IME eBay has some of the best bulk pricing on the supplies you are looking for. Just be sure to check the shipping costs as they will sometimes jack up the shipping to make up the low price on the supplies. But there are still some good bargains to be found.

Novosel Enterprises is another good source - price wise - and they carry everything. Then there is Farm Tek Grower's Supply, ASC Argi Supply, just to name a few. Even most of the common seed companies will carry basic seed starting supplies. Google 'seed starting supplies' for lots of links and prices.

You can also use the common plastic drink cups in various sizes. Many do. You'll find discussions about other seed starting suppliers over on the Growing from Seed forum here.

Dave

Fedco has better prices for trays (for smallish numbers) than some of the other seed vendors, IIRC. And you can buy bottom trays and mesh trays individually. They're in the non-seed part of the Fedco catalog, which you can purchase from year-round.

The disadvantage of using drink cups (I use WM's 16 oz. colored cups) is the need to cut holes in the bottoms. But that's the sort of mindless task that -- after putting it off -- when I finally sit down and do it, I'm disappointed when I reach the end! IIRC, some people use a wood-burning tool (or whatever) to burn the drain-holes? I just use kitchen scissors and cut 3 smallish V's in the bottom edges.

I buy in volume from http://www.mortonproducts.com/

DarJones

I also like Novosel. They have extra-deep 3-1/2" square pots that are great for tomatoes, and fit perfectly in a standard tray.

Here is a link that might be useful: Novosel square pots

You might try Craig's List. Some people prefer to give them away rather than sending them to a land fill.

I share a lot of plants, too and often ask for the pots back.

These last few years, I've been starting my toms in styrofoam coffee cups. If I need to pot them up before putting them out, they go in solo cups. It's worked great.

Interesting how many people start lining up when something is free. Just tell the people there will be no plants this year because you are out of pots. Watch the pots pour in.

I have done the same for the last 2 years, and last year grew about 100 seedlings and gave away about 90, since I only have room for 10 or 12 in my garden. I used the generic little white plastic drink cups from Walmart the size of "dixie" cups to start them (about 1.50 for about 200) and potted them up into large drink cups. I used Solo the first year and hefty last year because they were cheaper. I used a sharpie to write the variety directly on the cups. Warning, don't know why, but last year the sharpie washed off the hefty cups after I put them in the garden. When I used the solo brand, I planted into the garden then put the cup right next to it and filled it with soil to weigh it down and pushed it into the soil a little and they stayed put the entire season. Just a reminder, I use a nail to punch a few holes in the the bottom of each cup, and by stacking the cups I can punch through several at one time. I am trying to keep the cost down as much as possible since I don't ask for money for any of these. Now if I can just find a less expensive place to buy seed starting and potting mix! Even at Costco and Walmart prices filling 100 solo cups takes quite a bit of mix.

Oops, sorry this doesn't really answer your question about where to get 3 1/2 pots, but you might consider other containers if you can't find a good enough price. :)

This post was edited by sue_ct on Fri, Feb 1, 13 at 14:19

I don't want to hijack the "thank you" thread, but do want to point out that Novosel has free shipping on orders over $75, and also has discounts (increasing)on orders of $100 or more.

try FREECYCLE in your area

I tend to agree with garf

Maybe a quick email to your 125 friends asking for some starter pots might ought to be the way to go.

A friend of mine makes homebrew beer. His policy: if you want a refill, you'd better figure out a way to get him some bottles :-)

Go to church: A Ham and Bean Supper. They always fill up a barrel with styrofoam coffee cups. Take them home, rinse and plant. You might even rinse them off in the church kitchen! I can attest to the fact that tomato seedlings do very well in them and you can't beat the price. I learned of this trick from Roger Swain of PBS Victory Garden program some years ago.
Victor

Go to church: A Ham and Bean Supper. They always fill up a barrel with styrofoam coffee cups. Take them home, rinse and plant. You might even rinse them off in the church kitchen! I can attest to the fact that tomato seedlings do very well in them and you can't beat the price. I learned of this trick from Roger Swain of PBS Victory Garden program some years ago.
Victor

I always save plastic drinking cups, styrafom cups, cottage cheese, yogurt, sour cream, etc containers throughout the year. I also have a paper pot maker that makes decent newspaper pots for smaller 4-5 week seedlings.