I live on the upper Gulf coast, just inland of Galveston Bay. For the past three weeks my improved meyer lemon tree, and two satsuma orange trees have been in glorious bloom. The bees went crazy, and all three trees were covered with little tiny fruit.
Over the past week disaster has struck. Something has eaten or caused to fall off almost every tiny fruit from the lemon tree. It appears that leaves are also being stripped off. I've been watching this closely, and one day a branch will appear healthy, and the next its fruit and some leaves will be gone. While there are some leaves on the ground, and some old blossoms, those numbers are small compared to what is missing from the tree.
I might assume that the culprits are caterpillars, but I don't see any pests of any kind on the tree. I'm stumped.
I have included a picture of a branch that was previously bearing fruit and leaves, and which is now mostly stripped. Over the past several days this appears to have started happening to the orange trees as well.
What is happening, and what can I do to limit the damage to the orange trees before I lose that crop as well?
Here are more pictures. This one is of the lemon tree. Note that there are still many leaves, though some are missing. The fruit from these branches is almost completely gone.
Here is the base of one of the orange trees. As you can see, there is a good deal of dropped fruit on the ground, but almost no orange leaves. (Those leaves in the picture are from mulch from last fall.)
This last picture is from the orange tree as well. Many leaves are still on the branches, but a lot of fruit has dropped.
Maybe it's just the trees dropping their fruit, but I am certain that many leaves are gone as well. These trees otherwise seem quite healthy, and in past years I have not seen them lose this much fruit. I should also mention that the orange trees do have a lot of fruit still on the branches. I want to keep it that way, which is why I am so concerned about the loss of fruit.
Finally, I will also mention that my young grapefruit tree (3 years old), which is nearby, initially had 30 or so immature fruit on it (which I was going to pick off), but has dropped all but one. That was the first tree that exhibited this behavior.
Stormy asked for picture of the entire trees. Here are the two orange trees.
OK, I originally posted this in the spring, and now its falls (mid-October). I answered my own question, suggesting that it was a spring cold spell that caused the budding fruit to drop.
Now that it is fall, I have to say that I was a complete worry wart. We've never had a crop so prolific as this. In a normal year we'd be picking fruit in late November. This year, however, we've been eating oranges, small ones, to be exact, since September - every day!
So here is what's going one. The trees are laden with fruit. In August we noticed that the trees where dropping green fruit. One day I peeled a green orange that had fallen, and found it to be edible. Since that day, we've pretty much been having oranges. It's hard to describe how unusual this is.
Nowadays, we are picking to help the tree with the weight, mostly picking the ones that are beginning to show some signs of color. Nonetheless, we are eating oranges every night, which is great. The fruit is continuing to mature, and at some point we expect the fruit to be normal (large, orange, and easy to peal). So far, they have been small and mostly green, but even so the pulp has been sweet and more than ready to be eaten. By late November, I expect the remaining fruit to be large and delicious.
What a change! What I thought was a major loss of fruit turned out to be an abundance that I could not imagine.
Thank you for everyone who lent an opinion to the original post. It turns that our loss of blossoms was not a tragedy. What remained burdened our trees to the point that I worried about the weight of fruit, and we've been harvesting steadily in order to help the trees along their journey towards winter respite.
Take a look: