Skimmia is rather fussy about its growing conditions - needs shade, a rich acidic soil and adequate water. Insufficient quantities of any of these items can result in yellow, unhealthy foliage and/or mites. Planting close to a concrete foundation or along a walkway/driveway can affect soil acidity and this in turn affects how the plant absorbs nutrients and usually results in chlorosis or yellowing.

However, the above looks more like bleaching out/sunburn than anything else. How much sun is this plant in?

Thank you for your response. The plants are on the eastern side of our house and get about three hours of early morning sun prior to that side of the house becoming shaded for the rest of the day. So you are probably correct about too much sun being the problem. When I was deciding what to plant there, I was advised that skimmia could handle some morning sun and they seemed to do so for awhile, but they haven't thrived and it's the ones on the southern most end of the row that are in the sun the longest each day that are having the most difficulty, so I will move them to all to a shadier location. Any ideas for an evergreen shrub that can tolerate a mixed bag of morning sun and mid-to-late day shade?

Skimmia needs more shade. I'd say open North exposure is good, with adequate moisture. Too much dryness and mites are a problem -- especially if under an eave. Too much sun and they scald.

If you can tell us your zone and whether deer are an issue, we can probably give better ideas for plant options. Also, how high it can grow and if you're willing to prune. If you're in Rhode Island (?), you're probably what, a zone 6?
Unfortunately broad-leafed evergreen selection is not as good in 6 as in 7 and warmer.

There might be a sarcocca that is hardy up there. They also will bronze with too much sun, but are a lot more forgiving.

Not sure if Chinzan azalea is hardy there (Gumpo types)? Or Hoogendorn Holly (I. crenata), Softtouch Holly (I. crenata).

Maybe just a bed of pachysandra? Or maybe dwarf English boxwood.

Euonymus 'Gold Splash' (very difficult to find though and deer love it).

I am on the coast in RI in Zone 7a and we do have a deer problem. I've been thinking that pachysandra may be the answer although I wouldn't mind having something higher between 2 and 3 feet. I appreciate your other suggestions and will look into those.

Many thanks.

Another might be Rozannie aucuba. It stays smaller. Also, if your soil is VERY WELL draining -- like sandy, you might even give Daphne odora a go. I've killed several here, but our soil is very clayish.

What can I do if I have this plant but it is very large and in the sunny area and turning yellow? I can't transplant it because it is just too huge.