The show has 5 classes for roses The RHS advice on judging is comprehensive, this is just a summary to get you started
Stem: An original new growth with no lateral stems Double bloom: Has more than 20 petals Semi Double: Between 8 & 20 petals Single Bloom: has less than 8 petals Miniature Rose: Tiny in every respect from flowers to leaves Cluster flowered - Two or more blooms, gracefully arranged & spaced Side buds allowed except in classes for specimen blooms or 3 stage roses Additional Foliage: Not allowed Wiring: A single wire may be used to hold a large flowered rose head erect
Defects: Irregular outline, fewer than average number of petals, petals, split, stained or damaged immature or over developed blooms. Stems weak and twisted, poor thin foliage, untidy presentation Flowers either crushed together or too widely spaced.
Marking Advice Form & Size of individual blooms, form of cluster, stage of development 5 points Freshness, brilliance & purity of colour 5 points Stems & Foliage 3 points Presentation 7 points TOTAL 20 points