When & how much to Water
There two tricks for knowing when your plant needs water. Unfortunately, these don’t work for gauging seedlings. But seedlings are pretty easy to water and really you just want to aim for the top always being slightly moist. The root system is probably around the same size as the plant so just imagine the seedling flipped upside down and think about how much water would be needed to surround it.
Two methods to determine when to water
First method: After watering don’t water again until the top of the soil is dry, which is about an inch or two down or up to your first knuckle. I used this method in the beginning and preferred it until I became more comfortable with method two.
Second method: Feeling the weight of the container. Watering will cause the container to become much heavier than when it’s dry, which is good for the plant. You don’t want your grow medium to always be saturated. This is another reason I recommend a container when growing outside. I think it took me until my third or fourth grow before I completely switched to this method. And it develops naturally because my friend would use that method and I just couldn’t understand how when I was on my first grow.