On artificial grounds, especially on the roofs of tall buildings, the plants are in different microclimatic conditions than on earth – in their familiar surroundings. Microclimate at high elevations close to the mountain: high solar radiation, wind, solid base of a small forced to soil, more dramatic, as in the mountains, fluctuations in temperature. Plants suffering from summer heat, dry air and lack of moisture in the winter – from soil freezing. Serious danger for them is the wind speed which increases with altitude: at the level of the ninth floor of her 1,5-2 times higher than at ground level and a roof 16-20-storey buildings have wind Load up to 5 times greater than the surface. Wind not only causes mechanical damage to plants and the soil dries much faster than on land, it increases evaporation from the leaf surface and lowers the temperature of the plants. Normal plant development as it is impossible without a corresponding amount of heat and a certain temperature, they are able to move without damage, especially in winter.

Frost resistance is the root systems are usually much smaller than that of shoots. For example, the roots of acacia damaged already at a temperature of – 6-7 C, large-lime – at – 14 C. More frost-Siberian plants, such as apple Siberian withstands temperatures down to 25 C, and spruce – up to 33 C. Unfavorable for plant and temperature fluctuations during the winter, as well as possible heating the roof from below, from the building itself.