Corn gluten meal can also be used to control weeds, but is it worth it?

I came across a foreign article about a method of using corn gluten meal to control weeds, and I found it hard to believe - isn't that stuff used to feed pigs?

(You can see it has an NPK content of 8-0-4, so it's also a fertilizer.)

Actually, if gardeners go out and buy corn gluten meal, most of what they get will be animal feed; only the kind sold at garden centers works.

In modern gardening, the main ingredient in weed killers in many regions is corn gluten meal. You can check the packaging when you buy a general weed killer.

In China's "Journal of Plant Protection", I also came across "The Pre-emergence Herbicidal Activity Mechanism of Corn Gluten Meal". Corn gluten meal has a particularly good control effect on 8 major weeds. However, unlike older weed killers, you can't use it at any time. Using corn gluten meal comes with a certain timing restriction and a very specific method of application - it is only effective when used at the time the seed embryo is germinating.

In gardening, we should make more use of organic methods for weed control, and keep developing healthy, green gardening. Harmful pesticides or methods from the past should stay banned (especially those that cause permanent damage to the soil), and some that are very effective still get questioned (the dangers of pesticides).

Only when new healthy products are born can they keep up with the times. Gardening books published ten years ago may need to be phased out, and articles about gardening constantly need updating.

Corn gluten meal is a very new product. It was only a little over twenty years ago that a professor in the United States discovered that this stuff actually has a very good effect in preventing weed seeds from germinating.

This stuff is a corn by-product. In the past it was used to feed pigs, and it even comes in good and bad grades. It also contains a very high level of nitrogen fertilizer.

In foreign garden centers, I saw that many places sell large bags of weed killer containing corn gluten meal. They're labeled "100% corn gluten meal", or sold under other names and contain around 90% corn gluten meal. Whatever the name, the key phrase is "inhibits seed germination", meaning it stops weed seeds from sprouting.

On the packaging of these corn products, it's emphasized that they are most effective against dandelions and crabgrass, and also useful against other common weeds.

There are two time windows when application works best. The reason is that the main germination periods of these weeds fall into two key periods, so using it then gets twice the result with half the effort.

(Forsythia flowers)

The early spring period in particular is the main time for weed seeds to sprout. To judge the timing accurately, you can use the reference of when forsythia blooms until two weeks before lilacs bloom. If you don't have these two flowers near your home, then ask at a flower shop, because the timing differs by region. (Gardeners in the south can use the two weeks when flowering dogwood blooms as a reference.)

The other period is late August to early September in autumn.

(Lilac flowers)

At the time of application, the lawn should already be wet, and it should rain within two days. If it doesn't rain, you'll need to water it yourself. In short, there needs to be water after application for the corn gluten meal to enter the soil. But at the same time, don't use too much water, or the effectiveness of the corn gluten meal will be diluted.

(Dandelion)

Corn gluten meal appeared in order to replace the weed killers that came under heavy attack in the past. It is 100% natural, so it is non-toxic and harmless to people and animals.

(The type above has a particularly high nitrogen content, and is sold as a nitrogen fertilizer.)

Its effect is that as soon as a grass seed opens up to germinate, it dries the seed out and takes away its ability to germinate. So if you've just sown grass seed, don't use it. (After using corn gluten meal, wait at least six weeks before sowing grass seed, preferably two months.)

(Crabgrass)

The corn products currently sold come in powder form and in granular form. Apply evenly, and it's best to use a spreader for grass seed or fertilizer. The dosage is indicated on the packaging. It is also fairly high in nitrogen, so don't fertilize the lawn again after applying it.

Note: When buying corn gluten meal, you must buy it at a garden center. If you buy it at a feed store, although it's several times cheaper, that kind is for feeding pigs and has no effect on stopping seed germination. I never imagined corn meal could be used to control weeds - do you think it's worth it?

The time window in which corn gluten meal can be used is very short, and the amount needed is not small either, so gardeners can just take a look at it. Generally, it's still better to use common weed killers, which are much more effective. Many pesticides have been banned because their residues cause permanent damage to the soil, so these organic weed-control products that can also add fertilizer are still worth researching.