Invasive grass

Vindeezy

Yamadori
Messages
97
Reaction score
110
Location
Hales Corners, WI
USDA Zone
5
Do any of you b-nuts know what I can do to get rid of this invasive grass that took over a bunch of my trees last year.
Thanks in advanced ADF1FE50-B21A-4DBD-9BB6-1C0053757AB7.jpeg
 

Shibui

Imperial Masterpiece
Messages
7,545
Reaction score
15,222
Location
Yackandandah, Australia
USDA Zone
9?
That one spreads from underground stolons and also exploding seed pods. If it has flowered expect new ones to come up in any pots up to 10 feet away. It is a very common nursery weed all round the world now.
You need to get all roots out or it just sprouts again. Seed is viable for several years so stay vigilant to get rid of it.
Glyphosate (Roundup) is effective. I paint it on the leaves of the weed whenever I see it. Glyphostae will kill the entire weed roots and all so saves repeat weeding. Glyphosate is NOT taken up by the roots so will not harm other plants in the pot provided you don't put it on the leaves of your bonsai.
 

Dav4

Drop Branch Murphy
Messages
13,017
Reaction score
29,698
Location
SE MI- Bonsai'd for 12 years both MA and N GA
USDA Zone
6a
Agree with Shibui. I'd also mention I tend to see it thrive in pots with soil that stays too moist, generally speaking. When I have a serious issue with Irish moss in a particular pot, a change out of much of the soil at re-pot (taking into account the health of the tree) is my go to protocol... knock on wood haven't had an issue in years.
 

Forsoothe!

Imperial Masterpiece
Messages
6,878
Reaction score
9,248
Location
Michigan
USDA Zone
6b
I use Round Up alot and in many applications. It leaches sideways. I use it on new clumps of moss, but you have to give it some time to wear off, or else. I would never use it on a potted plant.
 

AlainK

Imperial Masterpiece
Messages
5,394
Reaction score
9,486
Location
Orléans, France, Europe
USDA Zone
9A
Ah glyphosate ! :rolleyes:

I haven't used it for decades, whether in my garden or in my pots. Anyway, it's been outlawed here for a couple of years.

When I repot my trees/bonsai, I just remove them with tweezers. Then, since I don't have hundreds of trees, it's part of the care I give to my plants : I use tweezers, and that's just fine, especially in a free-draining mix.

Oxalis is much more difficult to contain....
 

Adair M

Pinus Envy
Messages
14,402
Reaction score
34,874
Location
NEGeorgia
USDA Zone
7a
Be careful using Roundup! It can most definitely affect a tree in a pot when it’s applied to weeds in the pot. It might not kill the tree, but it can cause deformation of the foliage, and the tree will look “sick”. Curled needles and foliage.

A former apprentice at Boon’s applied Roundup, using a paint brush on just the weeds in the pots of many bonsai. Layer, the trees had curled and deformed leaves. For a while, it was thought there was a mite that infested the garden, but later, it was determined that it was the Roundup. Boon didn’t know the apprentice had applied the Roundup until later. He discovered that the apprentice was doing it without his, Boon’s, knowledge. Once the Roundup “treatments” stopped, the affected trees resumed growing normally.

Two of my trees were affected. They have both fully recovered, but it was scary for a while!
 

Shibui

Imperial Masterpiece
Messages
7,545
Reaction score
15,222
Location
Yackandandah, Australia
USDA Zone
9?
There are many things that can affect trees in pots. Just because roundup was used and then some symptom were observed does not mean that one caused the other.
One year I thought roundup application had caused problems with some banksias here. Turned out they were too root bound and had died from moisture stress. Glyphosate does not travel from one plant to another unless they are grafted in some way. It does not enter plants through roots.
You are welcome to use alternative methods to combat invasive weeds like oxalis and Irish moss. Now that I have it under control I can also mange with pulling them before flowering but the glyphosate is very useful for larger infestations.
 

Brian Van Fleet

Pretty Fly for a Bonsai Guy
Messages
13,961
Reaction score
45,897
Location
B’ham, AL
USDA Zone
8A
That Irish moss is horrible. It’s invasive and really takes over fast. The roots grow fairly deep, and manage to keep the soil wet.

I have never used an herbicide on it, because it just seems counterintuitive to use round up on a bonsai pot. Some have recommended brushing it with vinegar. I remove the moss with tweezers, along with the top 1/2” of soil (soj). It can be a challenge to keep up with on a large collection.
 

Forsoothe!

Imperial Masterpiece
Messages
6,878
Reaction score
9,248
Location
Michigan
USDA Zone
6b
There is no substitute for pulling them at the earliest stage when they are easily wounded. Once you get them down to about zero, the residual old seeds that germinate sort of continuously as do new seeds that arrive with birds, wind, whatever are controllable. If you let one lousy Black Medic, Chickweed, Oxalis, Bittercress or Scottish Moss, et al go to seed, the game is lost for years.

Seeds can remain dormant in soil for 50 or even 100 or more years. It's a survival mechanism that works and varies widely by species. They can be activated by exposure to sunlight when conditions of warmth and moisture are otherwise suitable. That's why plowing at night and seed banks work.

All seeds have tiny little eyeballs that see the light and wake them up. I bet you didn't know that!🥴
 
Top Bottom