The ability of tomato plants to withstand flooding depends on how quickly they recover after the stress ends. Flooding causes damage to the plants' primary roots and replacing the damaged root system with new roots after the floodwaters recede is crucial. We looked at how promoting the growth of new roots through hilling affects growth and photosynthesis resumption in tomato plants after flooding. After a period of partial submersion, we drained the water and allowed plants to recover with or without hilling treatment. Hilling treatment consisted of applying moistened soil to the base of a group of plants immediately after water drainage to prevent new roots from drying out. Another group of plants was left with their stems exposed to the air. Control plants were kept under the same conditions but were watered regularly. We measured various parameters, including biomass allocation, nitrogen concentration in leaves, transpiration rate, stomatal conductance, net CO₂ assimilation rate, intercellular CO₂ concentration, and chlorophyll fluorescence, throughout the post-flooding period in control, hilled, and non-hilled plants over a six-day recovery period. Flooding stress significantly reduced plant biomass, but root growth resumed faster in hilled plants, reaching normal levels three days after the stress. Nitrogen content in leaves also recovered more quickly in hilled plants, showing that their root absorbing capacity resumed faster. Additionally, leaf gas exchange, carbon assimilation, and photochemical efficiency were restored in a shorter time in hilled plants. Our findings suggest that promoting root regeneration is crucial to aid recovery from flooding in tomato plants, as promoting stem-borne new root growth speeds up photosynthesis and biomass gain.