Yes, this can be common, but only a few leaves here and there.

Does the very new growth that also accompanies the flowers look abnormal, sor of bumpy, wavy, just not smooth and straight?

Spider mites can cause massive leaf drop if not caught and so can roots that are not happy with the mix.

May I ask why you are using a acidic fertilizer?
Are you loosing any branches or twigs too?

Mike

My little Sweet Olive plant has been dropping leaves while blooming and putting out new leaves so it might just be normal for this plant.
Do you have a moisture meter? I'm wondering if perhaps your soil might be too moist and not fast draining enough.

-Robert

Mike, sorry I put in acid fertilizer for my gardenia. For my osmanthus, I used the slow-release type regular fertilizer.

I have not seen much new growth in the past two month and the few new leaves are still very small. But the whole plants have been looking healthy. And both being flowering suggests they are, right?

Robert, the last time I watered them was 2 weeks ago so overwatering is probably not the issue. I do not have a moisture meter. What I do is primitive: I just stick a bamboo grill skewer into the container and leave it there for 5 minutes or so. If it feels dryish, then i water the plants. It has been working good for me on other plants.

I have attached a photo of my osmanthus. To the left is the one dropping leaves, all from lower part of the stems. The upper leaves look fine to me. And new flowers are still emerging here and there. So maybe this is normal, I hope.

Do you know that commercial potting mediums are composed of peat moss and very little of anything else. Your addition of even more peat has probably created a muck. It's not surprising that a plant might have problems.

I am very new to the forum and have been doing gardening in own way. I have been reading a lot on the forums here and just found out Al's gritty mix. So I will wait till spring and repot my osmanthus. Thanks for your responses.

Hi Jaywoods!

I would choose Al's 5:1:1 mix. I've been using Miracle-Gro's Orchid Potting Mix for the times when I'm too lazy to mix up a batch of 5:1:1. It does have more peat than the 5:1:1 mix but it still has a lot of pine bark fines and seems to drain fairly quickly.

-Robert