Question
I have several house plants including a huge norfolk pine, a very large jade, one cactus and some unknowns.  I've had some of these plants for as long as 8 years and never had any problems.  Unfortunately, I bought a new plant in a grocery store and a month or so later noticed bugs that looked like teeny gnats flying around the plant when I watered it.  A couple of weeks later, I noticed tiny, almost invisible, white worms in the soil.  Of course I threw the plant out immediately but it was too late.  Now all of my beautiful plants  have the same thing.  I tried using an insecticide that I purchased on all of them, on the leaves and the soil.  They've had three treatments - all two weeks apart and the pest are less than they were but they are still there and my jade is now dropping leaves.  Is there any natural remedy?  Is there any hope for these plans or do I have to throw all of them away?

Answer
Hi Pattie
Boy o boy, do I sympathize with you; a few weeks ago, I too bought a houseplant at a grocery store.  It was LOADED with scale!  I called the store immediately and told them.  They returned my money to me, I threw the plant away-they did not want it back.  I treated all of my plants right away.
The gnats you are talking about are called 'soil gnats'.  They are very common, especially when you are talking about plants purchased by grocery store type places. The gnats thrive on the organic matter in damp soil.  When you have a large group of plants, as in a grocery store, they will jump from one plant to the next. Usually, grocery stores tend to keep the soil of the plants soggy.  Soil gnats do not do any damage to the plants-they are more of a pain to us, flying around our faces, etc.  You may also notice if you leave a glass of water or something sitting out, they will fly into that.
*A word of advice; when purchasing a new houseplant, no matter where you buy it-always isolate it before setting it out among your other established plants.  That way, if it is infested with something, it will not be passed along.  I always set mine in a spare bedroom for a few days.*  
Were the worms just in the newly purchased plant or in all of your plants?    
There are a couple of options you can try for the soil gnats:

****Depending on how many plants you have and the size
    of the pots, you can try putting the plants into
    large trash bags, securing tightly, for a couple
    of days.  This will suffocate the gnats.  This
    mainly works well on 4" or 6" potted plants.

****You can try allowing the soil to dry out a bit more
    than usual.  The gnats will not survive without
    the moisture.

The following are for both the gnats and the white worms.

****A systemic can be used in the soil.  This is purchased
    at your local nursery.  It is a granule that goes
    into the soil.

****You can mix a bit of dish soap, rubbing alcohol and
    water-about 1 tsp. per pint-into a misting bottle
    and mist the plant and soil with this.  This does
    work great for the gnats especially.

If you have your house exterminated monthly, as I do, do not allow them to spray your plants!  I had a guy see the soil gnats flying around and he sprayed all my plants.  They all died within a week!  

Good Luck Pattie, I know how aggravating this can be!

Leslie