Seeding of cucumbers mostly take place directly into the rockwool blocks.
Use the special fertilizer recipe for seeding named; ‘wetting blocks seeding cucumbers’.
Flush extra feed solution trough the blocks to get nice uniform water content, EC and pH. The measured values of EC and pH must be similar to the dosed fertilizer solution. Best should be an automatic watering system that all blocks get sure the same amount of wetting solution. Water supply with hand hose needs very good attention to be sure that blocks are full wetted (saturated) and flushed in the right amount. This amount must be according to the recommended volume (1500 ml per block).
After good wetting and flushing the blocks contain the good feed solution for seeding.
Use heated water for wetting the seeding blocks or make a possibility to bring the block temperature at the optimal level (cucumber 26-27 oC). Check before and during the germination the temperature by the seed.
Put the seed in the block, cover it with Vermiculite nr.3 and don’t sprinkle water for better aeration of the seed in the first day(s). Cover the blocks with 2 cm thick polystyrene plates to keep the right germination temperature.
Check germination temperature very frequently (day and night!) especially by floor heating to avoid overheating. Absolute maximum temperature is 28C!
Transplanting seedlings in rockwool blocks
Use the ‘start propagation fertilizer solution’ for your specific crop.
Transplant seedling in rockwool plugs not upside down into the rockwool blocks, because that can harm the hypocotyls and roots, delay growing with 2 or 3 days and make plants more generative. So, preferable is to transplant seedlings street up to safe roots, getting quicker rooting into the blocks and better stem base.
After transplanting regularly the wetness of the blocks must be checked with scale. Start water supply before the block weight goes below about 2/3 of the full saturation weight. By sunny weather and/or big plants the water supply must start earlier.
Check the EC and pH value of the blocks and also the drain-water runoff frequently!
Use small size of irrigation spray head under the leafs by water supply to the blocks. Don’t make leafs wet with fertilized solution!
By propagating big plants a bamboo support could be needed to avoid collapsing plants.
Preparation of the greenhouse before planting
Make the ‘drain gutters’ (10 cm wide x 5 cm deep).
Make a slope in the ‘soil gutter’ of about 0, 15% for drain collecting at the end of the bay.
Clean and disinfect the greenhouse before soil will be covered.
Place strong foil into the ‘soil drain gutter’.
Cover total soil surface including drain gutter with strong white PE foil (Rotaflex).
Place the slabs on the soil covering foil just beside the underneath drain gutter.
If the soil surface is not completely flat, place a ‘polystyrene’ plate under the slab with 5 mm slope in the direction of the drain gutter.
Prepare the planting holes in the rockwool slabs in same size as the block size. Make the ‘door system’ with three knife cuts per hole or use electric hole cutter.