| Gravetye Estate William Robinson Gravetye Charity | 254.67 ha | | — |
| Wakehurst Royal Botanic Gardens, Kew | 121.95 ha | | — |
| Newtimber Hill National Trust | 103.83 ha | | — |
| Wolstonbury Hill | 87.82 ha | | — |
| Borde Hill | 57.34 ha | | — |
| Bedelands Farm Local Nature Reserve | 45.2 ha | | — |
| Loder Valley Nature Reserve Royal Botanic Gardens, Kew | 33.18 ha | | — |
| Blunts Wood and Paiges Wood and Meadows Local Nature Reserve | 30.34 ha | | — |
| Malthouse Lane Meadows | 21.65 ha | | — |
| Hammonds Ridge | 16.84 ha | | — |
| Nightingale Lane Meadows Nature Conservation Site | 16.15 ha | | — |
| Cuckfield Park | 13.06 ha | | — |
| Saint Hill Manor | 12.74 ha | | — |
| Batchelors Farm Nature Conservation Site | 12.71 ha | | — |
| Round Hill | 11.28 ha | | — |
| NT Nymans Gardens National Trust | 10.45 ha | | — |
| High Beeches Garden | 9.0 ha | | — |
| Railway Lands | 8.62 ha | | — |
| Lindfield Common | 6.68 ha | | — |
| National Trust Standen House and Garden National Trust | 6.04 ha | | — |
| Victoria Park | 5.95 ha | | — |
| Beech Hurst | 5.93 ha | | — |
| Adastra Park | 5.89 ha | | — |
| East Court | 5.86 ha | | — |
| Paxhill | 5.79 ha | | — |
| Church Covert The Woodland Trust | 5.44 ha | | — |
| Worth Way Nature Park | 4.85 ha | | — |
| Pangdean Lane Meadows | 4.84 ha | | — |
| St John's Park | 4.77 ha | | — |
| Woodgate Park | 4.65 ha | | — |
| Gravetye Manor Gardens | 3.48 ha | | — |
| Brooklands Park | 3.19 ha | | — |
| Mount Noddy Recreation Ground | 3.01 ha | | — |
| East Court Mid Sussex District Council | 2.95 ha | | — |
| Worth Way Country Park | 2.86 ha | | — |
| West Park Nature Reserve | 2.44 ha | | — |
| Nymans Wild Garden | 2.36 ha | | — |
| Cuckfield Recreation Ground | 2.34 ha | | — |
| Woodgate Green | 1.99 ha | | — |
| Grassmere Meadow | 1.71 ha | | — |
| Henry Burt Wood | 1.69 ha | | — |
| Lingfield Road Recreation | 1.57 ha | | — |
| Horsefield Green | 1.35 ha | | — |
| Sunte Park | 1.06 ha | | — |
| Marle Place Park | 1.02 ha | | — |
| West End Farm Recreation Ground | 1.01 ha | | — |
| Quiet Garden | 0.87 ha | | — |
| Bermondsey Huts Camp Site Worth Abbey Projects Ltd | 0.68 ha | | — |
| Grovelands Open Space Mid Sussex District Council | 0.61 ha | | — |
| War Memorial Garden East Grinstead Town Council | 0.32 ha | | — |
| Millenium Garden East Grinstead Town Council | — | | — |