Growing Conditions · Wales
Carmarthenshire Growing Conditions
Soil, hardiness and a planting calendar for Carmarthenshire — across 17 postcode districts.
Soil
The soil most gardeners wish for: a free-draining, slightly acid loam that warms early in spring and rarely waterlogs. It suits the widest range of planting — vegetables, perennials, shrubs and trees — and asks little beyond an annual mulch to keep its structure. Because it drains freely it can dry in a hot summer, so new plants, pots and lawns benefit from steady watering through July and August. For patios, paths and walls its stability makes for straightforward foundations.
Winter hardiness
Rated RHS H4 — the UK mainstream, with winter lows near -7°C. The vast majority of garden plants, perennials, shrubs and trees come through a normal winter unprotected; only genuinely tender exotics need a warm corner or cover.
Rain & growing season
A very wet climate (1387mm a year) — drainage is the priority, moisture-loving planting thrives, and paving and lawns must be laid to drain. A long growing season (~346 frost-free days) — you can sow earlier and harvest later than most of the country, and squeeze in a second late sowing.
Planting Calendar for Carmarthenshire
The long season allows a second sowing of quick crops in July.
Timings are guided by this area's ~346 frost-free days and RHS H4 hardiness; adjust for a cold or sheltered garden.
Conditions by Postcode
| Postcode | Soil | Hardiness | Rainfall |
|---|---|---|---|
| SA14 | free-draining acid loam — the classic 'good garden soil' | RHS H4 | 1345mm |
| SA15 | free-draining acid loam — the classic 'good garden soil' | RHS H4 | 1410mm |
| SA17 | free-draining acid loam — the classic 'good garden soil' | RHS H4 | 1410mm |
| SA18 | acid clay loam, seasonally wet | RHS H4 | 1345mm |
| SA19 | acid clay loam, seasonally wet | RHS H4 | 1345mm |
| SA31 | shallow, free-draining acid loam over rock | RHS H4 | 1410mm |
| SA32 | free-draining acid loam — the classic 'good garden soil' | RHS H4 | 1410mm |
| SA33 | free-draining acid loam — the classic 'good garden soil' | RHS H4 | 1410mm |
| SA34 | shallow, free-draining acid loam over rock | RHS H4 | 1410mm |
| SA38 | free-draining floodplain loam | RHS H4 | 1410mm |
| SA39 | free-draining acid loam — the classic 'good garden soil' | RHS H4 | 1410mm |
| SA4 | free-draining acid loam — the classic 'good garden soil' | RHS H4 | 1345mm |
| SA40 | acid clay loam, seasonally wet | RHS H4 | 1410mm |
| SA48 | acid clay loam, seasonally wet | RHS H4 | 1341mm |
| SA66 | fertile floodplain soil with a high water table | RHS H3 | 1415mm |
| SA67 | free-draining acid loam — the classic 'good garden soil' | RHS H3 | 1415mm |
| SA9 | restored quarry/opencast ground — variable | RHS H4 | 1345mm |
Planning work in Carmarthenshire?
Browse Companies House-registered landscaping businesses in the area.
