Studies have been conducted on the influence of a variable magnetic field, magnetically treated water and a combination of both of these factors on the final mass of seedlings, height of sunflower plants, contents of potassium and calcium as well as other nutrients in the initial phase of growth. Magnetic stimulation of seeds took place at a research magnetic field system, at induction of 30 mT, frequency of 50 Hz and durations of 15 s and 30 s. Water flowed 3 times through a teflon tube placed between direct current electromagnet pole pieces at induction of 150 mT at the measurement post. Investigations were carried out in pots filled with humus soil, in an air–conditioned greenhouse hall with no access to daylight, using fluorescent light as illumination. The samples of seedlings were taken every 5 days. A positive impact was achieved on the final mass of sunflower plants for the sample in the 5-day initial phase of plant growth. No impact of the stimulation factors on the contents of potassium and calcium and other nutrients in seedlings were observed.