Skip to Content

How tall can weeds grow?

Weeds are unwanted plants that grow on lawns, flowerbeds, farms, sidewalks, and anywhere with favorable conditions.

The problem is most weed species reproduce rapidly. They will likely take over your farm faster than expected. Some of them can stay dormant for years, making it very hard for you to control them.

So, how tall can weeds grow?

Contrary to popular opinions, weeds are not always small plants that pop up in between your plants. Instead, some are fully grown trees that can measure up to 60 feet.

No matter the size of the weed, it is imperative to destroy it as soon as you can. If you let the weed trees continue thriving, they will suck up all the nutrients from the soil resulting in the death of other nearby trees.

Common weeds that grow tall

It is challenging to identify harmful weed trees as they are not very common. Note that not all weed trees are harmful. It depends on where it has grown and your plans with the land.

Below are a few of the most common ones;

1. Pokeweed

Image: Olya Solodenko

Pokeweed is a perennial weed primarily found in Asia, Midwest, Gulf Coast, North America, and Europe. It has a pervasive taproot system that makes it extremely hard to get rid of.

READ ALSO:  How to remove dead weeds from gravel or rock landscape

However, if you left to its own devices, it can quickly grow as tall as 10 feet.

Pokeweed is extremely dangerous to humans, pets, and most farm animals because it carries a poisonous toxin in its stalk and fruits.

However, some small animals are immune to the toxin and can therefore feed on poisonous fruits with no repercussions.

You can quickly identify Pokeweed thanks to its thick reddish stem that turns purple when mature and its tiny white flowers.

Also, its fruits resemble berries that are green when unripe and turn purple when ripe.

2. Ricin/castor bean plant

Castor bean (Ricinus communis)
Image: Boggs

Ricin is a native plant in Africa and Asia but has successfully spread worldwide. If the climate is suitable, this plant can grow up to 12 feet tall.

As the name suggests, Ricin is the plant that produces castor oil that is widely used for its medicinal properties.

Despite all its good qualities, Ricin is one of the most poisonous weeds to humans and the soil. Its seeds resemble beans and contain a poisonous substance known as Risin.

When Ricin comes into contact with the soil, it seeps in and destroys the roots of all the neighboring plants causing them to die.

Thankfully, you can easily recognize this plant as its large leaves resemble an open human palm. Its stalk is very thick and has a reddish color.

READ ALSO:  Do you have to pull weeds after spraying?

3. Japanese Knotweed

Japanese Knotweed

Japanese Knotweed is a herbaceous weed from the Polygonaceae family. It was first discovered in Asia but recently found in North America and parts of Europe.

It is difficult to identify this plant when it is young as it resembles thousands of others, but when it is mature, you can tell it apart because of its hollow stems and raised nodes.

The Japanese Knotweed is very invasive. It has been listed on the noxious weed list in many countries.

It tends to sprout in dense bushes and then multiply rapidly until it crowds out the other native plans, killing them.

If you find it sprouting in your yard, you can either use chemicals or organic methods to get rid of it it.

4. Black locust

Black Locust

Black locust weed is very aesthetically pleasing -it has white flowers, orange bark, and narrow seedlings with lengthy leaves.

It belongs to the legume family; hence its seeds can be mistaken to be edible. However, they are not.

Black locust reproduces by spores which can be easily dispersed by the wind. This is why they can quickly colonize your land, making the soil inhabitable for native plants.

Therefore, it is in your best interest to destroy this plant as soon as it sprouts. If the environment is right, Black locust can grow up to 50 feet allowing you to mistake it for a tree.

READ ALSO:  How to sharpen lawn edger blades

How to deal with tall weeds

Ideally, it would be best to get rid of weeds when they are still seedlings, as it will be straightforward that way.

However, if by any chance you find a weed that has grown to the size of a tree, then here are a few ways to go about destroying it;

  • Paint: Grab a power saw and cut down the canopy, then paint the place where you have cut to prevent regrowth.
  • You can tow it using a truck.
  • Chemicals: There are thousands of store-bought chemicals that are designed to kill weed trees.

You are better off dealing with weeds as soon as possible to prevent them from taking over your lawn. This is especially true for weeds that grow tall.

But first, you need to identify the weed you are dealing with to know which method will work best.

Read More