How to Treat and Prevent a Spider Mite Infestation
Spider Mite In Action
What's the Cause of Houseplant Webbing?
Have you noticed your beloved houseplant is suddenly displaying a great deal of eerie mysterious webbing? Have you wondered how that webbing got there? Is it a spider perhaps, or could it be something more malevolent?
It is possible that the webbing is from a spider, but most likely, if you have seen a lot of webbing on your plant, and the plant has exhibited some signs that it is not healthy with yellowing leaves, many brown and crunchy leaves, and leaves that are stippled with discoloration, your plant most likely has been infested with a common houseplant pest; spider mites.
The spider mite is a very tiny insect that has eight legs like a spider and has many of the same characteristics as a spider. It is very tiny, incredibly prolific, and lives in a community with other little industrious spider mites. Once they infest a plant, they can form an entire bustling colony on that plant in a week, sometimes less depending on the environmental conditions. Spider mites will spin webbing all over the plant that they infest. Once they have created enough webbing to be noticeable, they have established a fairly large and prosperous community. Since the mites are so small, they are difficult to notice by most people until they really have done some significant damage.
Spider mites both live and feed on the houseplant that they choose to infest. They have tiny piercing mouth parts with which they bite into the plant cells of leaves to suck out the chlorophyll. As spider mites feed on the precious chlorophyll (the stuff that makes a plant green, and allows photosynthesis to occur) plant cells become damaged. The plant leaves will display a rough yellowing as they lose chlorophyll and cell walls are being punctured. All of this causes incredible and unsightly damage to your houseplant.
How to Treat a Spider Mite Infestation
Now you know that you have a colony of spider mites on your houseplant, is there anything that can be done to stop the spread and save your plant from being eaten alive? Absolutely!
In order to get those mites off the plant, try these methods:
- Regularly rinse or spray the leaves off with cold water (mites hate both cold and wet) this will often wash many away.
- Hand wipe all of the plant leaves with a wet sponge or baby wipe.
- Spray or Wipe the plant down again with a light solution of dish soap and water. A soap called is also very effective and non-toxic for use in such situations. Use approximately 1/2 tsp soap to 12oz water. Dr. Bronners
- Avoid placement in a hot dry place. Spaces near an open window, door, or by an air vent should be avoided. If your plant is currently in such a space move it to a cooler place with less airflow. (Mites love hot dry conditions).
- Use Neem Oil to wipe down the foliage of your plant. Neem oil will place an additional barrier on the foliage that is offensive to the mites, and as an added bonus will make your plants very shiny.
- Leaf Shine can also provide an additional preventative barrier against Mites. Leaf shine should be used with discretion as too much can build up on the foliage and damage it. The best leaf shines are those that are in liquid concentrate to be combined with water. Aerosol Leaf Shines can be heavy and difficult to evenly apply.
- A product called Pro tekt has had beneficial results in defending against Mites. It is watered in to the soil and absorbed, it then serves to strengthen a plants cell walls, making it much more difficult for a Spider Mite to bite through the cell to get to the Chlorophyll.
After these steps have been taken you should repeat some or all of them regularly, as mites have an uncanny knack for regaining their stronghold. Periodic hand wiping is really the most effective as it will crush and remove any spider mite squatters, and using the soap provides a new refreshed protective layer for the foliage.
Common Houseplants Susceptable to Spider Mites
Spider mites are preventable, detectable, and controllable. Certain types of plants are irresistible to Spider mites and are very prone to infestation. Here is a list of a few that are well known to easily become infested.
- Cast Iron or Aspidistra
- Dracena Marginata
- Fishtail Palm
- Bamboo Palm, Parlor Palm
- Lucky Bamboo
Detecting and Preventing Spider Mites
Mites love hot and dry environments. You are almost guaranteed to have a mite infestation if you place one of the plants listed above in direct sunlight.
- Placing plants near or over a heat vent or fireplace.
- Placing plants near windows or doors that open to the outside, especially if you live in a low humidity area.
- Leaving houseplants outside.
To check for spider mite, take a paper towel, baby wipe, or something of the like and wipe the underside of the leaves on your plant (I recommend doing this if you have any of the above listed plants for sure) If you see green residue on your cloth after you have wiped, you have spider mites. You can also rub your fingers across the back of a leaf (this works well for cast iron) if it feels grainy, you probably have an infestation. Remember that by the time webs are visible the mites have overtaken the plant, it is best to detect them before they get to the noticeable webbing stage for the health of your plant.
Avoiding the conditions that mites like, cleaning your houseplants regularly by hand wiping with dish soaps, insecticidal soaps, or Neem oil (especially for the plants listed above), are the best preventative steps to take in the war on spider mites.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
Questions & Answers
Can you get rid of an infestation by following the steps in the article? The rubber tree plant in my bedroom has webs on the leaves, a yellow residue on the top layer of soil, and a mysterious hole in the soil near one of the stems. Can you help?
The steps outlined in the article for treating Spider Mite will work for a Rubber tree. I believe that the yellow residue on the soil you are describing is unrelated to the Spider Mite, it is more likely a build-up of fertilizer or a soil fungus on the soil surface. The mysterious hole in the soil is also unlikely to be related to the gnats, it sounds more like there might be an earthworm in the pot which has been known to occur on occasion. If there is an earthworm it should not do any harm.Helpful 4
Should I dilute neem before cleaning plant leaves with it?
Concentrated neem oil is too caustic to put directly on plant leaves. It should be diluted with a mild mix of water, and dish or organic soap.Helpful 10
Once I remove the spider mite infested plant from the soil, is the soil still infested?
Good question! Spider Mite is very prolific on plants that are susceptable to it. It is thought that the pests are either in some way already on the plant, or exist in the environment and are attracted if conditions permit. Given the environmental belief, I would say that there is a possibility that they can remain in the soil in some form, and are definitely present in the area. If Spider Mite has been a problem and you wish to replace a plant where there has been an infestation, replace everything, and try to replace with a plant type that is less susceptable to Spider Mites.Helpful 19
How often should you use neem oil to protect Dracena Marginata?
If a Marginata plant is in a hot, dry, brightly-lit, or high airflow environment it is at risk of attracting spider mites, but it can be safely treated with neem oil about every two to three months.Helpful 10