Getting started
Sowing and space
Plant healthy traceable slips only after the root zone is warm and allow room for vines and storage roots.
Allow about 40 cm of usable depth and roughly 35 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.
A warm sheltered bed or large container offers the best chance of root development.
Drier eastern lowland
Plan for water conservation and cold-air pockets; a dry spring can delay germination even when daytime temperatures look suitable.
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.
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.
The normal outdoor season may be too cool or short.
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.
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.
Reliable storage-root production outdoors is unlikely without local evidence.
Practical care
- Use loose deep soil or compost.
- Lift before damaging cold reaches the crop.
Points to check
- Do not use ornamental plants of unknown treatment history.
- Cold wet soil can rot slips.
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.
Bringing plants and wood into Great Britain
UK Government and Animal and Plant Health Agency
Supports checking current rules before bringing or ordering plants and seeds. Great Britain and Northern Ireland can have different requirements.
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.