It won’t be long before gardenias are bursting into their glorious fragrant bloom, and there are a few things you can do right now to ensure you get a great display. The first is feeding and watering. Gardenias commonly experience bud drop when they’re dry and undernourished, so if you haven’t had rain in a while, give their roots a deep soaking, then spread around some fertiliser – something like a citrus food is ideal – and water it in. If the mulch around the plants is getting thin, throw down a layer about 5cm deep to help hold in that moisture, and follow up with a regular drink once a week if needed throughout the flowering period.
Sap-sucking scale insects are a serious pest in gardenias, and they are active now. They park themselves on spring growth and celebrate the steady flow of sap. These guys, with their sugary excretions, are responsible for the sooty mould you often see on gardenia leaves. Don’t let their feeding frenzy spoil your display. If you see little scale insects on gardenia stems, or on the tops and undersides of the leaves, smother them with a spray of diluted horticultural oil, then follow up in another week or two. That should slow them down. No scale, no mould!