This study investigates the effect of graduated salinity irrigation on the growth and flowering of Grey Mangrove Avicennia marina seedlings within a controlled nursery environment in Tajoura, east of Tripoli. Total Dissolved Solids (TDS) concentrations ranged from 103.4mg/L to 30,000mg/L, alongside continuous monitoring of pH and electrical conductivity (EC) to simulate dynamic saline environments, such as Farwa Lagoon. The results demonstrated a high salt tolerance capacity in the seedlings, exhibiting only a slight delay in flowering compared to counterparts cultivated in the United Arab Emirates. Furthermore, a progressive improvement in vegetative growth was recorded with increasing salinity levels, suggesting a positive acclimatization capacity of the studied species and potentially its physiological requirement for specific salinity thresholds to achieve optimal performance. The findings highlight the critical importance of graduated irrigation in mitigating salinity stress during seedling hardening, as well as the pivotal role of silty sand soil (SM classification) in supporting growth, while underscoring the need to enrich organic matter content to optimize water and nutrient retention. This study builds upon and extends previous research conducted on 28 mangrove seedlings under Libyan environmental conditions, strongly supporting the viability of Grey Mangrove cultivation along the Libyan coastline, particularly in hypersaline environments, provided meticulous irrigation and growth management are applied. This scientific manuscript was presented at the sessions of the International Renewable Energy, Gas, Oil and Climate Change Conference "iREGO" in the period of April 25-27, 2026. Tripoli - Libya............ Keywords: .............Grey Mangrove, Salinity Stress, Plant Acclimatization, Libyan Coastline, Graduated Irrigation.