Getting started
Sowing and space
Direct-sow the seed clusters thinly and thin seedlings before roots become crowded.
Allow about 25 cm of usable depth and roughly 12 cm between plants.
Watering reference: moderate and regular. Adjust to rain, heat, wind, growth stage and container volume.
Planting windows by broad profile
These original editorial windows compare thermal groups, not live weather. Check current frost, heat, rainfall and packet directions.
Mild south-west and coast
Check the actual last frost, soil drainage, salt exposure and wind shelter; a protected coastal plot can differ sharply from a nearby inland hollow.
Southern lowland
Do not treat a regional average as a frost date. Check the current forecast, water restrictions and the temperature of the actual soil or container.
Drier eastern lowland
Plan for water conservation and cold-air pockets; a dry spring can delay germination even when daytime temperatures look suitable.
Keep the seed row evenly moist during dry spring weather.
Wet western maritime
Prioritise drainage, shelter and safe support. A broad wet profile is not a reason to skip checking the root zone before watering.
Avoid a compacted or saturated root zone.
Cool northern lowland
Use local frost observations and an early cultivar as separate pieces of evidence; neither guarantees that a tender crop will finish outdoors.
Upland, short season
Confirm soil warmth, exposure and the remaining frost-free period at the plot. Covers must be secure, ventilated and removed when unsafe.
Wait for workable soil and use a short main-season sowing band.
Northern island and coast
Choose shelter without blocking access or drainage, and compare the plot with current local forecasts rather than a mainland monthly average.
Practical care
- Thin early and use the packet spacing for the chosen cultivar.
- Water the root zone rather than wetting only the surface.
Points to check
- Stony or compacted soil can distort roots.
- Long irregular dry periods can reduce quality.
Provenance and confidence
This rule is an original editorial synthesis and no independent local agronomic review is claimed.
United Kingdom home food garden editorial synthesis — version 1
Global Garden Planner
Original seven-profile model, planting bands and en-GB corpus. It remains an editorial draft until an independent UK agronomic review is recorded.
UK regional climates
Met Office
Supports broad east–west, north–south, maritime and topographic context. The project profiles and month bands are original and are not a transformation of Met Office regions or data.
Positioning vegetables
Royal Horticultural Society
Supports observing sun, shade, shelter and competition at the final growing position.
Planning a vegetable garden
Royal Horticultural Society
Supports considering soil, cultivar and available space. It is not used to create the package calendar bands.
Use it in context
A month alone cannot resolve cultivar, soil, microclimate or a current extreme.
Use reputable planting material. Use clearly labelled seed or healthy young plants from a traceable supplier and check current plant-health rules, including the distinct arrangements for Great Britain and Northern Ireland, before ordering or moving material.
If a plant protection product is considered at all, check the current GB or Northern Ireland authorisation for the crop and use, then follow the complete label; the project does not prescribe a treatment.