Homogalacturonan (HG) is a chemically and spatially dynamic pectic cell wall component whose methyl-esterification patterns significantly influence wall biomechanics and plant development. Despite the availability of specific mAbs, tools for tracking HG in its native context within live tissues remain limited. We developed a novel peptide-based probe (Lys10) that recognizes negatively charged, demethylated HG through strong anionic interactions. Specificity analysis with a dot blot assay confirmed its binding to HG, with signal intensity inversely proportional to the degree of methyl esterification. Molecular docking and molecular dynamics simulations further supported a stable, high-affinity interaction between Lys10 and HG. The calculated Kd was comparable to that of antibodies. Externally applied Lys10 quickly penetrates live tissues, enabling live-cell imaging of cell wall HG in roots. Using Lys10 for time-lapse imaging of root hair elongation, we observed rapid redistribution of the signal between the tip and shaft, indicating localized HG remodeling during tip growth. To explore the possibility of developing a genetically encoded marker, we generated stable Arabidopsis lines expressing HG-binding oligopeptides fused to mCherry and targeted to the secretory pathway. Overall, our results demonstrate that Lys10 is a versatile HG-recognition tool with potential for long-term, real-time imaging, facilitating studies on HG dynamics.