Specialty Gardening: Gardenias - when to fertilize? (time and plant indicators?), 1 by lamcarolyn

lamcarolyn wrote:
The picture is of my new house. It was taken before I moved in. I have made lots of changes, and I'll update if y'all like. :)

It's a bad picture, but those hedges out front are gardenias. (no idea what kind!)

The hedges to the left seem happy and healthy. They're a solid green mass, and they're doing great.

On the right, you can barely see them, but there are two plants. The first one is looking pretty straggly. I discovered last week that it's because every dog in the neighborhood pees on it. Now that I have new sod and I'm obviously taking care of my garden, I have high hopes that they'll stop.

The second one looks decent...but it has a few (maybe 5% of the plant) yellow leaves with green veins.

I've done my research, and apparently this means it needs iron. But the soil around the gardenias are a rich red iron clay -- which is probably why gardenias grow so happily in my neighborhood.

So my questions are:

1. How many of these yellow green-veined leaves do I need to see before I fertilize?

2. Should I do any maintenance fertilization? Before or after they've bloomed? (They've got some lovely buds right now, but no blooms.)

3. Is there anything I can do for my poor straggler? A local garden expert gave me glorified pepper spray for it, but that's only preventative....to keep dogs away from it, not to fix whatever pH problems they may have caused.

thanks for your help :)