This is dish from my childhood.
In June or July, when all vegetables start to mature. Carrots are almost always seeded too closely together. And it is important to thin carrots, they will not grow to maturity unless they have space to do so.
So, you have tiny carrots , first small potatoes are  sweet peas and maybe even first cabbage.. aand this is mean Summer New Vegetables Milk Soup. Easy to do and very delicious.
Of course, you can cook it all year long, but then,. it is not This Soup.