Slow Cooker Vegetable Soup

Jump To Recipe by Liz Thomson July 27, 2023 This post may contain affiliate links.

This hearty vegetable soup is made in a slow cooker for a delicious hands-off meal. This vegan soup will become a family favorite in your Crock-Pot!

Why I Love This Recipe

I love making vegetable soup and lately, I’ve been making it in my Crock-Pot. I like that this recipe is hands-off and the cooking time is flexible. It’s an easy “set it and forget it” kind of recipe. Plus, substitutions are easy based on what you have in your fridge and pantry.

You can enjoy this soup as a main dish or you can serve it as a side dish. Either way, it’s a great way to add lot of vegetables to your dinner routine! If you’re looking for more slow cooker recipes, try my slow cooker enchilada casserole or my slow cooker lasagna.

Ingredients & Substitutions

Onion: This adds flavor and depth to the vegetable soup. It provides a savory base and enhances the overall taste. If you don’t have a yellow onion, you can use a white onion or two shallots as a substitute.
Garlic: Minced garlic adds a pungent and aromatic flavor to the soup and it complements the other ingredients. If you run out of fresh garlic, you can use garlic powder as a substitute. Approximately 1/4 teaspoon of garlic powder can replace one clove of minced garlic.
Oregano: This adds a pleasant earthy, and slightly bitter taste to the soup. It helps to enhance the overall flavor profile. If you don’t have oregano, you can substitute it with dried basil or thyme for a different flavor profile.
Carrots: Carrots add natural sweetness and vibrant color to the vegetable soup. If you don’t have carrots, you can leave them out.
Celery: Celery has a mild, savory flavor that works well in soup. If you don’t have celery, you can omit it or add extra carrots for additional flavor and texture.
Bell pepper: A bell pepper adds a mild sweetness to the vegetable soup. You can substitute bell pepper with chopped zucchini or yellow squash if you don’t have bell pepper.
Diced tomatoes: Fire-roasted diced tomatoes add a smoky and slightly charred flavor to the soup. They also provide a rich and robust tomato base. If you don’t have fire-roasted diced tomatoes, you can use regular diced tomatoes or crushed tomatoes as a substitute.
Potatoes: Potatoes add a comforting and hearty element to the vegetable soup. If you prefer a lower-carb option, you can substitute potatoes with diced cauliflower or butternut squash.
Peas: Peas add a touch of sweetness and they’re a great way to add some extra fiber to this soup. If you don’t have peas, you can use frozen corn or green beans as a substitute.
Chickpeas: Chickpeas, also called garbanzo beans, provide protein, texture, and fiber to the vegetable soup. If you don’t have chickpeas, you can substitute them with white beans or kidney beans.
Pasta sauce: Pasta sauce adds depth, richness, and additional flavor to the soup. I like Rao’s tomato basil sauce or Barilla’s Vero Gusto tomato basil sauce. If you don’t have pasta sauce, you can use canned tomato sauce or crushed tomatoes as a substitute.
Broth: Vegetable broth serves as the base of the soup. I like Edward & Son’s “Not-chicken” style broth.

Variations and Substitutions

You can add additional vegetables like frozen green beans, canned lima beans, chopped fresh zucchini, and/or chopped fresh yellow squash. You could also add a handful or two of spinach just before serving.
For additional flavor, add a dollop of pesto to each bowl of soup or sprinkle freshly grated Parmesan cheese on top.
If you want to make a vegetable soup with lentils, try my slow cooker lentil soup recipe.

How to Make Slow Cooker Vegetable Soup

Combine the olive oil, diced onion, minced garlic, dried oregano, and a pinch of red pepper flakes. Microwave the mixture for about 3 minutes.

What to Serve with Vegetable Soup

This soup is delicious with a grilled cheese, but you could also try it with a broccoli sandwich for something a little more unique! A chopped salad, Beer Bread, or a crusty loaf of my Dutch Oven Bread makes a perfect companion to a bowl of hearty soup. If you love sourdough bread, consider a subscription to Wildgrain!

How to Freeze Vegetable Soup

To freeze vegetable soup, allow it to cool completely. Then portion it into suitable containers or resealable freezer bags, leaving some space for the soup to expand when frozen. Ensure a tight seal to prevent freezer burn and store in the freezer for 2-3 months. When ready to enjoy, thaw the soup in the refrigerator overnight and reheat on the stovetop or in the microwave until heated through.

Frequently Asked Questions

How do you add depth of flavor to vegetable soup? For this recipe, using a flavorful pasta sauce is a great way to flavor the soup. Another option is to add a Parmesan rind to the soup. It adds lots of savory, umami flavor. Remember that adding a Parmesan rind will mean this soup is no longer vegan. Remove the rind before serving.
Can I use frozen veggies in slow cooker? Yes! You can use frozen vegetables in this Crock-Pot vegetable soup recipe if you like. In fact, I have a frozen vegetable soup recipe that uses only frozen vegetables.
Why does my vegetable soup have no flavor? If your vegetable soup is lacking in flavor, be sure your seasonings are fresh and that your vegetable broth and pasta sauce have adequate flavor. Also, be generous when adding salt.
How long should you cook vegetable soup for? For this slow cooker vegetable soup recipe, you’ll cook the vegetables on high for 4-6 hours.

What size slow cooker do I need?

I used this large 8 quart oval-style Crock-Pot brand slow cooker, but any brand of slow cooker should work fine for this recipe. You’ll need at least 6-quart capacity to avoid overflowing and to ensure that the soup can cook evenly.

More Soup Recipes

If you’re looking for more vegetable soup recipes, try this 10 vegetable soup, frozen vegetable soup, or creamy vegetable soup. For more vegan soup options, try my vegan corn chowder, chili verde soup, or vegan wild rice soup.