Flowers To Use in Stone Planters

The council nursery have advised that, because of the limited soil depth and the dryness caused by the tree, planting in these stone planters needs to be simple, tough and realistic.

This page sets out a planting approach for a 125 cm x 125 cm stone planter with a tree in the middle. That means the planted space is smaller than it first appears, because a clear ring needs to be left around the trunk.

The best approach is not to overfill the planter. A restrained mix of drought-tolerant plants around the outer part of the bed will usually work better than trying to pack the whole planter densely.

What kind of planting suits this planter?

These planters are best treated as:

  • dry or fairly dry
  • sunny to lightly shaded
  • shallow and rooty
  • best planted around the outside rather than right up to the trunk

If the tree canopy is very dense, or the roots are especially strong, use fewer plants and concentrate them toward the outer edge.

Quick tree check

The exact tree matters less than the growing conditions.

  • Thorns present → likely hawthorn
  • Cherry-type bark, serrated leaves → likely ornamental cherry
  • Glossy oval leaves, small pear-like fruit → likely ornamental pear

Whatever the tree is, the safest assumption is that the planter will be drier and more root-filled than an ordinary flower bed.

Prep

  1. Hand-weed and remove litter.
  2. Expose the root flare and do not bury the trunk.
  3. Gently loosen only the top few centimetres of soil.
  4. Do not dig deeply near the trunk.
  5. Water once before planting so the soil is workable.

Soil refresh

For a planter of this size, top-dress and improve the upper layer rather than trying to re-make the whole bed.

Use roughly:

  • 25 litres peat-free compost
  • 25 litres loam-based compost
  • 10 litres grit or sharp sand
  • slow-release fertiliser at label rate

Mix this into the top layer only.

Finish with a mulch layer, but keep a clear space around the trunk.

Planting rules

  • Keep a 20–25 cm clear mulch ring around the trunk
  • Plant mainly in the outer half of the planter
  • Use fewer, tougher plants
  • Let the planting grow in over time rather than trying to fill every gap at once

Recommended planting palette

Best core plants for this planter

These are the strongest choices for a small, dry, sunny stone planter:

Use sparingly as feature plants

These are useful, but only use one of them as a stronger anchor plant:

Use only if the spot is slightly kinder

These are better on a slightly shadier or less harsh side of the planter, not in the driest central zone:

Bulbs

Bulbs can be tucked between the permanent plants in autumn.

Good options are:

How many plants to buy

For one 125 cm x 125 cm planter with a tree in the middle, a good guide is:

  • 4–5 edge plants
  • 3–4 filler plants
  • 1 anchor plant
  • 20–30 bulbs

That is enough for the planter to look cared for without becoming overcrowded.

Simple shopping list

A practical planting list for one planter would be:

  • 2 creeping thyme
  • 3 Mexican fleabane
  • 2 Nepeta
  • 1 sedum
  • 1 lamb’s ear or 1 perennial wallflower
  • 1 lavender or 1 santolina or 1 euonymus
  • 24–30 bulbs

Optional:

  • 1 campanula on a slightly kinder edge
  • 1 heuchera only if there is a slightly shadier, less dry side

Layout in minutes

  • Keep the 20–25 cm ring around the trunk clear
  • Put the thyme and fleabane around the edge
  • Place the fillers in small groups in the outer half of the planter
  • Add one anchor plant only
  • Tuck bulbs between the permanent plants
  • Finish with mulch, but keep it away from the trunk

Watering

After planting:

  • Water the whole planter well to settle it in

For the first 4–6 weeks:

  • water regularly in dry weather

After that:

  • water during dry spells
  • expect the outer plants to cope better than anything placed near the trunk

Water slowly and keep water off the trunk.

When to plant

Best times:

  • April to May
  • September to October

Bulbs:

  • September to November

Maintenance

Spring

  • tidy winter damage
  • top up mulch
  • divide crowded plants if needed

Summer

  • weed lightly
  • deadhead where useful
  • water in dry spells

Autumn

  • plant bulbs
  • replace any failures
  • divide and replant if clumps are too large

All year

  • keep mulch and soil away from the trunk
  • remove litter
  • do not let the planting become too dense

Final note

This is a small feature planter, not a large border.

The aim is to have a planting scheme that is:

  • attractive
  • realistic
  • pollinator-friendly
  • easy for volunteers to maintain
  • tough enough to cope with dry conditions and tree roots

In practice, fewer plants, planted well, will usually do better than too many plants crowded together.

The planting scheme for the 125 cm x 125 cm stone planters includes a central tree with a clear mulch ring, surrounded by a mix of Mexican fleabane, creeping thyme, catmint, sedum, lamb’s ear, and perennial wallflower.