Hostas are a hardy plant that can withstand periods of drought, but they will start to wilt and look unhealthy if they go too long without water. In general, hostas need about 1 inch of water per week during the growing season. If you let the soil around your hostas dry out completely, you may see the leaves start to turn brown and collapse. To avoid this, make sure to give your hostas a good soaking every few days during hot summer weather.