25ml of liquid water takes 3 hours to completely boil off under vacuum. Less if the water is mixed in with other substances (eg. soil). The inner structure of the plant itself is capable of trapping water to an even greater extent. To the point where water directly boiling off the plant directly isn't significant.
Note that this was simulating asteroid conditions. Mars is slightly better at retaining water since it has slightly more pressure. This is why it's pretty likely that we're seeing flowing water on Mars each summer: https://www.nasa.gov/press-release/nasa-confirms-evidence-th...
25ml of liquid water takes 3 hours to completely boil off under vacuum. Less if the water is mixed in with other substances (eg. soil). The inner structure of the plant itself is capable of trapping water to an even greater extent. To the point where water directly boiling off the plant directly isn't significant.
Note that this was simulating asteroid conditions. Mars is slightly better at retaining water since it has slightly more pressure. This is why it's pretty likely that we're seeing flowing water on Mars each summer: https://www.nasa.gov/press-release/nasa-confirms-evidence-th...