What's a good dense plant that will choke out weeds?

Hi there, I suggest you cALL INTO YOUR LOCAL PLANT CENTRE and ask them what they can suggest you plant as they will be suitable for your area.............

John has a good suggestion.

A plant to avoid would be a climber like a Morning Glory. Creeping Charley is somewhat lower, but can extend it's vines and choke everything.

Although they have beautiful blooms, they soon become bullies and spread like crazy.

You might be thinking of a low ground hugging plant that will not take over, for this visit your local nursery.

I don't know your zone, but day lilies will get thick and bloom-they will go down in winter-check with your local garden center

Creeping Thyme comes in several colors,low growing,gets thick enuf to be used as walkway - Would you like a perennial ground cover plant that is an evergreen, very little maintenance and smells good;how about this plus-Lemon Creeping Thyme a good ground cover and mosquito repellent? the Creeping Thyme cultivars......More than 150 thymes are commercially available, with hardiness ranges from USDA Hardiness Zones 2 (–50°F) to 10 (30°F). Most are hardy to Zone 5 (–20°F) with winter protection. , which present a wealth of choices for unusual, aromatic ground covers. They are separated into two groups: Prostrate, which grow less than 3 inches high and resemble lush, sun-loving mosses; and Mounding, which form green or silver carpets that are more than 3 inches high. here's much more info. https://www.finegardening.com/article/thyme-the-fragrant-ground-cover