Eight plant species were grown as pot plants on different substrates. Rockwool slabs remained after 2-year carnations culture were shredded, steamed and used alone or in the mixtures with another components. For comparison purpose the standard medium (peat plus perlite) and the mixtures similar to investigated were prepared with the use of new, glanulated rockwool instead of utilized rockwool. Results indicate, that the plant growth on substrates based on utilized rockwool was as good or better than on the comparative or standard substrates. The best substrate was the rockwool plus peat (1:1).
The experiments were caried out in 1997 in unheated greenhouse in random block system at 4 repetitions. The aim was to evaluate the usefulness of four greenhouse cucumber varieties for growing on two reused rockwool substrates. The study indicated that Promyk F₁, Dukat F₁, Orion F₁ i Kosmos F₁ varieties are healthy, high yielding of good quality fruits. Mean 1-st class yield of these varieties was 27.41, 26.88, 27.48 and 26,53 kg/ m² respectively, what was 86-91% commercial yield. Reused Flormin and Grodan rockwools were valuable substrates for growing cucumber in greenhouse.