Penelitian ini bertujuan (1) mengetahui perbedaan pertumbuhan tanaman bayam cabut (Amaranthus tricolor L.) akibat pemberian perlakuan dengan berbagai variasi konsentrasi ekstrak rebung bambu tali (Gigantochloa apus) dan (2) mengetahui konsentrasi ekstrak rebung bambu tali yang efektif untuk pertumbuhan tanaman bayam cabut. Jenis penelitian ini termasuk penelitian sungguhan (true experimental). Rancangan penelitian yang digunakan pada penelitian ini adalah The Randomized Post Text Only Control Group Design. Perlakuan yang diberikan terdiri dari satu variabel bebas yaitu, pemberian variasi konsentrasi ekstrak rebung bambu tali yaitu: 0%, 5%, 10%, 15%, 20%, dan 25%. Anlisis data pada penelitian ini menggunakan ANAVA satu arah dengan taraf signifikansi 5% dan dilanjutkan dengan uji Beda Nyata Terkecil (BNT). Hasil penelitian menunjukkan tanaman pada konsentasi ekstrak rebung bambu tali 25% memiliki biomassa tertinggi dengan berat kering 7,93gr, tinggi 49cm, jumlah daun 25,75 helai dari semua perlakuan, dan hasil Uji BNT menyatakan bahwa konsentrasi 5% merupakan konsentrasi yang paling efektif dengan beda rerata 0,80gr antara 0% dan 5%. Dapat disimpulkan bahwa terdapat perbedaan nyata pada pemberian ekstrak rebung bambu tali dengan konsentrasi yang berbeda.Kata Kunci : Konsentrasi, Amaranthus tricolor L., Gigantochloa apus, pertumbuhan. The purpose of this research were (1) perceive the difference of growth of edible amaranth plant (Amaranthus tricolor L.) due to treatment by given various concentration of string bamboo shoot (Gigantochloa apus) and (2) find out the effective concentration of string bamboo shoot extract to the growth of edible amaranth plant. This was a (true experimental) research with Randomized Post-Text-Only Control Group Design as the research method. The given treatment consisted of one independent variable that was, giving various concentration of string bamboo shoot extract, such as 0%, 5%, 10%, 15%, 20%, and 25%. Data analysis in this research used one way ANOVA with significance level of 5% and was continued with the test of Least Significance Different (LSD). The results showed that the edible amaranth plant at the concentration of 25% string bamboo shoot, had the highest biomass with dry weight of 7.93 gr, height 49 cm, leaves number in amount of 25.75 strands, from all the treatments, and BNT testing showed that most effective amount of concentration used was at 5% with average different of 0.80gr in ratio 0% and 5%. It can be concluded that there was significant difference in giving string bamboo shoot extract with different concentration on the growth of edible amaranth plant.keyword : Amaranthus tricolor L., concentration, growth, Gigantochloa apus.