tall growing garden weeds

Castor bean is considered an invasive plant in several countries, particularly in the tropics.

A mature plant has hollow robust stems with distinct raised nodes similar to those of bamboo. These can grow up to 13 ft (4 m) each season.

Japanese knotweed, also known as Asian knotweed, Japanese bamboo, or Reynoutria japonica, is a large perennial plant indigenous to Japan, China, and Korea. It was assumedly introduced to the United States and Europe in the 1800s as an ornamental plant. It became trendy due to its bamboo look and because it didn’t have extraordinarily demanding growing requirements.

5. Japanese Knotweed.

There are multiple varieties of sunflowers, some with varying colors for the flower heads and different sizes.

Hopefully, this post will help someone identify a mysterious plant growing in his or her yard one day.

During the first year of life, the plant only produces a rosette of leaves on the ground, and only in its second year, it develops a stalk that can grow up to 2 m (6.5 ft) tall. This ends in a dense inflorescence that can occupy up to half of the stem length. The flowers are yellowish and have very short pedicels.

The leaves of Japanese knotweed are green, oval with a truncated base. The flowers are tiny, white or cream, produced in upright racemes in late summer and early fall.

Despite its pleasant appearance, Ricinus is one of the most poisonous plants in the world. All its parts, especially the beans-like-seeds, contain a deadly naturally occurring toxin called “ricin.” Ricin can be lethal for both humans and animals.

Himalayan balsam (scientific name Impatiens glandulifera) is also commonly known as policeman’s helmet, copper tops, gnome’s hatstand, Ornamental jewelweed, Indian jewelweed, bobby tops, touch-me-not, as well as a few other names.

While a blooming agave is probably the champion when it comes to plants with tall thick stalks, I have omitted from including it in the following list because it’s not usually a plant that simply pops in someone’s yard out of the blue.

6. Wild Lettuce.

Paulownia Tree Saplings by Bazsek / CC BY-SA.

Himalayan Balsam by Philip Halling / CC BY-SA.

This plant can typically grow up to 1.5 m (5 ft) height, forming vast clonal colonies from the expanded root system that send up several vertical shoots throughout the growing season. Its stalks are smooth, green, branched, and mostly lack spikes. The leaves are typically dark green, lobed, present many thorns, and can grow up to 20 cm long and about 3 cm wide, their size gradually decreasing in the upper part of the plant.

The first thing that can help us to identify this plant is its velvety leaves. Because of this quality of his, some commonly refer to mullein as “cowboy toilet paper.”

You can typically recognize this plant by the following particularities.

4. Ricinus.

You can usually identify the Sunflower plant by its stem, large rough heart-shaped leaves, and flowering head. The stalk is thick, has a green color, grows upright, and is usually covered by a thin coat of hair.

Wild lettuce is native to Europe, North Africa, and Asia, but has quickly spread almost everywhere. There are several varieties of wild lettuce. Two of the most popular are Lactuca virosa and Lactuca serriola.

Common sunflower is a large annual herbaceous flowering plant generally grown for its seeds. It is a part of Helianthus, a genus including about 70 species of plants.

In several regions of the US, shrubs from the paulownia genus are considered an invasive species due to their fast-growing nature. Hence, it is not unusual for these trees to expand even five meters in a single year.

Tall weeds with thick stalks are invading your yard or garden and don’t know what kind of plants are those? I made a list of plants with thick and tall stems to help you identify the intruders.

Pokeweed is a perennial weed in the Phytolaccaceae family, native to eastern North America, the Midwest, and the Gulf Coast, as well as to some European and Asian countries.

The Spruce / Jordan Provost.

Like curly dock, orange jewelweed (or “jewel weed”) can be used as a home remedy for poison ivy.   The taxonomic name of orange jewelweed, Impatiens capensis , classifies it as a wild version of the colorful impatiens flowers sold so widely for shady annual beds.

The Spruce / K. Dave.

Japanese Knot Weed (Polygonum cuspidatum)

Polygonum cuspidatum goes by several other common names, including Japanese knotweed and fleece flower. Several other common names include the term, "bamboo," such as "Mexican bamboo." While its autumn flower does, indeed, look fleecy, "fleece flower" is just too dainty a name for so tenacious a weed!

It's not for nothing that this plant is named, "giant ragweed." It can grow up to 15 feet tall, with thick roots and branches. Like its ragweed cousin (and unlike goldenrod), giant ragweed produces a great deal of pollen which causes serious allergies.  

Wild madder is, like sweet woodruff, in the Galium genus. Wild madder is also called "bedstraw." Apparently, people did actually once use this weed as a bedding material. Sweet woodruff is a creeping, mat-forming perennial that pretty clusters of white star-shaped flowers in spring and has very fragrant, lance-shaped dark-green leaves.

While many consider clover a “weed,” there’s really nothing wrong with having a little clover mixed into your lawn. The Irish consider various tripartite clover leaves (such as the one in the photo here) to be “shamrocks.” The tradition behind the shamrock is quite distinct from that behind four-leaf clovers.

Common ragweed may be an important weed for you to identify, even if you don't care about keeping your yard weed-free for aesthetic reasons. If you're an allergy sufferer, you should be aware that common ragweed is a major source of hay fever.  

The Spruce / Adrienne Legault.

Orange Jewelweed (Impatiens capensis)

Curly dock (also called "curled dock" or "yellow dock") is more than just distinctive, it's also useful: curly dock serves as a home remedy to treat stinging nettle burns–though it can be toxic to consume.   You'll be able to identify curly dock by its greenish blossoms that cluster long thin flower stocks. After the flowers have dried and turned brown, they remain in place, making the plant easy to recognize. The flowers start out a much less distinctive light-greenish or reddish color. Blooming occurs in clusters in the form of multiple, long, skinny flower stalks at the top of the plant.

The Spruce / K. Dave.

The Spruce / Evgeniya Vlasova.

The Spruce / Lindsay Talley.

Wild Madder (Galium mollugo)

A rather innocuous plant, common plantain can simply be mowed whenever you mow the lawn. Its relative, Plantago lanceolata is a similar weed, but with narrow leaves. Now a ubiquitous lawn weed in North America, broadleaf or "common" plantain was brought to the New World by colonists from Europe for its medicinal uses. Common plantain has many medicinal uses. Mashed, it can be used as a poultice for bee stings; the leaves can also be dried and made into a tea to treat diarrhea.  

The flowers of stinging nettle plants are inconspicuous. You'll pay plenty of attention to its barbs, however, if you're unfortunate enough to brush against stinging nettle! The discomfort these weeds can cause seems incongruous with the fact that stinging nettle is edible. But the young leaves of stinging nettle are, indeed, cooked and eaten by wild foods enthusiasts. Just be sure to pick at the right time and prepare properly to ensure safe consumption.

The Spruce / Candace Madonna.

Once you've identified nuisance plants, you can more readily access information on eradication. In some cases, however, finding out more about the plants in question may persuade you to show more tolerance toward them. There are even some edible weeds. Some are worth your time to remove while others don't cause much harm (and may even have beneficial aspects).

The Spruce / David Beaulieu.

Weeds like other plants have different types of roots:

Irena on May 18, 2020:

Eugene Brennan (author) from Ireland on July 09, 2020:

7. Lesser Celandine.

Hi Sarah, sounds like catsear or flatweed if it resembles a dandelion.

Alexander, Stephen (June 2020) Illustrated Guide to Horticultural Weeds Teagasc Horticultural Development Department, Ireland.

Lisa on May 22, 2020:

O'Neill-East on June 01, 2020:

"Weed" isn't a botanical term like conifer or deciduous or perennial , words that mean something specific. "Weed" is a subjective term but generally can be considered as an unwanted plant in the wrong place. Weeds are usually wildflowers or plants with insignificant blooms or ugly foliage, in contrast to the prettier wild flowers or cultivated and showy flowers we grow in our gardens. (It's interesting to note that many cultivated flowers self-seed or propagate themselves in other ways so readily in our flower beds, that they can eventually become a nuisance and earn the title "weed" themselves.)

Eugene Brennan (author) from Ireland on June 01, 2020:

Flowers of convolus arvensis or common bindweed.

References.

If the weeds have tap roots, pulling normally just tears off the top growth and they grow again. Weeds with a fibrous root can normally be pulled up a lot easier.

Here is a guide to the most common garden weeds.

Dandelion seed head. Parachute-like seeds are dispersed by wind.

I have 2 particular weeds that are not pictured. It there a ways to send them to you? also, does pulling them out promote growth?

I'm only familiar with the weeds in the UK/Ireland. There are also several apps for weed ID in different countries. The BASF Weed ID app covers 140 weeds in the UK. For the US, two examples are ID Weeds and [email protected]

13. Cleavers (Goosegrass, Stickyweed, Robin-Run-the-Hedge, Sticky-Willy)

Eugene Brennan (author) from Ireland on May 27, 2020:

A weed is an unwanted plant in the wrong place.

Many weeds can be killed naturally either by hoeing, mulching, covering or burning with a gas or kerosene blowtorch. Annual weeds with shallow roots can usually be pulled by hand. You can also use vinegar to burn the foliage on annual weeds and young seedlings. Weed control fabric is another option to stop them rooting down through stone paths.

I work for a charity and we have weeds growing on our church bell tower. We would like to identify them so we can find out the best way to kill them, as it is costly to keep doing this. Can i have an email where i can send photos too and get some advise please ?

Burr from herb Bennet.

Unfortunately there is no way of sending us photos, however if you are on Twitter, you can tweet me at @EugenesDIYDen.