Describe a range of compost types.

To include: peat based, peat free (coir, composted green waste, composted bark), ericaceous, loam based, seed compost, potting compost, multi-purpose compost.

PEAT BASED COMPOST

Peat Based: (Either peat on its own or a peat/grit/sand mixture). Widely use to replace loam based compost; Light weight, needs feeding, holds water well, produces plants fairly easily, (bedding plants, pot plants, young vegetables for planting out and specialist plants like exhibition Begonias).

JOHN INNES

JOHN INNES COMPOST The range of strengths gave composts for differing uses:

Seed: For seed sowing of fine seed. Low nutrient value avoids ‘burning’ of seedlings. Assume to be pricked out <6 weeks after germination. Number 1: pricking out/potting rooted cuttings/plants that like a low nutritional content (Calceolaria);

Number 2: general potting compost; Potting on geraniums or hardy stock.

Number 3: final potting compost for crops like Chrysanthemum/Tomatoes. Or for long term specimen plants, Azaleas, Palms, Trees, & shrubs. Bl The John Innes range of composts introduced in the 1940s were the first scientifically developed standard composts. Based on partially sterilised loam (Lawrence and Newell). The compost is heavy with a good natural food content (N.P.K. and trace elements), is enriched with fertilisers, the pH is about 6.5, has a natural root zone giving good root stability and clay content which holds on to added fertilisers.

JOHN INNES 1 John Innes Formula for potting compost Number 1: 7 parts loam; 3 parts peat; 2 parts grit. Parts by bulk: Plus 4oz J.I. base fertiliser per bushel (a box 10” x 10” x 22”); And ¾oz chalk.

JOHN INNES 2 (Number 2: 2 x base fertiliser and chalk, Number 3: 3 x base fertiliser and chalk).

JOHN INNES 3 (Number 2: 2 x base fertiliser and chalk, Number 3: 3 x base fertiliser and chalk).

PEAT FREE COMPOST

Peat Free: (Many mixtures have and are still being tried as a replacement for peat). Coir coconut fibre (oil miles)?? – wet in the bottom of the pot/dry on the top, if used on its own (good in a mixture); Not very available currently? Composted green waste, widely used but may Variable in pH and texture ( depending on process and original material, may harbour pathogens though becoming less of a problem as processing becomes more standard.– Composted bark – consistent – you need to learn how to use it. Use as for peat although proves difficult to manage and produce good plants easily; Recommended by RHS. Sylva fibre Ericaceous – a loam/peat or peat free compost with a LOW acid pH making it suitable for growing acid loving plants in containers. Needs to be kept acid by use of acid water/liquid feeds (Miracid) or a top dressing with ericaceous compost.

COIR Coir coconut fibre (oil miles)?? – wet in the bottom of the pot/dry on the top, if used on its own (good in a mixture); Not very available currently?

COMPOSTED GREEN WASTE (commercially produced garden compost): Should be the same as garden compost; Good recycling; Look to its quality – may contain pathogens or plant disease- Temperature

SYLVA FIBRE

A fine composted British wood-fibre designed as a major growing medium ingredient, ideal for peat-free or peat-reduced plant production.

Key Benefits:

Provides excellent air-water balance enabling the production of high quality plants Ideal for peat-free or peat-reduced plant production Equally suitable for ericaceous and non-ericaceous subjects Low nutrient level allows complete control over fertilizer additions Competitively priced compared to peat Structural durability makes Sylvafibre® ideal for long term crops Suitable on all types of bed, including sand, gravel and capillary matting Can also be used as a propagating medium Can also be used as a pot mulch Tried and tested over many years

COMPOSTED BARK eg sylva fibre

JOHN INNES SEED COMPOST

Seed: 2 parts loam; 2 parts peat; 1 parts grit; Plus 1½oz superphosphate; And ¾oz chalk per bushel.

POTTING COMPOST Can be loam/peat or peat free; Full range of food content; For seed potting up plants.

MULTI -PURPOSE COMPOST Usually peat or peat free based and suited to seed sowing or potting.

Describe ONE NAMED situation to illustrate the use of each compost type.

Identify the environmental implications of peat in growing media.

PEAT SUSTAINABILITY

Identify the environmental implication of peat in growing media. In the 1990s the issue was first brought up by the R.S.P.B. as a concern over the loss of wet land habitat for birds. They were joined by the National Trust and lobbied the government. It was said that stopping the use of peat in horticulture would be a way to mark the millennium. Research work started to find suitable alternative materials for making composts. The National Trust made 3 attempts to develop their own brand of compost (failed) – and the millennium came and went.

The coalition government has brought back the issue as a way of Britain cutting its carbon footprint and the same environmental issues. They are requesting that local authorities stop the use of peat by 2015, the public stop the use of peat by 2020 and commercial users by 2030. It is still difficult to find a stable and uniform compost that grows plants easily.