Foliar application of mineral nutrients considers a method of supplying nutrients to higher plants more rapidly than methods involving root application, which makes the nutrients more efficient. It is a quick and efficient method of supplying micro elements in particular. It can, also be used to satisfy acute needs of macro nutrients. This study was conducted on garlic cv. Sids-40, in the privet farm at Kafr Meet Faris village, near El-Mansoura, Dakahlia Governorate, during 2008/2009 and 2009/2010 seasons to study the effect of foliar application with certain magnesium concentrations (0.0%, 0.2%, 0.4% and 0.6% as Mg-citrate) either single and/or in combination with foliar application of some yeast extract concentrations (0.0, 25 ml/L, 50 ml/L and 100 ml/L) on plant growth, yield and its components, as well as chemical constituents and storability of bulbs during the storage period. The obtained results could be summarized as follows: In general, results showed that the plants sprayed with Mg-concentrations were better than those of the unsprayed ones. Increasing the foliar applied magnesium concentration from 0.2% to 0.6% Mg significantly increased plant height, number of leaves/plant, plant dry weight and bulbing ratio as well as total yield and bulb weight and diameter. Moreover, foliar application of magnesium at 0.6% Mg significantly increased concentrations of N, P and K in cloves. In addition, TSS% and volatile oils were increased. This concentration had the most interesting observation in the enhancing of storability. On the other hand, foliar application of yeast extract at 50 ml/L gave rise to significant increases in plant height, number of leaves/plant; plant dry weight, bulbing ratio, total yield, bulb weight and diameter and clove weight as well as chemical constituents in cloves and decreasing bulb weight loss percentage during the storage period compared with the other treatments. The combined treatments of Mg-concentrations and yeast extract were generally more effective on the most studied parameters than single ones. The best results were obtained by foliar application of 0.6% Mg with foliar application of yeast extract at 50 ml/L. This treatment achieved increases in yield at the end of the storage period reached to 18.20% and 18.80% in the first and second seasons, respectively compared with the untreated ones. Therefore, this treatment could be recommended for raising garlic yield and improving bulb quality during the storage period under similar conditions to this work.