I'm not very experienced with container growing, but I can say that squash generally kind of "sit there" until around the sixth week. Then, suddenly, they take off. Once they start they really go.

You could probably save money, in the long run, if in the future you purchase seeds instead of plants. Even the most measly seed packet will have enough seeds for your needs, for a couple of years, and you can save them in a desk drawer, etc. for that long. They will keep. Planting is a snap; even easier than planting the transplants. Just push the seed into the soil and inch. A seed will probably catch up with a transplant, no problem. (This is an aside from your question :)

George
Tahlequah, OK

Your problem is most likely that you used potting soil. You should have used potting mix. A subtle but impotant difference. Potting soil (for me at least) has a tendency to compact which is VERY bad for the plants. I use miracle grow potting mix for all of my containers. Potting mix is nice and fluffy and maintains a great structure all year. I grow tomatoes and peppers as well as minature bottle gourds with great success. I suggest that you never use potting soil in pots only potting mix.

Here is a quote about potting soil that I came across "In truth, just about anything could be called a potting soil -- low-grade compost, dirt and even ground up crates"

Since you have potting soil for next year try mixing shredded leaves and other organic material into the soil. If you do get potting mix it can be used for 5 years before you should replace it. I like to take all the soil out of my pots before I replant them and break up any clumps as a way to "fluff" the soil.

And I agree with George about the seeds they are the way to go for squash.

How large are your containers? Did you say they are in the same pot with some beans? Sounds like over-crowding to me. When I plant anything in pots, I use huge pots. I won't use anything less than 20 gallon pots for one tomato plant.
Mrs H