If two is applied, then apply half of your normal fertilizer application in the early spring and half right after harvest. If harvest is close to your early spring application time then apply fertilizer to citrus just before it gets hot in the early summer. Avoid making fertilizer applications when it is hot. In the case of citrus that might freeze, avoid fertilizer applications after July.

Tree Surrounded by Rock Mulch

Some citrus okay with rock mulch.

I noticed that the tree is surrounded by rock mulch. Yet it has good color. Citrus of all types don’t usually like rock mulch all that much. The first thing to go is dark  to medium green color in the leaves when it gets unhealthy. That’s why I was surprised with your tree. Maybe your choice of fertilizer helps.

Some citrus not okay with rock mulch. Use amended soil when planting and citrus fertilizer every year.

Citrus are from southeast Asia and China. They prefer to grow in soils with a higher organic content than most soils covered in rock. Along with your fertilizer application try raking back the rock at least three feet all around the tree and applying compost or wood chips to the top of the soil. Water it in and rake the rock back on top of it after it is watered. Do this about every year or every other year at the least. I think your bitter orange will like this type of soil better than soil covered in rock.

Pomello on our farm in the Philippines.