Sometimes chairs just aren't made to be outside....often the makers use cheap glue. You could try gluing them back together with either Wood glue or even caulk or liquid nails.

If you want a good garden chair you get some with a removable seat.
Carmen

Being they fell apart that fast they certainly would not last well as outdoor planters. Maybe they can be re-purposed into something else.

I had one chair that has held up outside so I just finished this. It is planted with wintersown wave petunias.

Love the color of the purple chair. I used Gorilla Glue to glue a couple of old chairs and so far they've held together well.

I use Carpenter's Wood glue for all the antique chairs & table I put back together but they are inside. Hubby used it on all wood inside & out & nothing ever fell apart but of course in CA. it isn't very cold & no snow(yet-still hoping for a quick pic of snow at my house) I love your chair, will look great with the wave petunias flowing over it!! What color are they? TFS Jan

Since it will be outdoors and holding plants, why not just drill some holes and screw the pieces together?

A few years ago I purchased an old chair with the intention of making it into a chair planter. I just started working on it yesterday. (I know that's terrible, just too many things going on.) Anyhow I noticed that the previous owner had used barb wire under the seat to help secure the chair. It sounds dangerous but it's going to be a planter and not a chair that a person would sit on. I actually like the rustic look that the barb wire gives it. I'll try to post a pic when I finish the project.

a girl named Max- wow, I've heard of lot of things in chairs, horsehair, springs, cotton padding, newspapers in middle of caned seat from 1930's still in good shape. Barb wire is a first! Love to see pic of it when you are finished with it. I love the purple one pictured above. Jan

I would try and strengthen the joints if possible with screws. Pilot drill the joints when its dry. Make the screw holes big enough to let the screw go in easily but not big enough that they don't get a good bite to deal with the changes in temperature as the wood expands and contracts.

If you're able to glue them back together and put in some screws then sand lightly and paint with a good outdoor grade latex. Put on at least two coats. This will protect the wood and the joints from the weather. Paint the feet too. And when you set it out in the yard try to put it in a location where the feet won't be sitting in water. They should last several years.

Use the molded dowels to make bugs or dragonflies etc,--
don't throw them away!
Even the back pieces that are rounded can still be used for
wind chimes, or put cup hooks on and hang your trowels and
other tools.
I, too have trouble with wooden things with all of the rain in Florida.
I clear coat a lot!!! Even on my rusty things.....

Has anyone come up with a paint that will really preserve wooden chairs?
My neighbors and I had a big yard sale and her chairs (mostly seatless) didn't sell and the thrift store wouldn't take them.
I would like to paint them up and use them as plant holders, but as of now, chairs only last a year or 2 outside. Nancy