De-icing salts represent a serious problem in all cold countries, since they damage the plants along the streets in ‘guardrail’ flower-beds, inducing the presence of dry leaves, necroses, malformations and anomalies, so as to be diagnosed as an attack of pathogens. In most cases the first visible effect of a high salt content in the ground are necrotic areas on the leaves. In these areas there is the accumulation of salts which undoubtedly causes partial or total destruction of chlorophyll and therefore the death of these parts. The speed and intensity of the necrosis depends above all on the biological properties of the salt and on the kind of salt in the soil. To evaluate the damage on the widely used shrub Cotoneaster salicifolius, plants were treated using three kinds of salts (sodium chloride [NaCl2], calcium chloride [CaCl2] and sodium sulphate [Na2SO2]) at two different concentrations (0.25 N; 0.125 N). The most important damage was caused by root absorption of solutions salts containing chloride ions. The typical symptoms were necrotic areas on the leaves. To evaluate the effect of the root absorption of NaCl solutions, a screening with six evergreen species was performed: Viburnum tinus, V. davidii, Elaeagnus pungens, Berberis candidula, Pyracantha coccinea and Ligustrum ovalifolium. The effect on the leaves yellowings and necroses, connected to the root absorption of NaCl solutions at concentrations of 0.25 N, was very evident in the case of Viburnum davidii, Berberis candidula and Pyracantha coccinea. Viburnum tinus, Elaeagnus pungens and Ligustrum ovalifolium on the other hand showed little damage. INTRODUCTION In past centuries the presence of snow and ice was less of a problem, because people travelled less and a sleigh was used to cross long distances. In 1880 in Paris, sodium chloride was used as antifreeze for the first time. Today, sodium chloride is the most widely employed de-icing salt in the world. Although it is essential to grant safety on the roads in winter, it has a strong impact on vegetation, soil, and animals. When plants are grown on the sides of roads, their tolerance to salt must be considered. In towns the necessity to use plant species resistant to salinity has encouraged researchers in different parts of the world to study the effects of different saline substances on plant species and the tolerance mechanisms of the plants. Different plant species show different tolerances to the increase of salt concentration: while much it is known about the behaviour of trees (Headley and Bassuk 1991), the literature on shrubs is scanty. Salt resistance or sensitivity are influenced by genetic factors, soil temperature and vegetative state of the plants. Francois and Clark (1978) determined the tolerance to salt of some shrub species submitted to saline treatments with sodium chloride and calcium chloride. Abelia grandiflora, Mahonia aquifolium and Photinia fraseri showed little tolerance, with a growth decrease in relation to high salinity. Dirr (1975), used salt solutions with different concentrations (CaCl2, NaCl, KCl [potassium chloride], Na2SO4, K2SO4 [potassium sulphate]) on Hedera helix, and found out that Clcauses damage by direct toxicity, provoking wide foliar necroses, whereas Na determines a change in the osmotic potential of the soil, limiting the water and mineral absorption. MATERIALS AND METHODS The experiments were carried out in the glasshouses at the Experimental Centre of Proc. IC on Urban Horticulture Eds: R. Junge-Berberovic et al. Acta Hort 643, ISHS 2004 154 the Agricultural Faculty of University of Turin at Carmagnola. First Experiment Cotoneaster salicifolius 'Repens' shrubs were subjected to 11 dippings in the different salt solutions every week. The research protocol foresaw the use of a control (water) and three salt solutions (NaCl, CaCl2, Na2SO4) at two different concentrations (0.25 N; 0.125 N). Each treatment was made on nine plants of Cotoneaster salicifolius. The height above the collar, the diameter and the number of shoots of every plant were determined. A visual damage classification was attributed to the plants. The leaves of all nodes of the longest branch and the leaves of the nodes of the first two branches of all plants were taken into consideration. The leaves of each node were included in one of the following 5 classification categories: Category 1 healthy leaf Category 2 not so healthy leaf Category 3 unhealthy leaf Category 4 dry attached leaf Category 5 dropped leaf During the trial with Cotoneaster salicifolius 'Repens' four checks were made. Second Experiment This experiment concerned plant species interesting for their use in guardrails, slopes, street edges and sides, where the problem of salinity is more intense. A “screening” was made to obtain a first score of the resistance to salinity of six different shrub species: Berberis candidula (Fam. Berberidaceae), Viburnum davidii (Fam. Caprifoliaceae), Elaeagnus pungens (Fam. Elaeagnaceae), Ligustrum ovalifolium (Fam. Oleaceae), Pyracantha coccinea (Fam. Rosaceae) and Viburnum tinus (Fam. Caprifoliaceae). The plants were grown in 9 to 18 cm diameter pots and were placed inside a cold glasshouse. Trials were made to evaluate the effect of the root absorption of NaCl solutions at concentrations of 0.25 N. The treatments with a salt solution of sodium chloride 0.25 N were repeated every fortnight. At every treatment the plants were dipped for 5 minutes into the salt solution, in order to completely soak the pot of soil.