Sources and how they are used
28 organisations are registered and 24 are currently cited. Each entry records what it is authoritative for and what GrowingHQ is permitted to do with it.
GrowingHQ cites. It does not copy.
Every source here is marked “cite only” or is GrowingHQ’s own editorial position. Nothing is fetched by a collector, nothing is parsed, and no prose is transcribed. A human editor reads the guidance, establishes the horticultural facts, and writes them into GrowingHQ’s own structured fields with the source named. Citations record where to look, not what somebody else wrote.
Cited in the catalogue
| Source | What it is authoritative for | Weight | How we use it |
|---|---|---|---|
| SoilscapesCranfield University, National Soil Resources Institutewww.landis.org.uk/soilscapes | Simplified national soil classification: texture, drainage class, natural fertility and depth for the soil associations of England and Wales. GrowingHQ's authority for what a named garden soil actually IS, as distinct from what a plant would like. | Primary | Cite only — no transcriptionConsulted by a human editor for soil classification. Nothing is transcribed; the named soil records here are GrowingHQ's own descriptions of soil classes, not reproductions of any dataset. |
| James Hutton InstituteThe James Hutton Institutewww.hutton.ac.uk | Soil science, soil structure and the physical behaviour of soils under cultivation. Cited for compaction, structural damage and organic-matter effects — the mechanisms behind soil improvement rather than the recommendations. | Primary | Cite only — no transcriptionResearch publications read and cited by a human editor. Nothing is transcribed. |
| Royal Horticultural SocietyRoyal Horticultural Societywww.rhs.org.uk | UK growing practice, sowing and harvesting seasons, hardiness ratings, plant selection and pest and disease guidance. The primary authority for anything time-of-year in a British garden. | Primary | Cite only — no transcriptionAll rights reserved. GrowingHQ cites RHS guidance and never transcribes it; horticultural facts are re-expressed in GrowingHQ's own structured fields. |
| Plants of the World OnlineRoyal Botanic Gardens, Kewpowo.science.kew.org | Accepted botanical names, synonymy, family placement and native distribution. Authoritative for what a plant is called; says nothing about how to grow it. | Primary | Cite only — no transcriptionConsulted by a human editor for nomenclature. Names themselves are facts, not expression; nothing is transcribed. |
| GRIN TaxonomyUnited States Department of Agriculture, Agricultural Research Servicenpgsweb.ars-grin.gov | Crop plant nomenclature, cultivar groups and economic-plant classification. Particularly useful where a vegetable is a cultivar group rather than a species — brassicas above all. | Primary | Cite only — no transcriptionUS federal work and largely free of copyright, but GrowingHQ still cites rather than copies, so the handling rule does not depend on a licence judgement. |
| Plant FinderMissouri Botanical Gardenwww.missouribotanicalgarden.org | Cultivation requirements, mature dimensions, light and soil preferences for a very wide range of garden plants. Written for a continental North American climate. | Secondary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| University of Minnesota ExtensionUniversity of Minnesotaextension.umn.edu | Vegetable growing, soil management, plant disease and pest diagnosis. Cold-climate context: its frost dates and season lengths are not British ones. | Primary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| Home and Garden Information CenterClemson Cooperative Extensionhgic.clemson.edu | Vegetable and herb culture, plant problems and soil. Warm-temperate context, which makes it useful on heat tolerance and bolting and unreliable on British sowing dates. | Primary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| OSU Extension ServiceOregon State Universityextension.oregonstate.edu | Vegetable production, soil temperature and germination data, and maritime-climate growing — the closest widely published analogue to British conditions. | Primary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| USU ExtensionUtah State Universityextension.usu.edu | Vegetable culture, irrigation and season extension in a dry continental climate. | Secondary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| Penn State ExtensionPennsylvania State Universityextension.psu.edu | Vegetable crops, plant disease diagnosis and integrated pest management. | Primary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| University of Maryland ExtensionUniversity of Marylandextension.umd.edu | Home food gardening, container growing and vegetable problem diagnosis. | Secondary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| UC Statewide Integrated Pest Management ProgramUniversity of California Agriculture and Natural Resourcesipm.ucanr.edu | Pest and disease biology, life cycles and non-chemical management. Cited for how an organism behaves, never for what to spray: approvals are jurisdictional and Californian ones do not apply in the UK. | Primary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| MSU ExtensionMichigan State Universitywww.canr.msu.edu/extension | Vegetable production, soil fertility and plant nutrition. | Secondary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| GOV.UK guidanceUK Governmentwww.gov.uk | Statutory guidance on plant health, invasive species, waste and land management. Authoritative on what is legally required in the UK, and on nothing horticultural beyond that. | Primary | Cite only — no transcriptionOpen Government Licence permits reuse with attribution. GrowingHQ still restates rather than reproduces, so a licence change cannot invalidate published pages. |
| Agriculture and Horticulture Development BoardAHDBahdb.org.uk | UK commercial horticulture agronomy, crop physiology and disease management. Commercial-scale context that often does not transfer directly to a garden. | Secondary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| Garden OrganicGarden Organic (Henry Doubleday Research Association)www.gardenorganic.org.uk | Organic growing practice in the UK: rotation, green manures, composting and non-chemical pest management. | Secondary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| NIABNational Institute of Agricultural Botanywww.niab.com | UK top-fruit and soft-fruit research: rootstock development and evaluation, cultivar assessment and orchard agronomy. The institute behind much of the British rootstock series in use today, which makes it the right authority for vigour classes rather than a nursery catalogue. | Primary | Cite only — no transcriptionAll rights reserved. Cited for rootstock and cultivar characteristics; nothing transcribed. |
| Cornell Fruit ResourcesCornell University, College of Agriculture and Life Sciencescals.cornell.edu | Tree fruit, berry and grape production: pollination biology, rootstock performance, training systems and disease cycles. Cool-temperate context, which transfers to Britain better than most US material. | Primary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| WSU ExtensionWashington State Universityextension.wsu.edu | Tree fruit horticulture — pome and stone fruit pollination, chill requirement, rootstock and orchard systems — from one of the largest temperate tree-fruit growing regions in the world. | Primary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| Purdue ExtensionPurdue Universityextension.purdue.edu | Controlled-environment and soilless production: hydroponic technique selection, solution management principles and crop suitability. Cited for how a technique behaves, never for a nutrient formulation. | Secondary | Cite only — no transcriptionAll rights reserved. Cited, never transcribed. |
| ASPCA Animal Poison Control Center — toxic and non-toxic plant listAmerican Society for the Prevention of Cruelty to Animalswww.aspca.org/pet-care/animal-poison-control | Plant toxicity to cats, dogs and horses, maintained by a veterinary poison-control centre and organised as two explicit lists — toxic and non-toxic. GrowingHQ's authority for the positive finding that a taxon has been assessed and is not toxic, which no horticultural source makes. Not an authority on how to grow anything. | Primary | Cite only — no transcriptionConsulted by a human editor per taxon. Nothing is transcribed: the verdict recorded here is a three-state field in GrowingHQ's own vocabulary, and the mechanism and symptom wording is written by GrowingHQ from the established toxicology rather than reproduced. |
| Veterinary Poisons Information ServiceVPIS, Londonwww.vpisglobal.com | Veterinary toxicology enquiry service for UK practices, and the closest UK equivalent to a poison-control plant list. Cited for the severity and clinical course of a poisoning rather than for list membership, because the service publishes case-derived guidance rather than an enumerated non-toxic list. | Primary | Cite only — no transcriptionPublished guidance read by a human editor. Nothing is transcribed and no case data is reproduced. |
| GrowingHQ editorial synthesisGrowingHQ | GrowingHQ's own positions, taken where practical guidance converges across the horticultural literature without any single document establishing it, or where a judgement has to be made and labelled as one. | GrowingHQ editorial | GrowingHQ's own positionGrowingHQ's own work. Exists as a named source so that an editorial position can never be presented as though it came from somewhere else. |
Registered but not yet cited
Sources cleared for use whose material has not been drawn on yet. Listed separately so the register cannot be read as a claim about how widely GrowingHQ has researched.
- HSE pesticides guidance
- UK Plant Health Information Portal
- EPPO Global Database
- Pet Poison Helpline
When there is no source to cite
Much practical growing guidance is not a citable measurement in any single document. “Basil sulks below about 10 °C” is a convergence across decades of practice, not a figure from a paper. Pretending such a number came from a specific study would be fabricating a citation; presenting it as an unsourced fact would be worse.
So it gets its own source type — GrowingHQ editorial synthesis — its own evidence type, and a visible label on the page saying it is our position rather than somebody else’s finding. An audit forbids it from ever being dressed up as anything else. How the evidence model works.