The Amish around here, use T-posts for stakes in their many, many greenhouses.

One thing NOT to do is attach strings to the greenhouse frames in the wrong spots. I had a friend years ago that did and bent the frame. Don't know how they did it, but it happened.

Marla

i use twine and clips on some and weave some others. generally we weave determinants and use twine/clips on indeterminants. but i don't get them from johnnys where everything is over priced. i got mine from berry hill drip.

T-Posts, baler twine (sisal). We use the Florida weave. T-Posts are strong enough where you can put one every 5-6 plants instead of every plant. If you use wood, the weight of a 5-6 loaded tomato plants can snap a wood stake, especially if it is in the field and it gets a little windy. I know some people will scoff at sisal, but I hate removing nylon twine at the end of the season. With sisal, I can just cut where I want and if pieces fall in the field, they get plowed under and decompose in a year or two. Nylon is forever, at least in terms of our lifetimes.

I spoke to a an older grower who lamented that he did not start with T-Posts when he was my age (34). He said he has paid the cost of wood many times over compared to T-Posts.

T-Posts are WORK to install if you are doing it by hand. My son and I put in 125 last night. It WILL give you a workout.

You did not say what SIZE greenhouse you are growing in. A 16x24 is a lot different than a 30x100.