In the beginning, you may even want to start your seed directly in the final container, simply by putting it one inch deep, pointy end down. It is surprising to some how often this works, even though mother nature does it all the time. If you go this route, lightly mist the area around the seed several times a day with 5-10 good squirts, attempting to only wet down as far as that seed. Continue this until the seedling hits the surface.
Keep using the spray bottle twice a day, now attempting to give enough water to soak in to roughly 3x the plant's height, and in a circle out to 3x the plant's diameter, by at least doubling the amount of squirts you gave to the seedling. Do not soak the entire container right away.... your new seedling cant handle that much water and if the seedling starts to wander or swim in the wet soil, you are giving too much.
Water like this, with these relatively small amounts a couple of times a day, always attempting to get a good part of that water out away from the trunk of the plant, by trying to make the outside edges of that circle 3x the diameter of the plant, the wettest places in the container.... you are attempting to entice the top roots to grow out in that direction.
After the plant has gotten a couple of leaves and gotten taller, it will no longer swim around in the soil if given a lot of water, and it is time to get a bit more aggressive than the spray bottle can do... it is time to move to the watering can and a couple of cups of water at first, slowly soaking the entire top surface of the container. We aren't trying to saturate the container yet, but we do want enough water to soak into the entire surface at least 3x the height of the plant, and we want some of that water to head straight down the middle, where the roots are trying to reach the bottom. This is when it is handy to have been an outside vegetable gardener, so that you know how to test the top of the soil to see if it is moist. When you can no longer feel moisture a day or two later, water like this again.
When the plant's 3x diameter reaches the outside edges of the container, water the entire container slowly, to saturation (runoff) for the first time. It will take a week or more for the plant to use all of that water on this first round, but you don't want the plant to sit idle all of that time either, or it will stagnate. It is time to change the watering pattern again.
Every 3 days or so do a partial watering of the top of the surface, again with only enough water to soak in to the first 3 or 4 inches of soil. Two specialized sets of roots are now forming, the top spreader roots designed to choke off other plants and quickly gather up rain, and the bottom tap and feeder roots. You are attempting to water only the top spreader roots, while the bottom tap/feeder roots continue to work on the water sitting in the bottom of the container for as long as it takes to clear that first full watering.
You may have to do this secondary top watering 2 or 3 times while you wait for the container to dry out all the way to the bottom. Force the plant to grow the necessary roots to do this job by being patient, and the plant will eventually use all of that water. Once the lift method, a dip stick or a moisture meter tells you that is is finally dry down to the last inch of container, it is time to water completely again and repeat the process, while every 3 days watering the top, until the bottom finally syncs up with the top.
Every time you go through one of these cycles, the roots will get stronger and the time between complete waterings will diminish. Eventually the top and the bottom will sync up and you will not have to do the secondary watering any more, you will just be watering the whole container every 3 days or so, as the wet/dry cycle stabilizes at around 3 days.
It is important to cycle the plant like this all through veg so as to force the plants to develop a solid root ball... the roots do not grow to fill that container unless you challenge them. Once you get into bloom, it is time to change your watering strategy.
From then on your goal is not building roots, it is time to really start using the roots that you have carefully built. Your goal at the end of stretch should be to start pumping as much water/nutes into the plant as it can take. I typically will force a plant that is perfectly happy with a 3 day wet/dry cycle into an every other day watering all during bloom... and with the roots you have forced the plant to grow in Veg, they will be able to take just about as much water as they did in 3 days, if you have done this correctly.
Good Luck and Good Grows!
Emilya
