Why plant factories? The reason why the cultivated items are only leafy vegetables

Hello everyone! I’m Shohei.

Plant factories tend to grow leafy vegetables such as lettuce, spinach, and Japanese mustard spinach.

I’ve visited many factories, and almost all of them cultivate lettuce.

Many people must be wondering.

Actually, this is because plant factories have certain characteristics.
Because of these characteristics, the reality is that only leafy vegetables remain as options.

In this article, I will explain in detail why leafy vegetables are suitable for plant factories from the aspects of “growth characteristics” and “economic efficiency.”

By the way, lettuce is the most common among leafy vegetables, but why?
I’ve also written about that below. Please take a look.

Characteristics of Plant Factories

First, let’s organize the characteristics of plant factories.

A plant factory is a facility that can artificially control environmental conditions such as temperature, humidity, light, and CO2 concentration.
Thanks to this, year-round and planned production of crops is possible.

Unlike open-field cultivation or other greenhouse horticulture, it is characterized by stable production with little influence from the external environment.

Why Leafy Vegetables are Suitable for Plant Factories

So, why are plant factories suitable for leafy vegetables?

The conclusion is,
It’s because of the growth characteristics of leafy vegetables and the high proportion of edible parts.

Let me explain in more detail.

Leafy vegetables are characterized by leaves being the main edible part, and the proportion of leaves in the entire plant is high.
In other words, almost all of the cultivated crops (except the roots) are basically edible.

Also, because the leaves grow quickly, it takes only a short period of time, about 30 to 40 days from sowing to harvesting.

This characteristic makes it suitable for year-round and multi-stage cultivation in plant factories.

You Can’t Waste the Costs

This is because plant factories are extremely costly.
Especially the electricity bill for the LEDs used to grow crops. This is terrible.

Light is absolutely necessary to make the leaves grow large.
But light also costs money in terms of electricity bills.

This is the point.

For example, if you grow vegetables like tomatoes that discard the leaves and obtain the fruit, you cannot recover the cost spent on the leaves.

Therefore, plant factories can only grow vegetables that can be cultivated in large quantities (of edible parts) with high turnover.
That’s what it comes down to.

Vegetables with slow growth or a large amount of discarded parts will quickly run into the red.

By the way, in addition to this article,
I’ve written about “this item is a little difficult for plant factories…”

For example, wheat, soybeans, root vegetables, rice, etc…

The above-mentioned items are difficult.

But there may be some misunderstanding.

As I wrote in these articles, grains and root vegetables cannot be cultivated in plant factories…
Rather, it feels like “there is no merit in cultivating them in plant factories.” If you really wanted to, you could technically cultivate them.

Three Conditions for Vegetables Perfect for Plant Factories

So, what crops are suitable for plant factories?
The conditions are as follows:

Leafy vegetables meet these conditions.

For example, in the case of lettuce, it is short, taking about 30 to 40 days from sowing to harvesting, and can be produced throughout the year by controlling the environment inside the facility. Moreover, everything except the roots can be eaten.

Lettuce… what a convenient vegetable for plant factories.

And some leafy vegetables have high levels of nutrients, vitamins, and minerals.
Furthermore, by controlling the cultivation environment, there is room to change the nutritional value. This is also suitable for plant factories.

In addition to leafy vegetables, some fruits are also suitable for plant factories.

Well, not all fruits apply, though.
I’ve written about fruits in the article below.

Leafy Vegetables are Advantageous, but On-Site Skills are Essential

After all, the challenge of plant factories is the high initial investment and operating costs.

The initial investment for construction costs, air conditioning equipment, lighting equipment, etc. is large, and the running costs such as electricity bills are also high.

How high is it?
There are so many factories that go into the red due to high costs and go bankrupt or withdraw from the business.

Having been in the plant factory industry for a long time, I’ve seen many such companies.
It’s sad.

Leafy Vegetables Have Many Advantages, But…

The theme of this article was “Leafy vegetables are advantageous for plant factories.”

However, there are cases where even if you grow leafy vegetables, you will still end up in the red. That’s how difficult it is.

There are also factories that are making solid profits.
In my experience, those plant factories have high-level on-site staff.

In other words, the truth is that understanding the correct know-how is important for profitability.

However, there are surprisingly few ways to learn the correct know-how.

If you want to improve your on-site skills, please refer to our site.
The following content will be helpful in increasing the profitability of plant factories.

Summarizing the Content

The three reasons why leafy vegetables are often cultivated in plant factories are:

In plant factories, where costs are high, leafy vegetables with these characteristics are the best option.

Rather, it can be said that there is no point in cultivating other vegetables.

Leafy vegetables’ growth characteristics and distribution of photosynthetic products match the characteristics of the artificial environment of plant factories, which is why leafy vegetables are cultivated in many plant factories.

Recently, wasabi has also been attracting attention as a crop that makes full use of such artificial environments.

Please see the article below for an explanation of wasabi.

In order to increase the productivity and cost recovery rate of plant factories, it is essential to cultivate crops with short harvesting periods and minimal loss, such as leafy vegetables, and to develop technologies such as efficient environmental control and automation.

What are the weaknesses of plant factories?

The biggest weakness of plant factories is probably the high initial investment and operating costs.
The initial investment for facility construction, air conditioning equipment, lighting equipment, etc. is large, and the running costs such as electricity bills are also high.
Also, there’s the problem of not having people who are skilled at using those facilities and knowledgeable about vegetables.
In other words, securing specialized personnel is also an issue.

What are the characteristics of plant factory lettuce?

A major characteristic of lettuce grown in plant factories is that a stable quality and supply volume can be ensured throughout the year.
In addition, it is basically pesticide-free, and its high level of safety is also a characteristic.
The catchphrase “can be eaten without washing” was often used. It’s not used much these days, though.

What vegetables are grown in plant factories?

Leafy vegetables such as lettuce, spinach, and Japanese mustard spinach are mainly cultivated in plant factories.
In addition, various items such as baby leaves, salad greens, arugula, and herbs can be cultivated. In recent years, fruit vegetables such as strawberries and tomatoes have also been trialed for cultivation in plant factories.