Glass in garden soil is very common and there are different reasons for this occurrence. It will not affect plant growth but it can cause injury if you are not careful.
Glass can be present in garden soil as a result of improper disposal. Broken glass will not affect plant roots because it is chemically inert. However, it can pose a hazard to gardeners when maintaining the soil. Glass can be removed by hand with the proper PPE when exposed at the surface.
In this article, I am going to outline the different scenarios in which glass can end up in garden soil, its effect on plants, and what you can do to completely remove it from garden soil and from lawns.
How Does Glass in Soil Affect Plant Growth?
Glass has no effect on soil and plant growth. Glass is essentially sand, (99% silica) which has been melted to down. With glass in the soil, the plant roots will tend to grow around the glass in their search for nutrients.
Glass can be present within the soil as sharp broken pieces or even an entire jar within the soil and it still will not affect the growth of the plants.
Broken glass will not cause harm to the roots if:
- The glass itself, is not moving
- The root is not moving quickly against its sharp edges.
Glass is actually chemically inert in the soil as it does not add nor take away any nutrients from the soil.
Inert – the term inert is used to describe something that is not chemically active
Fact – Silicon/Silica is a mineral present on earth in abundance. The element makes up about 28% of mineral soil by weight.
Therefore with this amount of silica present on most soil, having glass in the soil will not affect plants.
How does Glass End up in Garden soil
Broken Glass was used to Eradicate pests
A common practice for some gardeners is laying sharp materials around their garden in an attempt to deter snails and other crawling pests from the garden.
The concept stems from the fact that the snails crawl to get to where they are going and by having these sharp barriers in their way would deter them from venturing close to vegetable plants.
Over time the glass then sinks into the soil if it’s forgotten or it is just tilled into the soil when preparing for the next batch of crops.
Buried from previous house owners
The practices of people are sometimes strange and maybe it was some type of hobby of using glass bottles as shooting targets.
Sometimes it may be difficult to dispose of large amounts of broken glass or there is just not the facility to do so.
The easy option then would have been to bury the broken glass within the soil.
Additionally, Victorian and older houses often used the gardens as rubbish dumps. Since at the time there were no garbage disposal systems in place to handle the waste produced by households in the era.
By burying the glass people would have been assured that the shards would have not caused harm for those walking in the area as the soil would act as a protective barrier.
Unfortunately, the area could well be another person’s garden in the future which is a very likely cause of glass in the garden soil.
The land was previously used as a garbage fill
This is often the case with reclaimed land. If there was some type of manufacturing facility or grocery or even a small business, burying broken glass and other garbage items could have been a quick and easy way of disposing of unwanted items.
Without knowing the history of the land on which the property was built, there may be some probability that the land was used for garbage disposal at some point in time.
Bell Jars were used to protect crops
Bell jars are often used to create a miniature greenhouse effect around a plant, they can allow earlier planting and often speed up seed germination by keeping the top layer of soil warmer.
For whatever reason, if there is an accident the broken glass would inevitably end up in the garden soil.
Over time the glass would have been buried further into the soil as more and more as dead plants and dirt cover the surface.
What are the Dangers of Having Glass in Soil?
The structure of glass is such that when it breaks it separates creating razor-sharp edges in most cases.
Over time, with the reasons discussed above these glass shards get embedded within the soil. They don’t cause harm to plants but they do to the people handling the soil during routine garden maintenance.
The danger of having glass in the soil is that it creates a potential hazard to you, the gardener. When transplanting or moving soil around by hand there is the risk that you may get cut by pieces of glass within the soil.
Additionally, glass is a very brittle material and when struck can propel splinters into the air. This can happen when digging into the soil with garden forks or pickaxes.
This is why I do recommend that if you know that there is glass in your garden’s soil, then you should take the necessary precautions to prevent any possible injury.
Best Safety Glove and Glasses for Handling Glass in Soil
The best safety glove and eye protection for handling broken glass should cover you in all hazardous scenarios while at the same time being both comfortable and durable.
After handing glass-filled soil for some time and sustaining multiple minor cuts, I decided to look into getting a pair of safety gloves to save myself the pain of sterilizing the wound.
The problem is that it was hard finding a glove that would both protect my hands and be comfortable to work with without feeling restricted.
The Fortem Cut Resistant Gloves from amazon fixed that problem easily.
Now I had to take into account the glass projectiles.
The smallest piece of glass once it enters the eye can cause massive damage and I was not ready to risk that after all, you cannot replace an eye so I got the Pyramex Proximity Safety Glasses which is surprisingly cost-effective and durable.
You can find it by clicking here!
It was both comfortable and provided UV protection while protecting my eyes.
Problem solved! I was able to safely handle and remove the unwanted glass from my garden soil.
How to Remove Glass from Soil
In order to remove glass from the soil, it has to be visible.
Here is the method I use to reveal the glass for removal.
- Clear the area of grass by hand.
Note: Using machinery like a string trimmer can send shards of glass flying into the air.
- Use a tiller or a rake and fluff the top layer of the soil. You will feel the glass knocking against the rake when you do.
- Using a hose or watering can, sprinkle water over the fluffed soil.
- The lighter soil will wash away revealing the glass on top.
- Now all that is left is to pick up the broken glass by hand or with a grabber tool.
When removing glass from soil you should wear cut-resistant gloves to prevent injury.
In the event that you do not have gloves, an easy alternative is to use a Grabber tool. I got mine on amazon and it’s amazingly cost-effective and durable.
The best alternative to removing glass from soil and avoiding the hard work is to build a raised bed garden.
Raised bed garden can be built on top of old soil or even hard surfaces totally illuminating the potential hazards present in the ground beneath.
The raised bed is built 2 to 3 feet above the ground after which it is lined with waterproof material with proper drainage in place. The first layer is filled with tree bark and leaves which are then covered to the top with new nutrient-rich soil.
What are the Dangers of Having Glass in Grass?
Most of the walking areas in the garden and in our backyards are covered with grass.
With day-to-day activities, family get-togethers and playtime accidents can happen, and one such accident is when a bottle or drinking glass has been broken and falls onto the grass.
The broken glass can easily get tucked away between the blades of grass and if not properly removed can be a casualty waiting to happen.
I know this all too well because as a child I got a nasty cut on my right foot which required six stitches after sliding on wet lawn grass from planting soccer, not knowing that there was broken glass there.
Similarly broken glass, in the grass in our backyards and in the garden also poses a risk to pets and animals alike.
Pets can easily get cut while running through grass which can lead to excruciating pain and worms if the wound is not attended to.
With these unfortunate scenarios in mind, it prompts us to look into ways to effectively remove the glass from grass as soon as possible, which is what I did.
How to remove broken glass from Grass
Removing broken glass from grass in a timely manner will save unwanted accidents which may require medical attention.
Here I outline the steps to effectively remove the glass from grass from my years of experience.
Personal protective equipment should be worn when removing glass from grass to prevent injury.
Here are the safety glove and glasses I use:
- Playdoh or sticky substance
- Wrapping paper
- Barrier/ marker (to prevent or alert anyone around of the hazardous area)
- The first step is to properly mark or barricade the area so that no one ventures into the danger zone.
- Remove the larger pieces first, placing it onto the wrapping paper.
Note: the wrapping paper is for safe disposal when placed into garbage. The glass should ideally be placed in a recycle bin.
- Use a vacuum cleaner to remove the smaller pieces of glass
- Now after there are no more visible pieces, use a large piece of playdoh or sticky goo and gently rub it onto the and between the grass.
Miniature broken glass splinters can easily be removed using a gooey car detailer or Cleaning Gel. It picks up the smallest pieces of glass splinters
You can find it by clicking here!
If you would like to take it a step further the grass where the glass has fallen could be completely removed by digging into the soil about 2 inches and removing the top layer.
You can use Michigan Peat Garden Magic TopSoil to fill the void where new grass can then grow on.
Is Glass Good for soil?
Glass does not add nor take away anything chemically from the soil. Glass physically takes up space within the soil but does not affect root development. Roots cannot get cut or lacerations from broken glass as there is no moving contact with the glass.
Although glass does not affect the chemical composition of the soil it does pose a physical hazard to those preparing the garden for planting or any gardening activities.
Glass should not be in soil and from a safety standpoint it is not good for soil.
Can Glass be Composted?
Glass cannot be composted and should not be placed in compost. Even if the glass is broken into very small pieces, the finished compost will still contain the glass material which was initially added and it will be very difficult to remove.
Glass does not chemically contaminate compost as it does not break down easily. Even if it does break down, it’s made of 99% silica which is one of the most abundant elements in the soil.
Can Glass be used Instead of Stones?
Since glass is chemically inert it can be used in place of stones when lining the bottom of plant pots. The only concern there is if the glass being used is sharp.
Tumbled glass is a good alternative to stones as the sharp edges from the broken glass have been dulled or rounded out. As a result tumbled glass will not cause cuts or bruises when being handled.
Apart from tumbled glass, marbles are also a product of glass that is relatively cheap and widely available. Marbles when used to line the bottom of a planter will help with soil drainage.
Using Glass as Mulch in the Garden
Glass can be used as mulch in the garden in the form of tumbled glass. Using tumbled glass mulch made from used glass bottles, old windows, and other glass products keeps glass out of landfills.
Glass when used as mulch will last for a long time and will allow water to flow in between their spaces preventing them from being washed away whenever it rains.
However, a downside of using glass mulch is its weight. When packed together, the weight of the glass mulch can press down the soil causing it to compact over time. This can lead to improper soil drainage and aeration which will affect a plant’s development.
Using Glass Containers for Planters
Glass containers can be used for transplanting plants especially succulents. The only downside is that if the jar is left in full sunlight the soil may ten to start growing moss from the side that is exposed to the full light while the other sides remain normal without moss.
Rotating the jar can help eliminate this effect of light and moss growth and can have other benefits such as more symmetrical plant growth which aids in the aesthetics of the plant.
If the glass planter is unavoidably exposed to a high amount of light you can always opt for coating the glass with some type of coatings like spray paint or papering, but this takes away from the beauty that comes with planting in a glass planter.
Additionally, the glass jar will give you insight when the succulent needs replanting as you would see the roots showing to the sides and at the bottom of the planter.