Zucchini and Yellow Squash Soup

Zucchini and Yellow Squash Soup has lots of flavor from rosemary and Parmesan and this tasty soup is perfect for fall! The zucchini soup can be made in the Instant Pot or on the stove, and it can easily be vegetarian if you use vegetable stock.

PIN the Zucchini Soup recipe to make it later!

I’m so happy to be updating the photos for this Zucchini and Yellow Squash Soup! I first made this when Lisa from Homesick Texan sent me the link to a zucchini soup recipe she had enjoyed. First I adapted the inspiring recipe to be lower in carbs. Then I made the soup right away because back then I’d just gotten braces on my teeth! Years later I’m still enjoying the Zucchini Soup, with nice straight teeth.

A few years ago, I added instructions to make this popular soup using the Instant Pot if you prefer that method. Or if you don’t have an Instant Pot you can easily make this zucchini soup on the stove.

And zucchini and summer squash will still be abundant for a few more weeks while garden season is winding down. I think using those summer veggies in a soup is a perfect way to transition into fall. I hope you enjoy the recipe!

What ingredients do you need for this recipe?

(This is only a list of ingredients; please scroll down for complete printable recipe. Or if you use the JUMP TO RECIPE link at the top of the page, it will take you directly to the complete recipe with ingredient amounts.)

• Olive Oil (affiliate link)
• butter
• yellow onion
• fresh minced garlic or Minced Garlic (affiliate link)
• Italian Herb Seasoning (affiliate link)
• Spike Seasoning (affiliate link), optional
• chopped fresh rosemary, or use a smaller amount of dried rosemary or Ground Rosemary (affiliate link)
• zucchini and yellow summer squash
• chicken stock (or use vegetable stock for vegetarian version)
• salt and fresh-ground black pepper to taste
• freshly grated Parmesan cheese, for serving (optional)

What if you don’t have fresh or frozen rosemary?

If you don’t have fresh rosemary or frozen rosemary, I would recommend using a much smaller amount of ground rosemary to flavor the zucchini soup. You can buy rosemary already ground, or grind some dried rosemary in a mortar and pestle.

Do you have to use Spike for this zucchini soup?

When Kara and I made this to take the new photos, we thought a small amount of Spike Seasoning added a nice flavor boost. But I’m listing that as optional, and the soup has been mega-popular for years without Spike.

What if you don’t have two colors of summer squash?

It will change the color a bit, but you can definitely make this recipe with all yellow summer squash or all green zucchini if that’s what you have. And actually if it was completely a yellow squash soup, I think that might be really pretty.

What Size Instant Pot Did I Use for this recipe?

I use a 6 Quart Instant Pot (affiliate link) for all my Instant Pot Recipes and that’s what I used for the Zucchini and Yellow Squash Soup!

How low in carbs is the Zucchini and Yellow Squash Soup?

When I was updating this recipe to add the new photos, I discovered that the nutritional information that had been on the site for this soup recipe was not correct. That info was first calculated when I moved my site from Blogger and had to calculate nutrition for more than 1,000 recipes! Hired assistants helped with that huge job, and we used the calculator that was built into my new website.

It was so upsetting when I realized the previous nutrition numbers for this recipe were wrong. I re-calculated it multiple times (using the newer built-in calculator on my site and several online ones). And I got very different numbers from the various nutrition analyzers I used this time. So I did my best to settle on numbers that made sense.

I don’t know why the original miscalculation happened or why I didn’t notice it for so long. The only good news was that this time the soup came out higher in protein on every calculator I tried. I’ve adjusted nutritional information in the recipe to show this soup with about 12 net carbs per serving, with 10 grams of protein. I removed the tag for Keto. I greatly apologize for the error and appreciate your understanding.

How to make Zucchini and Yellow Squash Soup:

(This is only a summary of the steps for the recipe; please scroll down for complete printable recipe. Or if you use the JUMP TO RECIPE link at the top of the page, it will take you directly to the complete recipe.

1. Finely chop fresh rosemary or frozen rosemary. (Or use a much smaller amount of dried rosemary. You can buy it ground or grind dried rosemary in a mortar and pestle.)
2. Also chop an onion, and mince a tablespoon of fresh garlic (or use minced garlic from a jar.)
3. Turn Instant Pot to Saute (or medium-high heat for stovetop soup pot.) 
4. Add olive oil and butter and heat until butter melts, then add onion and cook 3-4 minutes.
5. Then add finely chopped rosemary, minced garlic, Italian Herb Blend, and Spike Seasoning (if using.) Cook about 3-5 minutes more.
6. Add the chicken or vegetable stock and let it simmer about 10 minutes to flavor the stock. (Be sure to use the increased amount of stock if you’re cooking on the stove.) I used Saute for the Instant Pot, but on the stove I’d reduce the heat to medium.
7. While stock simmers, chop up zucchini and yellow squash to get about 8 cups of diced squash.
8. In the Instant Pot, add the squash, lock lid in place, choose MANUAL, HIGH PRESSURE and set the time for 5 minutes. When time is up, let pressure release for a few minutes, then use quick release method to finish.
9. On the stove add the squash and simmer over medium-low or low heat about 30 minutes. Cook until the squash is very soft and the flavors are well blended.
10. This photo shows how my squash looked after 5 minutes at high pressure.
11. I used my Immersion Blender (affiliate link) to puree the soup. You could do this in a food processor or blender, but be careful with the hot liquid.
12. Use the same process to puree stovetop soup after it’s cooked for about 30 minutes.
13. Then check the consistency of the soup, which will probably be too thin at this point. Simmer the soup to reduce it until it’s as thick as you’d like, about 15 minutes for the Instant Pot or 20 minutes on the stove. (I simmered on Saute in the Instant Pot.)
14. Here’s how my soup looked after it had been reduced.
15. Season yellow squash and zucchini soup to taste with salt and fresh-ground black pepper.
16. Serve hot, with plenty of freshly-grated Parmesan to add at the table if desired.

Make it a Low-Carb Meal:

The soup made with zucchini or yellow squash would be great as a meal with one of these low-carb breads:

• Olive Bread
• Low-Carb High Fiber Savory Muffins
• Almond Flour Pumpkin Muffins
• Savory Almond Flour Zucchini Muffins with Feta
• Savory Almond Flour Bread

Want more soup recipes that use zucchini?

Check out Amazing Zucchini Soup Recipes to see lots more tasty ideas for using zucchini in soup!

Weekend Food Prep:

This recipe for soup with zucchini and yellow squash has been added to a new category called Weekend Food Prep where you’ll find recipes you can prep or cook on the weekend and eat during the week!

Continue to Content

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4.5 Stars (58 Reviews)

Yield: 6 servings

Zucchini and Yellow Squash Soup

Prep Time 25 minutes

Cook Time 50 minutes

Total Time 1 hour 15 minutes

Zucchini and Yellow Squash Soup is perfect to welcome the arrival of fall! And you can make this zucchini tasty soup in the Instant Pot or on the stove or make it vegetarian by using vegetable stock.

Ingredients

• 2 T olive oil
• 1 T butter (see notes)
• 1 yellow onion, chopped
• 1 T minced fresh garlic (see notes)
• 2 tsp. Italian Herb Blend
• 2 tsp. Spike Seasoning (optional)
• 4 tsp. chopped fresh rosemary or frozen rosemary (see notes)
• 8 cups total zucchini and yellow summer squash
• 6 cups chicken stock (see notes)
• salt and fresh-ground black pepper to taste
• fresh grated Parmesan cheese, for serving (optional)

Instructions

1. Finely chop the fresh rosemary or frozen rosemary.(Or use ground rosemary or grind dried rosemary in a mortar and pestle.)
2. Chop the onion and mince the garlic (or use minced garlic from a jar.)
3. Heat olive oil and butter in the Instant Pot on the Saute setting, or use medium-high heat in a large heavy soup pot.
4. Then add onion and saute about 5 minutes, or until onion is translucent and softened.
5. Add garlic, rosemary, Italian Herb Blend, and Spike Seasoning (if using.) Cook 3-5 minutes more.
6. Add the vegetable or chicken stock to the onion mixture and simmer 10 minutes. For the Instant Pot I kept the setting on Saute to simmer the stock. I would use medium heat for the stovetop.  (Use 6 cups stock for Instant Pot or 8 cups for stovetop.)
7. While the onion, garlic, and rosemary are cooking, chop up enough zucchini and yellow squash to make about 8 cups of squash.
8. Then add chopped zucchini and yellow squash to Instant Pot or soup pot.
9. For Instant Pot lock the lid, choose MANUAL, HIGH PRESSURE and set the time for 5 minutes. When time is up, let pressure release for a few minutes, then use quick release method to finish.
10. For stovetop cooking,  turn heat to very low and simmer about 30 minutes, or until squash is soft.
11. Use an Immersion Blender (affiliate link) to puree the mixture, or use food processor or blender. (Be careful with the hot liquid if you’re using the blender or food processor. You might need to do it in two batches.)
12. When mixture is as pureed as you prefer, check the consistency of the soup.
13. Then simmer until the soup is reduced and as thick as you’d like it. (Simmer about 15 minutes on Saute in the Instant Pot. Cook for about 20 minutes on medium low on the stovetop. Cooking time may vary, depending on how thick you prefer it.
14. Season to taste with salt and fresh-ground black pepper.
15. Serve Zucchini soup hot, with freshly grated Parmesan cheese sprinkled on top if desired.

Notes

You can use 3 T olive oil if you don’t want butter.

Use minced garlic in a jar for this soup if you prefer.

Use any all-purpose seasoning if you don't have Spike, or skip it completely.

If you don't have fresh rosemary you can use a much smaller amount of ground rosemary (affiliate link) or dried rosemary ground in a mortar and pestle.

I use my homemade chicken stock but you can definitely use canned chicken broth or stock.

If you want this soup to be vegetarian use vegetable stock.

I used 6 cups of stock and slightly less than 8 cups of diced squash to make this in the Instant Pot.  You will need about 2 cups more stock for stovetop cooking.

Recipe inspired by soup recipe (no longer online) from Epicurious.com.

Nutrition Information

Yield

6

Serving Size

1
Amount Per Serving Calories 202Total Fat 9gSaturated Fat 3gUnsaturated Fat 6gCholesterol 15mgSodium 453mgCarbohydrates 17gFiber 5gSugar 9gProtein 10g

Nutrition information is automatically calculated by the Recipe Plug-In I am using. I am not a nutritionist and cannot guarantee 100% accuracy, since many variables affect those calculations.

Did you make this recipe?

Did you make this recipe? Please leave a star rating (under the PRINT button in the recipe) or share a photo of your results on Instagram! THANKS!

Low-Carb Diet / Low-Glycemic Diet / South Beach Diet Suggestions:
Zucchini and Yellow Squash do have some carbs, so this tasty soup has about 12 net carbs per serving, with 10 grams of protein when made with chicken stock. (This was originally calculated incorrectly; I apologize for that error.) This recipe would be suitable for the original South Beach Diet, but you might want to replace the butter with more olive oil. 

Find More Recipes Like This One:
Use Soups to find more recipes like this one. Use the Diet Type Index to find recipes suitable for a specific eating plan. You might also like to follow Kalyn’s Kitchen on Pinterest, on Facebook, on Instagram, on TikTok, or on YouTube to see all the good recipes I’m sharing there.

Historical Notes for this Recipe:
This recipe for soup made with zucchini and yellow squash was first posted in 2008 when I’d just gotten braces on my teeth! I’ve been making it ever since and it’s been very popular on the site! It was last updated with more information in 2026.