I've tried giving them magnesium and Epsom salts but it hasn't really done any good. I give them Hollytone every month.

==>>> thats a lot of love.. considering you just planted them last fall ... i dont know which MIGHT have helped.. or what hurt them ... i tend to not add anything to disturbed roots after a transplant ... for at least a year ...if ever ....

i NEVER fert shrubs... though hollytone is about as inert as you can get ...

its a different story if the soil needs amending due to pH ... how did you determine your soil is acidic???

you didnt tell us how you planted... nor how you water ... be very descriptive ...

were these fall bargain plants?? .. if so.. who knows what hell they went thru before you got them ... bigbox or nursery???

ken

These were purchased last October'ish from Lowes. They were not bargain plants, they were full price and very full and dark green.

I planted them by mixing existing soil with some peat moss and mushroom compost. I ensured they were planted 1-2 inches above ground level.

Regarding watering, I usually hit them with a water hose every few days when there has been a stretch with no rain. I do not water the leaves! Note: I recently installed a soaker hose but it is not currently in use.

I was able to determine my PH by sending soil samples to my local Extension office. I sent a sample from around these Gardenias in April and it was acidic (~5.5).

I did not give them the iron and epsom until they started yellowing and dropping leaves in Spring, by reading the Internet and seeing that it could be a deficiency. Mind you that I have given the same Hollytone and Ironite to my Gardenias in the back and they're doing great.

I am at a loss. I have never seen a plant yellowing/dropping leaves at the same time it was growing new ones, unless it was just a few at the bottom. This one is basically all over the plant, new and old leaves.

Thanks for any suggestions you can provide.

Possibly nitrogen deficiency? I am seeing yellow vein chlorosis which apparently is a nitrogen deficiency. I looked back at the soil test results from extension office and they do not measure nitrogen in soil, only P and K. I give them ferts so I don't understand why this would be.