With that said, basil is still a very hardy plant and can usually handle being over or under watered.
Saving A Wilted Basil Plant
Basil thrives in warm weather and needs constant watering when it’s hot. So you forget to water your plant for a couple of days in the heat of the summer and the next thing you know, your plant is wilted and you think it is dead. More likely than not, your plant can be saved.
If your plant looks dead or wilted, it might be able to be saved. If you forgot to water the plant for a couple weeks, it might not be able to be saved. But if you forgot to water it for a few days, odds are you can save the plant.
Check the stems. If they are still green, and not brown, water the plant until the soil is damp. Over watering is OK in this situation.
After watering your wilted plant, place it in a sunny location and wait a few hours. There is not much else to it. If the plant can be saved, after an hour, the plant should start to respond to the watering.
Most of the leaves should begin sprouting back to life after an hour or two. The leaves are probably still weak and you can water again. If a few stems do not respond to the water, they can be pruned. After watering, wait another hour or two.
Your basil plant, which only hours ago looked dead and wilted, should be strong and healthy once again. Be sure to continue watering your plant to keep it healthy and repeat this process next time you forget to water your plant.