Agroforestry system has potential to increase the overall yield, it essentially create competition among the components for resources in addition to presence of allelochemicals in either of the component which has impact on productivity. Therefore, detailed studies on the effect of tree allelochemicals on seed germination, growth and metabolism of crop plant need to be conducted prior to recommending any tree species for agroforestry programme. The present investigation entitled “Allelopathic Effect of Three Agroforestry Tree Species on Germination and Growth Pattern of Traditional Crops of Garhwal Himalaya” was undertaken in the Department of Forestry, College of forestry (V.C.S.G. Uttarakhand University of Horticulture and Forestry) Ranichauri, Tehri Garhwal, Uttarakhand, during August 2015 to June 2016.The study was conducted to see the allelopathic effect of two native tree species (Celtis australis, Quercus leucotricophora) and one exotic tree species (Robinia pseudoacacia) on five agricultural crops (as a test crop) viz, Triticum aestivum, Hordeum vulgare, Brassica rapa, Lens culinaris and Vigna umbellate. The allelopathy expriements was conducted in laboratry and nursery by using CRD. The outcome of the study revealed that the germination responses in terms of different extracts of leaf and bark of tree species showed that the maximum average seed germination percent varied to great extent irrespective of different leaf and bark extracts. Brassica rapa was most resistant to leaf and bark extract than Triticum aestivum, Hordeum vulgare, and Lens culinaris while, Vigna umbellate was most sensitive. The result showed that allelopathic influences are species specific and extracts can have different influences on seed germination, root and shoot growth, MGT and GI of test crops. Both leaf and bark extract showed minimum mean germination at higher concentrations while maximum mean germination index were found in lower concentrations. Maximum root length was attained at lower concentrations whereas maximum shoot length was attained at higher concentrations. From the study, it can be concluded that for better agroforestry management, identifying local tree crops with a minimum accumulation of toxins in the soil is necessary. The inhibitory effects of leaf leachates has to be considered before recommending any species for agroforestry planting programme. Hence efforts should be made to select the species with the least allelopathic activity.