The invention relates to lighting method and devices that can be used to treata seedling in agrowth chamber or greenhouse prior to the introduction of the seedling tooutdoors. One aspectof the invention is a light by which the plants can be prepared for theoutdoors, by giving themcertain wavelengths of light they do not currently receive from the light inthe greenhouse orgrowth chambers. The light of the invention can be applied in smaller dosesduring the majorpart of nursing of the seedlings or as a sun-shock period in the end of theindoors nursing period.By giving the seedlings light from the invention, they are prepared to Sunlight and do not needto spend a few weeks under the sunshade curtains. The invention thus shortensthe growth cycleof tree seedlings, enhances the proportion of viable seedlings and eliminatesone work phase inthe growth process, thus improving the economics of seedling cultivation.
