Guides · Soil
What to plant in chalky or limestone soil
How to know you have it: White flecks in the spade, it fizzes with vinegar, thin over rock, and the pH is above 7.5.
Chalk is shallow, alkaline and free-draining, and it is the soil where plant labels lie most often. Anything acid-loving — camellia, rhododendron, most heathers, blue hydrangea — will yellow between the veins and sulk for years before it dies. Chlorosis is not a feeding problem you can spray away; the iron is there, the plant just cannot take it up at that pH.
The good news is that chalk downland is one of the richest plant communities in Europe, and its plants are all garden plants: viburnum, buxus, Sesleria, Salvia nemorosa, achillea, thyme, euphorbia. They want exactly what chalk gives them — sharp drainage and no winter wet.
The one real constraint is depth. Where soil sits 20 cm over solid rock, a large tree is a lie: plant a small one, or raise the bed. Amelanchier and field maple both cope; a forest tree does not.
The four rules
- 01Do not fight the pH. Plant what likes lime instead of feeding what does not.
- 02Check depth to rock with a crowbar before you choose a tree.
- 03Compost and mulch generously: chalk soils are thin on organic matter.
- 04Yellowing new leaves with green veins means the wrong plant, not a missing fertiliser.
What we plant in chalky soil
These are the species our own plant database will draw from for a site on chalky soil — 3 trees, 2 hedging species, 5 shrubs, 2 grasses, 6 perennials. Prices are French retail nursery prices per plant, 2026, at the pot size given.
| Species | Type | Height | Spacing | Price | Why it belongs |
|---|---|---|---|---|---|
| Field mapleAcer campestre · Érable champêtre | tree | 8,00 m | 6,00 m | 165 € | The reliable small native canopy for heavy ground; takes clay and wind without sulking. |
| OliveOlea europaea · Olivier | tree | 5,00 m | 5,00 m | 240 € | Needs sharp drainage; on clay it is planted on a raised gravel mound, never in a sump. |
| Sweet cherryPrunus avium · Cerisier | tree | 7,00 m | 6,00 m | 78 € | Prune only in summer: a winter cut on a cherry invites bacterial canker. |
| HornbeamCarpinus betulus · Charme | hedge | 2,00 m | 0,33 m | 6 € | Holds its brown leaf through winter and is the cheapest good hedge on clay. |
| SilverberryElaeagnus × ebbingei · Chalef | hedge | 2,50 m | 0,60 m | 15 € | Evergreen, salt- and wind-proof: the hedge for an exposed or coastal boundary. |
| Cotton lavenderSantolina chamaecyparissus · Santoline | shrub | 0,50 m | 0,50 m | 8 € | Silver mounds that hold their shape all winter and ask for nothing. |
| LaurustinusViburnum tinus · Laurier-tin | shrub | 2,50 m | 1,20 m | 16 € | Evergreen screen that flowers in January, which is when you need it. |
| LavenderLavandula × intermedia 'Grosso' · Lavandin | shrub | 0,80 m | 0,60 m | 9 € | Dies of wet feet, not of cold. On clay it goes on a 20 cm gravel ridge. |
| Rock roseCistus × purpureus · Ciste | shrub | 1,20 m | 1,00 m | 12 € | Flowers for six weeks on poor ground and resents being fed. |
| RosemarySalvia rosmarinus · Romarin | shrub | 1,20 m | 0,80 m | 11 € | Evergreen structure and a kitchen crop from the same plant. |
| Autumn moor grassSesleria autumnalis · Seslérie d'automne | grass | 0,50 m | 0,40 m | 7 € | Plant in blocks as a low matrix: it closes the ground and stops weeding. |
| Golden oatsStipa gigantea · Avoine géante | grass | 1,80 m | 1,00 m | 13 € | Holds its structure through winter and catches low western light. |
| Hardy geraniumGeranium × oxonianum 'Claridge Druce' · Géranium vivace | perennial | 0,50 m | 0,50 m | 6 € | Covers ground under shrubs on heavy soil and asks for one cut a year. |
| Lenten roseHelleborus × hybridus · Hellébore | perennial | 0,50 m | 0,50 m | 14 € | Flowers in February under the canopy, when nothing else does. |
| Mediterranean spurgeEuphorbia characias subsp. wulfenii · Euphorbe des garrigues | perennial | 1,10 m | 0,80 m | 10 € | Architectural all winter. Wear gloves: the sap burns skin in sunlight. |
| ThymeThymus vulgaris · Thym | perennial | 0,30 m | 0,30 m | 5 € | Plant it where you walk past it, at the terrace edge and along the path. |
| Wood sageSalvia nemorosa 'Caradonna' · Sauge des bois | perennial | 0,60 m | 0,40 m | 7 € | Flowers twice if you cut it back hard after the first flush. |
| YarrowAchillea 'Terracotta' · Achillée | perennial | 0,70 m | 0,50 m | 7 € | Flat heads that read well against grasses, and it does not need staking on poor soil. |
What we would not plant here
Each of these is a good plant on the ground it was bred for, and a mistake on yours. This is the list our own palette leaves out for a site on chalky soil.
- 01Snowy mespilus (Amelanchier lamarckii) — wants loam, sand or clay: above pH 7.5 it cannot take up iron: yellow leaves with green veins, then a slow decline no feed corrects.
- 02Panicled hydrangea (Hydrangea paniculata 'Limelight') — wants clay or loam: above pH 7.5 it cannot take up iron: yellow leaves with green veins, then a slow decline no feed corrects.
- 03Japanese holly (Ilex crenata 'Dark Green') — wants loam, clay or sand: above pH 7.5 it cannot take up iron: yellow leaves with green veins, then a slow decline no feed corrects.
- 04Purple moor grass (Molinia caerulea 'Transparent') — wants clay or loam: above pH 7.5 it cannot take up iron: yellow leaves with green veins, then a slow decline no feed corrects.
- 05Japanese forest grass (Hakonechloa macra) — wants loam or clay: above pH 7.5 it cannot take up iron: yellow leaves with green veins, then a slow decline no feed corrects.
- 06Soft shield fern (Polystichum setiferum) — wants clay or loam: above pH 7.5 it cannot take up iron: yellow leaves with green veins, then a slow decline no feed corrects.
- 07Blackcurrant (Ribes nigrum 'Andega') — wants clay or loam: above pH 7.5 it cannot take up iron: yellow leaves with green veins, then a slow decline no feed corrects.
- 08Autumn raspberry (Rubus idaeus 'Zeva') — wants loam, sand or clay: above pH 7.5 it cannot take up iron: yellow leaves with green veins, then a slow decline no feed corrects.
- 09Strawberry (Fragaria × ananassa 'Mara des Bois') — wants loam or sand: above pH 7.5 it cannot take up iron: yellow leaves with green veins, then a slow decline no feed corrects.
- 10Garden mint (Mentha spicata) — wants clay or loam: above pH 7.5 it cannot take up iron: yellow leaves with green veins, then a slow decline no feed corrects.
Soil is one of three filters. Hardiness decides whether a plant survives your winter, exposure decides whether it flowers, and only then does soil matter. A plant list that ignores any of the three is decoration.