Japanese Spindle Tree Euonymus japonicus microphyllus Tom Thumb

Tom Thumb is the dwarf Japanese spindle, with tiny glossy dark green leaves packed onto a naturally tight rounded frame that stays low without being forced into shape. It shears cleanly and holds an edge, and unlike English box it takes heat, coastal wind and salt without browning off. That is why it turns up as the standard replacement for failed box: low edging along paths, parterres and knot gardens, a clipped skirt under standards, and small balls in pots either side of a step.

The box substitute, and where it still fails

Full sun to part shade, low to moderate water once established and moderate growth make it straightforward in most temperate and subtropical gardens, coastal or inland. The failure mode is drainage, and it is often the same problem that killed the box in the first place. In compacted soil, a bed that sits below the level of the lawn, or a strip that collects run-off from paving, plants yellow and die out in patches, and a patchy low hedge cannot be repaired invisibly. Fix the ground before planting: break up compaction, raise the bed where run-off collects, and set the crown level rather than sunk into a dish. For a low edge, plant about 25 to 30 cm apart in a single line and clip lightly from the first season so the plants knit into one continuous form rather than a row of buns. Give the row some air as well, since crowded hard against a wall in still humid conditions it will pick up powdery mildew. It also holds a shape in a container for years, though a potted plant needs watering and feeding on a schedule rather than by memory.

Choosing an edging plant

Green Rocket is the same species selected for the opposite purpose, a narrow upright screen, and it makes a poor low border because keeping it short means fighting its habit every year. Tom Thumb wants to be low, which is why it holds a crisp edge on two or three clips a season. Against Baby Bay the split is leaf and purpose, since Baby Bay carries a much larger aromatic leaf you can cook with and a looser texture, where Tom Thumb gives a fine, dense, formal line. Both euonymus selections tolerate a hard reduction and reshoot from wood, which is worth knowing if an edge has already been let go. More clipped options sit in hedges.

Shearing a low hedge to shape

Shear two or three times through the growing season, starting in spring once new growth has extended, and keep the last trim to early autumn so soft growth hardens before cold weather. Cut the sides with a slight batter, wider at the base than the top, so light reaches the bottom and the hedge does not go bare underneath. Feed in early spring with a controlled-release fertiliser, and again lightly after the first shear on poor soil. Watch the stems and leaf undersides for scale, and rake fallen clippings out of the row so they do not sit and rot against the crowns.

Choosing a size

This plant is available in 5 sizes, from 70mm up to 200mm, priced from $16.95 to $29.95 per plant. The size shown is the pot the plant arrives in, which is the rootball, not the height of the plant. These are younger plants, priced for planting in quantity, and they establish quickly once in the ground. Not sure which to choose? Read our guide to hedging plants for Australian conditions.