themi:
Are you in a tropical zone on the California coast? I am Not overly familiar with the "Sunset Zones" cold/heat rainfall etc.On a more general theme...
The 1 gallon plants(S.greggii) are going to dry out more frequently than the 5 gallon (S.microphylla "Hot lips").
Next what soil type are they planted in ie clay,Rock and clay mix, garden soil what is your soil composed of??? This is going to be a shock (in my 30 years of gardening) to much organic material can be detrimental to woody plants.Vegetables no problem some perennials compost is fine.Any way we will wait for your response so there is more information on your soil compostion, weather etc..
Where I live your temperature would be considered a cold front. I grow both S.microphylla "Hot lips" and a many different forms of S.greggii also.
Sincerely
Art

I'm in Sunset zone 23 / Fallbrook. Are you in 24, meaning coastal and more overcast weather lately? I grow alot of salvia and I've still been planting lately even with the heat, probably more sun than you get. I never amend the soil. If I were going to add anything, it would be perlite or gravel to help with drainage. I do mulch. I wonder about the plants being at the bottom of a slope...is, or will this slope be planted, watered, meaning is all of the water going to run to the bottom of the slope on the salvias? I wouldn't assume the plants need more water without actually checking the moisture of the soil with my hands.

Hi and thanks for the replies!

My zip code is 92865. That is considered USDA zone 10. It is inland with no coastal influence The soil (aside from the organic matter my gardener added) is basically decomposed granite and sand. So very well draining.

The slope is fully planted. Penstamon at the top because that area is partial shade. The penstamon is doing great. Also there is lavender Provence and some sweet pea shrubs sprinkled throughout and those are all doing splendidly as well. It's just the one gallon greggi that is struggling.

Sounds like it could be some transplant shock, shade netting might have been more useful than extra water. Even if the greggi seems to fail, it can stump sprout, if the roots survive. Moderate water, leave it alone and hope for the best is what I would do.

Yes on the netting. I have a bunch of 6 ft, cheapo $7 umbrellas from Harbor Freight that I use to stick into the ground to shade plants that have been planted at the worst of times.

For your zip code, you should actually be Sunset Zone 22....

Ok great - thanks for the advice. I will hope this is just transplant stress and keep my fingers crossed. I wasn't expecting significant growth right now, I just don't want them to die!

Oh and thanks for the correction on my Sunset zone!!

I just wanted to add a comment. I grow a lot of sal. greggii types and these are in a garden that had already been amended many times since I have clay soil. So when I planted these I added some sand to the mix knowing the greggii are native to desert areas and are a more xeric plant.

When I water my other plants which require more water I may give these a little water but not much. In fact I might not water these every time that I do the others.