I used clear plastic containers last winter and the seedlings didn't do nearly as well as the ones in the milk jugs. I won't be using them again.

The main concern in containers is the depth. A soil depth of 3-4 inches is ideal so that should make you decide. I used some of the berry clear plastic containers my first year and not only do the roots not have enough space for development, but they dry out so quickly in the spring you need to water sometimes several times a day. If you have the time to watch them closely all day, you can go ahead and use them, but deeper is much better and easier on you.

I found the main concern for me when I tried these was moisture. Those berry and cherry-tomato containers have a lot of openings in the bottom, and I found them drying out more quickly than other containers. I ended up covering some of the holes with tape, and that worked. I suppose if you do that right when you are sowing (instead of waiting till the containers are outside in mid-winter and you have to go kneel on cold hard asphalt and rip tape and apply it with frozen hands) it may work for you.

Some of the smaller berry containers may be a bit shallow, as northerner says, but I think the larger ones (strawberries, for instance) may work, again if you deal with the openings. They certainly are convenient - holes in the bottom, attached lid - *almost* a perfect WSing container!

Almost, because the other thing is that there is not a lot of headroom for the seedlings in most of these containers. If you are like me and neglect everything, you may want to choose a container with more headroom, because you may end up removing two-foot-tall plants from your containers!

Dee

When I used these they dried out quite badly. I dont use them anymore either.

I tried big and little berry containers and found they had too many holes and dried out way too fast. But I have great luck with clear plastic salad bar containers and do many different seeds in them. There are a few that are too shallow, but most you can fill with 2 1/2 - 3 inches of soil by hilling the soil.

I make a couple of holes for drainage by running a fat drill bit (in the drill) through a stack of the containers in a couple of places on the outer edges. Or I cut drainage holes with an exacto knife-one on each side in the raised lip that many of the containers have to make it easy to bottom water later, if I need to.

Fill with soil, broadcast the seed, add an id stake, close the lid, and cut two or three ventilation holes in the lids. Outside they go.

One thing I really like about the salad containers is that they are so easy to open and close if we have a really hot early spring like we did this year.

I use the large salad boxes too, although generally divide them in half or 3rds and plant several varieties of seed. Then I discovered that they are great containers for raising butterflies, so most of mine are instead being used for that purpose!

I've tried a couple of the berry type containers and they worked okay. If drying out is a problem, you could line them up in a flat or plastic box with no holes, to bottom water and hold moisture. That's what I do with all the Solo and assorted other cups I use for spring sowing.

I think it is fun to tinker with containers from the supermarket that might otherwise be trash. When I had a greenhouse I did this a lot and found most were not deep enough unless one transplants seedlings to a deeper container while they were still quite small.

I have used clear plastic salad and cherry tomato containers for years - for containing square paper pots made of TP rolls and filled with moist potting soil. I can tightly fit 9 paper pots in the bottom halves of tomato containers and 12 in the salad ones, they stay nice and moist that way.
The containers with paper pots go in large translucent plastic containers with lids, that have enough headroom for the seedlings. I am very happy with this arrangement.