Hyssop (Hyssopus officinalis L.) obtained from various commercial sour
ces was grown for three years (1990-1992) in Finland. Yield characteri
stics, flower colour, volatile oil content/composition and its antimic
robial quality were studied. For comparison, Scottish-grown hyssop was
included in oil and quality determinations. The description of the fl
ower colour given by the seed firms was not a reliable indicator of th
e true colour in many cases. Oil yield was satisfactory and oil compos
ition was rather uniform. Only one different chemotype was identified,
this was derived from a Romanian seed source. There was considerable
variation in herb yield between plants from different sources. The tot
al fresh herb yield was 0.5-3.2 kg/m2, the dry leaf yield was 67-326 g
/m2. Seed germination was satisfactory (76-99%), offering opportunitie
s for seed production of varieties with different characteristics.