Gardening at the Arctic - ways of raising soil temperature (and extending growing season)

RAISING TEMPERATURE

• Windbreaks (by using transparent thick plastic, the plants are protected by the winds, wildlife finds a sheltered spot, and the sun heats through the plastic increasing the air temperature around the plants (up to 2ºC)
• Use raised beds and slope beds (facing the sun) to increase the soil temperate- raised soil warms much faster than surrounding soil. Use black sandy soil, near the surface.
• Avove or within the soil, place a mulch of decomposing grass (when it decomposes it releases heat.
• Use clear plastic mulch, above the soil and grass mulch (this increases much more the soil temperature)
• Use microclimate; place certain plants in a protected spot amongst other taller and bushier plant. Also planting against a south oriented wall, has a higher temperature than other spots (around 2ºC).

FROST PROTECTION

• Any sheltered spot, near a wall, has also higher temperature (usually up to 2ºC), and much less frost.
• Sandy soil freezes less, and warms faster. Count up to 2ºC more, when sun shines.
• Use peatmoss as a protection against hard freezes. Cover plants also with a plastic for extra protection. Both can raise the soil temperature up to 2ºC. Bare soil is the worst, it will freeze hard, without any protection. 
• Use fleece as an easy way to protect all plants from frosts. A fleece prevents frost formation down to -3ºC, but usually only raises about 1ºC of the night temperature.
• Use a cold frame to protect young seedlings. Cold frame can increase night temperature up to 2ºC and significantly more during sunshine. If you use all methods above, you can prevent the soil from freezing even when it gets to -10ºC.