HORTICULTURE & AGRICULTURE > SUGGESTED MIX

Seed germination
Vermiculite is ideal for the germination of seeds because the aeration properties combined with its water holding capacity makes it a superb medium for direct contact with the seeds. Excellent for laboratory seed germination tests and pre-chitting seeds for commercial growers.
Large and small seeds can be raised in pure vermiculite. Slower germination seeds may be raised with a 50/50 mix of vermiculite and peat or perlite.
Vermiculite can be used as a soil improver. When applied to an outdoor seed bed it will give improved emergence and less risk of capping.

Sowing Composts
Vermiculite in sowing composts encourages quicker germination, improved seed growth, and less check when pricking-out or potting on. Sow on a well-watered and drained mixture of equal parts of vermiculite and peat or perlite. Alternately, add one part vermiculite to two parts of ready mixed seed compost, posting or all-purpose compost. The proportion of vermiculite may be increased to 75% for large slower-germinating seeds.
Sow thinly, evenly and not too deep. Cover lightly with free flowing moist vermiculite. Avoid over firming. Put the container in a warm place until the seeds germinate, then move to a light position. Keep moist with a fine drenching mist as necessary.
Seedlings are easily removed from vermiculite compost without damage to the fine roots and they transplant with a minimum of disturbance.

Seedling Wedge Mix
Vermiculite mixed with up to 20% of fine peat or blocking compost is recommended for most of the wedge shaped plug module systems of vegetable and bedding plant propagation and transplanting.
The 'Speeding' system of large scale peat module production, developed in the U.S. uses vermiculite in the mix to safeguard against water logging in the peat wedges, facilitate re-wetting and to ensure the optimum air/water relationship for rapid seed germination and sturdy growth.
Mixes of vermiculite or perlite will require the addition of lime and nutrients in accordance with specific crop requirements.
Vermiculite is also applied as reflective surface and protective covering after seedling module trays for raising varieties of bedding, and plants and vegetable transplants.

Root cuttings
Water the vermiculite and perlite/peat mix before inserting cuttings and do not compress around the base of the cutting.
A 50/50 mix (with either peat of perlite) is generally suitable for soft cuttings on the open bench or under plastic covers (do not use vermiculite under mist).
Thoroughly water the vermiculite before inserting cuttings and do not compress around the base of the cutting.

Blocking
Vermiculite can be used where the seed has been placed into growing blocks.
Vermiculite encourages better aeration, drainage and insulation without prejudicing the stability of the block.
Germination can be further improved by covering the seeded blocks with a layer of vermiculite. This will also facilitate re-wetting of the block and insulate the seed from excessive temperature fluctuations.

Micro propagation
Vermiculite has special properties which favour the weaning of tissue cultured plants from the test tube stage to the commercial glasshouse. Such plants may be entirely without root hairs, and they will suffer readily from water-stress.
Vermiculite/peat mixes have been found to provide a most suitable medium for plants at this stage of development. A 50/50 mix is recommended as a starting