It does sound like excess water may have been a problem for you. Those plastic lids are great for keeping the soil evenly moist, while you wait for the seeds to germinate. Once I have plants up, I remove them and let the plants have some air.
It's also important for the pots to not be sitting in water, whether they're made of peat or plastic. Most flats have a gridded bottom with channels for water to flow down into, but you can still flood the flat and plant roots if you over water and the water rises above the level of the grid. If you pick up one of the pots or 6-packs, you see how much water is in there. If you have the space, you can also just leave a corner empty, so you can always see what's going on down there. If it's too flooded, you can take the pots out to empty it or try a turkey baster to remove the excess water. As an example, an 1/8" of excess water above the grid can evaporate, with the lid off, but if it's an inch deep, that's too much water.
Pots can also be set on raised cooling racks like you use for baking, to provide drainage. You can also put gravel in a tray or saucer to keep pots out of water.
A capillary system for watering sounds like a great idea for you! I've seen those in some of my gardening catalogs and on internet sites. I know a couple of gardeners online that have had success with them. Once you get them set up, I think it could provide more even watering for you. I don't know if particular pot styles or planting mediums work better than others for that.
When it gets closer to planting time, I start moving plants outside when it's warm enough, to harden them off. They don't go right from the indoors to full sun outside, as it can be too much for them. Some people put them out for part of the day and bring them back inside. I have a spot where they get morning sun and then shade that works for me. That way, they can stay out all day. If the weather is warm enough, they can be outside at night, too. If it's going to be too cold, I bring them back inside.
When I put the plants outside, I switch from fully enclosed flats that contain water indoors, to flats that have drainage holes, like you see at the garden centers. Actually, mine are just flats I've saved from when I've bought plants in the past, although you can also buy them. This allows me to water the plants freely outside with the hose and not worry about water collecting in the bottom. I actually have flats with drainage holes that fit inside flats that don't have drainage holes. I love that, for making it easy to move things in and out in the early part of spring, when the weather is so erratic.
It's also important for the pots to not be sitting in water, whether they're made of peat or plastic. Most flats have a gridded bottom with channels for water to flow down into, but you can still flood the flat and plant roots if you over water and the water rises above the level of the grid. If you pick up one of the pots or 6-packs, you see how much water is in there. If you have the space, you can also just leave a corner empty, so you can always see what's going on down there. If it's too flooded, you can take the pots out to empty it or try a turkey baster to remove the excess water. As an example, an 1/8" of excess water above the grid can evaporate, with the lid off, but if it's an inch deep, that's too much water.
Pots can also be set on raised cooling racks like you use for baking, to provide drainage. You can also put gravel in a tray or saucer to keep pots out of water.
A capillary system for watering sounds like a great idea for you! I've seen those in some of my gardening catalogs and on internet sites. I know a couple of gardeners online that have had success with them. Once you get them set up, I think it could provide more even watering for you. I don't know if particular pot styles or planting mediums work better than others for that.
When it gets closer to planting time, I start moving plants outside when it's warm enough, to harden them off. They don't go right from the indoors to full sun outside, as it can be too much for them. Some people put them out for part of the day and bring them back inside. I have a spot where they get morning sun and then shade that works for me. That way, they can stay out all day. If the weather is warm enough, they can be outside at night, too. If it's going to be too cold, I bring them back inside.
When I put the plants outside, I switch from fully enclosed flats that contain water indoors, to flats that have drainage holes, like you see at the garden centers. Actually, mine are just flats I've saved from when I've bought plants in the past, although you can also buy them. This allows me to water the plants freely outside with the hose and not worry about water collecting in the bottom. I actually have flats with drainage holes that fit inside flats that don't have drainage holes. I love that, for making it easy to move things in and out in the early part of spring, when the weather is so erratic.
