How to treat Japanese Buxus hedge plants turning brown?

Akshaybun

Hello lovely people, need desperate assistance with my Japanese buxus plants.
Per attached images, I've realised few of the plants are turning brown crisp where, the entire plant turns brown over a period of time.
Fyi - I water the plants once in 2-3 days. These are planted next to colorbond fence and mulched with pine bark.
Also, the soil is clay type.

Appreciate if you can please advise on below-
1. How can I save the plants?

2. How often should these be watered?

3. Any soil or plant fertilisers to be used and when?

4. Do I need to water plants twice a day and then alternate days especially in summer ?

5. Do I need to insulate the colorbond fence with something?

MitchellMc

Hi @Akshaybun,

Your Japanese buxus definitely do not look very happy, and the biggest concern from your description is the clay‑based soil. Most plants, including buxus, struggle in heavy clay because it holds water tightly and can leave the roots sitting in a constant pool of moisture, which eventually causes browning and die‑off. This also makes watering frequency very hard to determine, because the surface may appear dry while the root zone is still saturated. Fertilisers will not fix this problem, because it is unlikely to be a nutrient deficiency; it is far more likely to be a drainage issue.

The best approach right now is to only water when the top 10 cm of soil has begun to dry out. Dig your finger or a small trowel into the soil to check, and avoid watering on a schedule until you know how quickly the soil drains. If the decline continues, you may eventually need to replace both the soil and some plants, ideally using a raised bed or a trench filled with a premium garden mix so the roots can breathe properly. You do not need to water twice a day in summer, and doing so in clay soil would likely make things worse. Insulating the Colorbond fence is generally unnecessary; the heat radiating from it can stress plants a little, but healthy buxus can tolerate this as long as the soil drains well. Right now the focus should be on managing moisture and considering long‑term soil improvement or plant replacement if the clay proves too restrictive.

Please let me know if you have any questions.

Mitchell