Paul Nickerson

Archive for March, 2011|Monthly archive page

Potato Soil Tests: Fungus Gnats

In Pest Management on March 30, 2011 at 10:48 pm

Fungus Gnat Treatments

With the arrival of Spring come beautiful flowers, green grass, and Fungus Gnats! As the temperature warms, it is not uncommon to see small flies buzzing around the surface of the potting soil in your house plants. Small Fungus Gnats lay eggs just below the surface of the soil. Like most other flies, the eggs hatch into larvae which eventually pupate and become adults. The entire cycle takes about 30 days.

While these gnats can be fairly bothersome, they cause no real damage to established plants. The larvae eat organic material in the soil, including small, fibrous roots. Larger plants, with established roots, will not be greatly effected, however, seedlings, and succulents with shallow roots, may show signs of injury.

Potato Test

There is an easy way to test which plants are infected with the larvae. Cut a potato into small pieces and lay them on the surface of the potting soil which you wish to test. Be sure that the inside of the potato is in contact with the soil. Due to the small area in which I have my plants, I placed a few pieces in each pot. After about 48hrs, look at the area of the potato that was touching the soil. You will notice small larva crawling on the potato. Due to the concentrations of starch in the potato, the larvae will move from the soil, into the potato. While this is a great way to determine what plants are infected, discarding and replacing the pieces will continue to remove larvae from the soil. Unfortunately, due to the high populations of larvae, this is not an effective means by which to rid your plants of Fungus Gnats.

Group of Eggs

Once you notice that you have Fungus Gnats, there are a number of actions that can be taken to get rid of them. Fungus Gnat larvae prefer moist soil. As a result, when you determine which plants are infected, allow that plant to thoroughly dry out between waterings, this will kill any larvae, and will dry out any eggs in the soil. Removing the top half inch of potting soil and replacing it with dry sand will inhibit the ability of the gnats to lay their eggs in the soil.

Cider Vinegar Traps

Another effective treatment is to use Apple Cider Vinegar as a trap. Pour small amounts of Cider Vinegar into shallow containers. The fermentation will attract the adult gnats. When the gnats land in the vinegar, it will trap and kill them. With the high number of eggs that each fly can lay, it is much more efficient to kill off adults than try to purge plants of larvae.

While I used the potatoes to search for the larva of Fungus Gnats, the technique can be used to get an idea of what else is living in your soil as well. Here are some of the other fun things I found!

Notice the number of eggs...


Not sure what this little guy is..

Light Bulb Terrariums

In Potting on March 21, 2011 at 9:22 pm

Light Bulb Terrarium

Terrariums are a unique way to display plants in a way that captivates imagination and creativity. When designing and constructing a terrarium, one can create their own world full of colorful foliage. Designs can range from miniature rain forests to open meadows of moss. While many terrariums are created inside larger glass-ware, I want to take some time to show an interesting project I recently undertook.

Copper Tab Removal

When hollowing out a light bulb, it is important to wear protective gloves and eye protection. For this project, I selected a slightly large bulb, as it would give me more area to work with. Also, I was able to find a beautiful, clear bulb. If you are using a bulb that has a white powdered coating on the inside of the glass, you will need to clean it by pouring salt into the bulb and shaking it around.

Bulb Without Tab

To begin the process of hollowing the bulb, hold the bulb, upside down, firmly in one hand. With a pair of needle-nose pliers, remove the copper tag on the nose of the bulb. This should easily break free, leaving a small hole in the ceramic collar. With a small screw driver, or other pointed object, break away the collar. This can be removed in several pieces.

If the inner glass tubes did not break during the removal of the collar, it can be broken apart by inserting a screw driver into the bulb and moving it around. Carefully remove the glass pieces and wash out the bulb. Your terrarium is ready to set up.

Plants Inside Bulb

To balance my bulb, I placed a small amount of stones in the bottom of the bulb and positioned it to where I desired. I then funneled a small amount of succulent potting soil into the bulb. To position my plants I used bent wires as tools to manipulate the soil. It is important to research the plants you are putting in your terrarium to ensure that your desired plants are compatible. I will talk more about selecting plants and setting up larger terrariums in my next post.

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