How to Grow Portobello Mushrooms at Home

By Helen Reed Posted on 6/17/19

Growing up, the only thing I know about mushrooms was that they are among the few non-green plants thanks to third grade science. Back then, the idea of growing mushrooms for consumption had not clicked in most people’s minds, especially given the fact that over 80% of the mushrooms species are either poisonous or tasteless. However, in the 21st century, we have mushroom dishes that are served even in 5 stars hotels globally. In particular, Portobello mushroom are quote popular, with a fresh meaty and intense flavor. But, how do you grow these mushrooms. Well, you have come to the right place since we will walk you through a step by step guide on how to grow Portobello mushrooms.

What are Portobello mushrooms?

Before we can proceed any further, let’s not assume that anyone reading this post know what Portobello mushrooms are, do you?

Portobello mushrooms belong to the Agricus Bisporos family and were natively grown in Europe and North America. They are basically an immature form of buttom mushrooms. Back then, the mushrooms grew in the wild, but in 1908 the first effort to grow Portobello mushrooms was recorded. One of the main reasons why you should learn how to grow Portobello mushrooms is the fact that they can be grilled, baked, boiled, sautéed or fried, making them a perfect ingredient for just any meal.

General characteristics of Portobello mushrooms

Just like any other mushroom, Portobello are non-green, meaning that they lack chlorophyll. The lack of chlorophyll means that they do not make their own food and therefore there is less need for sunlight.

Portobello mushrooms form large brown caps and have an intense meaty flavor. They are harvested when the caps are 4-6cm in diameter. They grow from spores and on dead decaying organic matter.

Why you should learn how to grow Portobello mushrooms

One would wonder, why should you go through all the hustle of growing the mushrooms when you can buy them online or on the grocery shop? Well here are the reasons why you should grow the mushrooms yourself.

  • It is cheap

If you are still green on growing and including mushrooms in your diet, don’t be astonished if you find out that the price tag is 2 or 3 times more expensive than you had anticipated. Portobello mushrooms in grocery shops or online stores are very expensive. By growing the mushrooms yourself you will be cutting on some expenses.

  • It is fun

It is for a fact that some people have weird hobbies. Growing mushrooms is one of those hobbies. It is fun to grow mushrooms since they mature quickly.

  • Go organic

When you grow the mushrooms yourself, you are in control of what to use. Unfortunately, you might be disappointed to learn that the mushrooms written “organic” at the supermarket were grown with chemical fertilizers that can be harmful to your health.

Nutrition value of Portobello mushrooms

Portobello mushrooms are not only delicious but also pack nutrients. It is these nutrients that have made the mushrooms quite famous. After trying Portobello mushrooms, there is a high chance they are going to be one of your favorite foods moving forward.

  • Portobello are low on carbs, fatty acids and cholesterol. This explains why it is marked as safe to consume by people with diabetes. Studies have actually shown that eating mushrooms actually helps in lowering blood sugar levels.
  • Fiber is essential to our bodies since it helps in ensuring smooth bowel movements and Portobellos make such a good source of fiber.
  • High in vitamin D, vitamin B and potassium. Here is something that will shock you. Portobello mushrooms have more calcium than a banana.

Factors you can never ignore when growing Portobello mushrooms

Mushrooms are not all that challenging to grow however; there is a checklist of things that you should get right if your mushrooms are to reach maturity.

  • Watering

Portobello are very sensitive when it comes to water in the sense that they require much of it. You are required to water the mushrooms once every two days. Don’t soak them up, as much as they require a lot of water, the growing medium should only be damp, not soaked. Never allow the growth medium to dry up.

  • Light

Over 95% of plants are green and rely on chlorophyll that uses the sun to make food. Mushrooms belong to the minority 5%. The sun has no positive effect on the mushrooms in fact, if you are to expose mushrooms to direct sunlight they will dry out. When forming heads you can provide the mushrooms with dim light to speed up the process.

  • Temperatures

The fact that mushrooms don’t do well on direct sunlight should tell you that they won’t do well on high temperatures. Portobello mushrooms should be grown in temperatures below 80 degrees F. Ideally this should be 60-75 degrees F.

  • Humidity

If you guessed that high humidity is deal for growing Portobello mushrooms you were right. They require high humidity levels of up to 80%.

  • Harvesting

Mushrooms are not harvested by tractors. Well just kidding, who would expect mushrooms to be harvested by tractors anyway? Mature mushrooms are handpicked.

Step by step guide on how to grow mushrooms

There are two ways in which you can grow mushrooms by using spores or a handy kit. A handy kit is perfect for beginner and contains everything you need to start growing the mushrooms. Growing mushrooms with spores on the other hand is rather challenging but fun. Both ways will achieve the same results don’t shy off from any.

Step by step guide

  1. Select an area

Start off by selecting an area where you would like to grow the mushrooms. This can either be in the grow tents or outdoors, but you should always have in mind that this should be away from direct sunlight. The location is only a issue when you opt to go outdoors. As long as you find an area where the mushrooms won’t be exposed to direct sunlight you are good to go.

  1. Prepare compost

This step is only applicable if you are growing mushrooms from spores. If you decide to purchase a handy kit there is no need to make compost. According to, the main reason why compost is chosen is due to the fact that mushrooms grow on dead decaying organic matter and compost is not only dead and decaying but also rich on nutrients.

  1. Prepare a bed

Again, you only prepare a bed if you’re growing with spores. The ideal measurements for the growth bed should be 4*4fts and 8 inches. This measurement isn’t fixed but just an ideal measurement. Once the bed is ready, put in the compost mix you prepared.

  1. Mix the compose with the spores

If you’re using a handy kit, all you have to do is water the medium and place it in the designated area. For spores, you have to mix them with the compost then water the mixture. It is recommended that the designated area is dark and regular watering is ideally once every two days.

  • Ready to harvest

Portobello mushrooms are ready for harvest when the caps turn brown and measure 4-6 centimeters on diameter.


There you have it, that’s how to grow Portobello mushrooms at home. Show some love by sharing this article with a friend or two. If by any chance you feel that we left something out, feel free to share it in the comment section below.