Some trees are more prone to alternate bearing (fruit every other year) you can thin out the crop when the fruit sets to help prevent that. It's more common in mandarin trees, is that actually what this tree is? Or is it an actual orange tree like a Valencia, or navel, or something similar to that? Looks like a really nice tree.

Evan

Thanks for your reply, Evan. Yes, it's an actual orange tree. The fruit is medium sized, very sweet and juicy, and doesn't have any pits. The skin isn't real thick.

As Evan wrote your tree may not be setting a large crop of fruit every year because it may be an alternate bearing tree. When a citrus tree that tends to be alternate bearing sets a heavy crop (the on year), it uses up a lot of its stored reserves. The following year (the off year) is a recovery year. Yields can also fluctuate markedly from year to year even in regular bearing cultivars. This variability is associated primarily with climatic factors. Heat spells during the fruit set and fruitlet drop period are particularly troublesome. Many commercial growers foliar spray their trees with a urea fertilizer spray 2 months before expected flowering which greatly aids a citrus tree in setting and retaining fruit. I spray my trees with urea, and sometimes with potassium nitrate, in the first part of January, it works well helping the tree to set a good bloom.

Evan and Imelda have given you good advice. Definitely thin the fruit, if your tree really sets heavily, but wait until the fruit is golf-ball sized, so you know what has already dropped when fruit is pea-sized. Also, be sure to not allow your ripe fruit to set on the tree too overly long, as that can also cause a citrus tree to to alternate bear. Valencia oranges tend to alternate bear. Moro oranges as well. Washington Navel oranges can also be forced to alternate bear if circumstances are such (too heavy fruit set, leaving ripe fruit on too long, and climate factors as Imelda mentioned), as well as irregular watering or fertilizing. So, besides thinning a very heavy fruit set and not leaving ripe fruit on too long, be sure to water regularly, and fertilize regularly.

Patty S.

Proper fertilizing, water and compost tea if you like.

Thanks for all the great tips. That's good to know about the alternate bearing. I had no idea there was such a thing! It does make sense though and explains why there was so much the first year and hardly anything the second. Plus, we had just moved in, so the previous owners probably took much better care of it than we did.

Does anyone have any recommendations for a fertilizer that I could use on both the lemon and orange tree? And how often do you water/fertilize? The person who trimmed the tree last summer said to water about 5 feet away from the trunk. That only leaves a couple areas I could do this as the tree isn't too far away from the house on one side and the neighbor's driveway on the other.

kmas, it is true that watering directly on the trunk of a citrus tree is not a good practice , but staying 5-feet distant from the trunk is a bit extreme. Staying away about 1-foot would certainly be enough.

kmas, you would want to water at the drip line and a bit beyond. That's where the feeder roots reside. Hard to know what that drip line might have been, since the tree has been trimmed, but 5' would not be unusual for the age of the tree. I would attempt to water at least 3' out if possible. The drip line is certainly beyond 1' with the age of this tree. You can set up micro sprinkler emitters that point outward from the trunk at 12 3 6 and 9 o'clock. Or, at the least two points. For fertilizer, apply at the drip line. I would use a citrus fertilizer as it will have more N in proportion to P and K, and it should have micronutrients as well. Several good options out there. You can get Vigoro Citrus & Avocado fertilizer at the big box stores.

Patty S.

I don't like to hear that the Moro Orange tends to alternate fruiting. Is this the same with the Midnight Valencia? We got 4 new trees last year in 5 gallon containers. The Moros each had a few oranges. The valencia didn't have any, so I'm hoping for blossoms this year. So far none have appeared, but my other mature trees are loaded with blossoms. Sigh.

@Patty, I'm glad I'm not the only one using Vigoro. It is the only citrus fertilizer I've seen at Home Depot which has trace elements that citrus need. Unfortunately, it's not an organic option. But the price is just right!

Don't worry about it not being organic. All inorganic fertilizer compounds are converted to organic compounds, which plant roots can then absorb. You're saving yourself a fair amount of money with which to spend on other things. Like a new citrus tree :-)

Patty S.

Suzi, they "tend" to alternate bearing. I have one Moro that consistently alternate bears, and my other one not so much. All Valencias have a tendency to alternate bear, so just provide optimal conditions and it should be too noticeable. And, sometimes it takes a season or two for trees to start producing. I have a very, very vigorous Smith Red Valencia that just doesn't want to bloom much, yet. I got two fruits off of it this season. Still no significant blooms this season, so hoping next season it will bloom well for me.

Patty S.

As a general rule, standard practically seedless cultivars of orange, grapefruit, and lemon are regular bearers. Alternation, however, is almost a rule with many of the so called easy peeling types (C. reticulate, C. unshiu & hybrids, and early Satsuma. Valencia orange in cool areas of coastal California, and Shamauti oranges under semi arid conditions.