In some countries, which have the field of seedling production, it is very important to produce at an advanced level in vegetable cultivation. In Turkey, already traditional methods of seedling production are widely available. However, in recent times the use of soil conditioners has attracted considerable attention in organic and conventional breeding. Soil conditioners are divided into organic (such as straw-straw, compost, vegetable wastes, worm or poultry stew, plant extracts) or inorganic (such as perlite, sand, clay, vermiculite). In this context, studies on suitable environments and methods for growing seedlings are ongoing. In our study, lettuce, rocket, tomato and cabbage leaf extracts were applied in different combinations like liquid fertilizer. Number of leaves and shoots, leaf width, crown thickness, seedling height, chlorophyll measurement and presence of anthocyanins were determined from cauliflower, broccoli, parsley, cabbage and lettuce. The effects of these applications varied according to the species, and almost all applications were found to increase the measured parameters.