Glossary J

John Innes

John Innes composts were developed as a standardised range of loam based composts, created to reduce the confusion which existed in the market place at the time. The John Innes Horticultural Institute was founded in 1904, ‘for the improvement of horticulture by experiment and research’. The range includes…

• John Innes seed compost, for seed sowing or rooting cuttings.
• John Innes potting compost No.1 for initial potting.
• John Innes potting compost No.2 for potting on.
• John Innes compost No.3 for final potting of stock plants.

Composts like this, which are soil based, should be stored in dry conditions and used within a month of purchase.

Juvenile

Some plants will have a stage between seedling and mature plant, where they demonstrate different characteristics. Generally, a juvenile will be smaller and lack reproductive capability. In Beech hedges, juvenile growth will hold onto its leaves through the winter until bud burst. This is sustained by regular trimming every year, or the hedge would begin producing mature growth, which would not retain the leaves through the winter.