Do you have a problem with green algae growing in your garden? High levels of humidity and moisture in the area cause a green covering to form on top of the soil. It’s also OK for your plants to have algae on them. Manually picking them out of your plant or soil is the simplest way to get rid of them.
But algae don’t have any of these characteristics: roots, leaves, or stems They thrive in warm, moist, and damp environments, which is why seed starting mix is a typical place for them to flourish. When your plants are covered in algae, you may be overwatering them. Overwatered plants, especially in hot and humid weather, are more likely to be infested by algae.
How Does Algae Affect Your Plants?
Your plants won’t be affected directly by algae because it’s not a parasite or illness. However, having algae in your soil has its drawbacks.
Algae can harm your plants in a variety of ways.
Moisture retention by algae in your soil can contribute to the development of mold and other plant problems.
For one thing, algae can compete with each other for water and nutrients. For a lengthy period of time, they develop a hard crust on the soil, making it harder for water to reach your plant’s roots.
How to Eliminate Algae in Your Soil?
Algae in the soil isn’t harmful to plants, although many gardeners prefer to remove it. For aesthetic reasons, you may also want to remove algae. Regardless matter the cause, here are a few methods for getting rid of algae:
Tip #1: Do not overwater
Overwatering can promote the growth of algae and other problems since algae prefer moist and wet environments. Algae can be prevented by carefully watering your plants.
Tip #2: Cultivating the soil
By cultivating your soil, you may not only encourage the growth of your plants but also get rid of any algae that has accumulated around them over time. It is impossible for algae to grow and germinate in an area that is kept moist by cultivating the soil.
Tip #3: Cover from sunlight
When sunlight and aqueous conditions are in balance, algae thrive. Algae development can be minimized and eventually eliminated by using plants and locations that provide shade. Sunlight is the primary source of energy for photosynthesis in algae, thus without it, they won’t be able to grow.
Tip #4: Use of bathroom cleaner
Other gardeners and growers claim that bathroom cleanser is an efficient way to get rid of different kinds of algae in your pots, containers, and backyard garden.. Using bathroom cleanser, which has chemicals that may successfully remove dirt, you can progressively eliminate the algae in your garden by applying and spraying it in areas where it is dominating.
Tip #5: Sprinkle cinnamon on the algae
Algae can be thwarted by cinnamon’s natural repelling properties, keeping it from spreading and taking the nutrients your plant needs.
Tip #6: Take a damp paper towel
and wipe the algae-infested dirt with a broom. This will remove the excessive algae that has accumulated in the surrounding area by cutting and pulling (flowerpots, containers, gardens).
Tip #7: Avoid using perlite, vermiculite, and peat moss
Because of their high water absorption, these materials will be damp for the most of the time. Algae thrive in this type of environment.
Garden Soil Turning Green? (Plus 6 Tips You Can Use To Stop It!)
You’re not the only one who has noticed that the soil or seed starting mix in your garden or greenhouse is becoming green. This is a common issue among gardeners, whether they’re working in the dirt or starting seeds indoors.
What’s going on with your garden soil? If you see a green covering of algae on top of the soil in a warm damp and bright setting with moist and humid air, you’re more than likely dealing with algae. Algae thrives on soil that receives a lot of sunlight but is kept moist by excessive watering. High humidity fosters rapid growth in algae, which is why they are so common in greenhouses.
Algae may be eliminated and prevented without causing any harm to your plants, of course.
We’ll take a deeper look at algae and its habitats in this piece. We’ll also talk about how to keep it under control in the future.
Let’s get started.
Why Is My Garden Soil Turning Green?
Algae is the most likely cause of a green covering on top of your soil. At first, the green layer can be slick and slimy.
As the algae dries off, a black layer will form on top. The black algal crust, according to Clemson University, can prevent water from reaching the soil.
What Is Algae?
Biological creatures that have some characteristics to plants are collectively referred to as algae. All the way up to the enormous kelp and seaweeds, single-celled micro-algae are included in this broad category of algae.
The pigment chlorophyll is found in algae because, like plants, they undergo photosynthesis to convert light energy into chemical energy. Most algae are green in appearance, however brown and red algae are also seen.
Algae, despite their resemblance to plants, lack roots, stems, and leaves.
Check out Wikipedia’s algae page for more information.
Where Does Algae Thrive?
Freshwater and saltwater algae are the most common types of algae. There are a number of places where algae thrive, such as a greenhouse or on wet soil:
A moist atmosphere is more likely if there is little or no wind or air currents. The presence of algae is more common in enclosed spaces, such as a greenhouse or house, because of this.
Algae may thrive in any environment that has a significant amount of water. Moisture-absorbing substances often found in potting soil are included here, including:
- the moss of the peat bog (sphagnum)
To produce your own potting soil mix, check out my post on the subject.
Overwatering your houseplants can cause the small white balls of perlite in the potting mix to become green. Algae can thrive in a damp environment thanks to the perlite’s ability to retain water.
Algae thrive in regions that receive a lot of sunlight. They thrive in greenhouses because of this.
Gardeners who start seeds indoors under grow lights are more likely to notice “green mold” (algae) on potting soil because of this. As long as your garden soil remains damp and gets a lot of sunlight, algae are more than happy to develop on top of it.
68 to 86 degrees Fahrenheit is the ideal growing temperature range for algal blooms (20 to 30 degrees Celsius). If your greenhouse keeps this warm at night, you may be inviting algae to establish up a colony.
You can read more about algae’s response to environmental conditions in this Science Direct article.
Algae’s optimal pH varies depending on the type of algae in question. For instance:
- Algae like a pH of around 7.0 in freshwater (neutral)
- A pH of about 8.2 is ideal for marine algae (slightly alkaline)
- Spirulina (which may be eaten by humans) prefers a pH of around 10 (somewhat alkaline)
Check out Algae Research and Supply’s article on algae pH for additional details.
Unfortunately, most plants require a pH range of 6.0 to 6.8 in order to thrive (slightly acidic to neutral). Freshwater bacteria will be right at home in your garden or greenhouse because the soil is a natural habitat for them.
Unfortunatelly, modifying pH in order to kill algae will almost certainly result in damage to some of your plants. Make no mistake, there are ways to fix the situation (more detail on this later).
How Does Algae Spread?
Algae reproduce by dividing their cells. Spores are used by certain bigger algae to reproduce.
The top layer of soil on a seedling tray can become completely covered with algae if given enough time, moisture, and light.
Check out this Brittanica.com article on algae reproduction for additional information.
Some greenhouses’ translucent plastic walls are plagued by algae growth. Algae thrive in this environment because of the abundance of sunshine and lack of nearby competitors.
Fortunately, since algae have no roots, washing them away with a powerful hose spray is a straightforward task. Algae can also be removed using a sponge and soapy water and a mild detergent.
Will Algae Kill My Plants?
Because algae is not a parasite or a disease to your plants, it cannot harm them directly. Algae, on the other hand, can have a detrimental effect on your plants in a number of ways.
The first thing to consider is that algae competes with your plants for water and nutrients. Algae can cause a black crust to grow on top of the soil over time.
Water will be unable to reach the roots of a plant because of this crust. Regardless of how diligent you are about irrigating, you may observe the water “settle” on top of crusty green or black algae before it flows.
A heavy coating of algae on your soil, on the other hand, may cause mold or disease in your plants if it retains too much moisture.
How To Get Rid Of Algae
You may still want to get rid of algae, even if it doesn’t mean the end of your plants. For cosmetic reasons, you may also want to eliminate algae from your property.
If you already have algae in your garden or greenhouse, here are some techniques to get rid of it.
Dry Out The Algae
The best way to get rid of algae is to dry it out a little bit because algae flourish in damp circumstances. Improved soil drainage is one method of accomplishing this.
Algae growth is more likely if your garden soil drains poorly and is wet for an extended period of time. Soil drainage can be improved by incorporating compost into the topsoil.
Adding compost to the soil helps plants get the nutrients they need, as well as attracting earthworms and helpful microorganisms.
My article on bettering soil drainage has more information.
When it rains, some portions of your garden may remain saturated for days. Dig trenches and build pipes to channel water away from these trouble locations if you think this is the case.
Watering your garden in the morning instead of the evening should also become a habit. Because the soil remains damp at night when you water late in the day, it is more susceptible to disease.
The likelihood of growing algae, mold, and moss in your garden or greenhouse increases the longer the soil remains wet.
The likelihood that you are overwatering your plants should be taken into account as well. Algae growth will also increase as a result of this.
You may learn more about overwatering plants in my other article.
Change your watering approach if you are beginning seeds inside in preparation for spring. Instead of watering seed trays from the top, water them from the bottom.
By allowing the soil surface to dry out, this technique prevents algae formation and maintains seeds moist at all times.
You don’t need much more than a seed tray with holes in the bottom to water your seedlings. The tray should be submerged in water just deep enough to moisten the soil, but not so deep as to drown the soil completely.
In the event that you need to, you can use a metal shish kabob skewer to poke holes in the bottom of the seed tray (heating it up first would assist). Take care not to be pricked or burnt!
Decrease Light Levels
A common nickname for algae is “nature’s solar panels,” as sunlight is used to power them. Reduce the amount of light in the area where algae is forming if you wish to stop it.
Since your other plants may also be suffering from a lack of sunshine, this may be easier said than done. But if your lights remain on for 16 hours a day, you may be able to reduce the light intensity a bit in order to prevent algae growth.
Michigan State University has a great resource on algae, which you can find here.
How To Prevent Algae?
As soon as you remove the algae from your garden soil or greenhouse, you’ll want to take preventative measures to keep it from happening again. Algae can be prevented in a number of ways.
Use Potting Mix To Start Seedlings
Potting mix from the store, rather of compost or garden soil (“earth”), should be used if you wish to start seedlings indoors from seed. You could bring in spores or algae from the outside if you aren’t careful.
When growing in a greenhouse, you need to be especially vigilant since dust or dirt might be carried in by the wind and carry algae spores.
Check out this ProMix article on controlling algae on growing media for additional details.
If your seedlings have been plagued by algae in the past, a humidity dome may be an ideal solution. Check out my article on humidity domes for additional information.
Avoid Peat Moss, Perlite, & Vermiculite
These materials, as previously stated, retain a significant amount of water. The presence of peat moss, perlite, or vermiculite in a growing media makes it more likely that algae will flourish.
To learn more about perlite versus vermiculite, check out my article.
Avoid Over Watering Your Plants
Before watering your plants, make sure the top layer of soil is dry. Otherwise, a persistently wet top layer of soil encourages the growth of algae.
Drainage problems can be alleviated by raising the soil’s elevation (such as with a mound or berm). Soil drainage can be improved by elevating a bed, grow bag, or other container.
Use A Fan For Growing Indoors
Algae can be prevented by drying off the top layer of soil, so if you are beginning seeds indoors, try using a fan.
A greenhouse fan may also be useful in preventing the growth of algae.
What Is The Difference Between Algae & Moss?
Warm, moist, and light circumstances are ideal for the growth of algae. If the water contains significant concentrations of nitrogen or phosphorus, algae can develop there as well.
Moss, on the other hand, develops in dark, moist areas and creates a thick mat on rocks or dirt. Algae can grow on water, but moss cannot.
Why Should You Grow Your Plants in a Hobby Greenhouse?
The presence of algae might occur even if your plants are grown in a greenhouse, unless you take proper precautions. Algae, in fact, thrive in hobby greenhouses because they are able to absorb a lot of sunlight and avoid competing with other plants.
A pressure washer or hose with a powerful spray can quickly remove algae because they lack roots. You can also use a sponge and soapy water to manually remove them.
As a result, using a greenhouse to raise your plants is still one of the finest options. In the first place, it safeguards your plants from unpredictability of the climate. Strong winds, heavy rain, and storms can easily uproot delicate perennial plants. They are protected from the elements by being housed in a greenhouse.
Insect infestations can be minimized in a hobby greenhouse as well. Enclosed spaces will make it difficult for pests like aphids, mealybugs, spider mites, and cabbage worms to get in. Your greenhouse’s plants will continue to flourish.
How to Get Rid of Algae on Seeding Soil?
Now we get to the topic, “What can I do if my soil is covered in algae?” While repotting seedlings that are large enough may be possible, doing so could damage the delicate new roots. In order to avoid an algal bloom, you could also simply scrape or rough up the soil on the afflicted areas. There are a few natural antifungal therapies that you can try as well. Cinnamon can be sprayed on seedling soil to remove algae.
Final Thoughts on How to Control Green Algae in Your Soil
As a result of this information, you will be able to enhance the aesthetics of your garden or greenhouse. If you detect a green covering of algae on top of your soil, don’t panic. Algae does not harm your plants. You don’t have to worry about anything if you follow the advice outlined above!