is ericaceous compost ok for planting indoor gardenia?
I wish to pot a newly acquired gardenia plant.
Yes, since gardenias are classed as ericaceous plants, compost (potting soil) mixed for acid-lovers should work. Gardenias grow best in pH of 5.0 - 6.0, you may want to do a simple pH test now and then. This article has more tips on growing gardenias in pots: https://www.gardeningknowhow.com/ornamental/flowers/gardenia/growing-gardenias-indoors.htm