Using a sturdy, wheeled cart makes hauling bulk purchases and heavy objects (melons, winter squashes, citrus) much easier to handle.
A good one can carry up to 100 pounds (that's a lot of tomatoes!) and folds down for easy storage once you're home.
Some such carts are made of meshed wire—metal cages to hold your bags. Those tend to be the sturdiest versions but require the use of bags or other containers to keep most produce items from rolling out.
Others, such as the one in the picture here, have fabric sides. These tend to be able to carry a bit less weight than heftier metal versions, but they have the bonus of being lighter to carry or pull, and better able to contain all of your purchases without risk of them rolling onto the sidewalk.
How to Choose the Right Cart for You
As with most things in life, you can't have it all with a foldable utility cart. Here are the basic options you need to consider:
Weight vs Capacity: The sturdier the cart, the heavier it is likely to be. If you're considering one for farmers market shopping and you do a weekly shopping for all of your produce, picking up meat, dairy, and other heavy items, too, you'll want to go with heavier, more solid carts. If, on the other hand, you make more frequent visits or just pick up a few specialty items when you go, a lighter-weight cart may be all you need.
Weight vs Wheels: As with carrying capacity, solid, sturdier wheels that make pulling the cart easier will add weight to the cart, making them heavier to move around even as it's easier to pull.
Open vs. Closed: As mentioned above, metal cage-type carts tend to be able to handle more weight, while fabric-sided options are lighter weight but also can only handle lighter weights.
No matter what kind of cart you choose—or if you just keep using a stroller even as the kid(s) out-grow it—be mindful of how you wield it around the market. Always push carts in front of you so you can see when you might hit someone, give right of way to those without carts, stay with the cart (don't park and shop!), and don't stop in the middle of crowded walkways. Recognize that with a cart you're taking up more space than those without them!