Great container plantings almost always follow one framework: thriller, filler, spiller. Learn it once and every future combination becomes easier to compose.
The framework
- Thriller — the vertical anchor. Tall, upright, structural. Usually one plant, centred or off-centre.
- Filler — mid-height body plants that surround the thriller. Two to four plants, usually mounding or clumping.
- Spiller — trailing plants that break over the rim and soften the pot itself. One to three plants around the edge.
The ratio in a typical 45–60cm bowl: 1 thriller, 3 fillers, 3 spillers.
Sizing the framework
- Thriller height ≈ 1.5–2× pot height
- Filler height ≈ 0.5–0.8× pot height
- Spiller trail ≈ 0.5–1× pot height, cascading
A 50cm pot might carry: an 80cm phormium (thriller), 25–30cm heuchera (filler), and 40cm of trailing bacopa spilling over.
Ten combinations we return to
1. Mediterranean evergreen
- Thriller: Standard olive
- Filler: Lavender ×3
- Spiller: Trailing rosemary
- Notes: Full sun, sharp drainage, sparse watering. Almost indestructible once established.
2. Shade classic
- Thriller: Fatsia japonica
- Filler: Hardy fern ×2, Heuchera 'Palace Purple' ×2
- Spiller: English ivy
- Notes: North-facing terraces, side returns, under mature trees.
3. Formal doorstep
- Thriller: Standard bay
- Filler: Heuchera in a single colour ×4
- Spiller: Erigeron karvinskianus
- Notes: Timeless, low maintenance, works either side of a front door as a matched pair.
4. Grasses-led modern
- Thriller: Miscanthus 'Morning Light' or Stipa gigantea
- Filler: Carex ×3
- Spiller: Bacopa or Creeping Jenny
- Notes: Movement, transparency, autumn colour. Modern architectural gardens.
5. Cottage garden pot
- Thriller: Verbena bonariensis
- Filler: Salvia 'Amistad', Nepeta ×2
- Spiller: Trailing lobelia
- Notes: Pollinator magnet. Cut back in September for a second flush.
6. Tropical drama
- Thriller: Cordyline australis
- Filler: Canna 'Tropicanna', Colocasia ×2
- Spiller: Sweet potato vine 'Blackie'
- Notes: Half-hardy. Bring cannas and colocasia under cover in October.
7. Winter interest
- Thriller: Cornus 'Midwinter Fire'
- Filler: Skimmia japonica ×2, Heuchera 'Marmalade' ×2
- Spiller: Ivy variegated
- Notes: Structure and colour from October to March. Underrated container planting.
8. Minimal single-plant
- Thriller: One ornamental grass — Stipa tenuissima or Deschampsia
- Filler: None
- Spiller: None
- Notes: The pure-line composition. Pot must be beautiful; the plant is the punctuation.
9. Herbs for cooking
- Thriller: Rosemary upright
- Filler: Sage, thyme, oregano
- Spiller: Trailing thyme
- Notes: Sunny position by a kitchen door. Trim little and often.
10. Seasonal switcher
- Spring: Tulips + violas + trailing ivy
- Summer: Dahlia + petunia + trailing lobelia
- Autumn: Chrysanthemum + heuchera + ornamental cabbage
- Winter: Skimmia + cyclamen + trailing ivy
- Notes: One pot, four moods. The heuchera and ivy carry through; the hero plants swap.
Compost and feeding
- Peat-free multipurpose for annual displays
- 70% multipurpose + 30% John Innes No. 3 for permanent plantings
- Slow-release feed pellets in April; liquid tomato feed fortnightly for flowering annuals through summer
Watering rhythm
Container plantings dry out faster than borders. In summer:
- Small pots (under 30cm): daily
- Medium pots (30–60cm): every 2–3 days
- Large pots (60cm+): twice a week
Water thoroughly until it runs from the drainage hole — half-watering builds shallow roots that then dry out even faster.
Editing over time
Every planting composition needs pruning back roughly monthly through the growing season. Remove:
- Spent flowers
- Overreaching stems that unbalance the composition
- Filler plants that have crowded a thriller — cut back hard, they'll recover
Start with two or three of the combinations above, learn what they do across a full year, and the framework becomes second nature.
