“I have the plague!” a fellow gardener recently wailed. “Whitefly! The only solution is to kill everything and burn it.” But then, another gardening friend, Pat, bounced in and announced she had just beaten white fly.
Pat has a greenhouse (which is where whitefly truly is nearly impossible to eradicate), but I think her method would very likely work outdoors as well, so here is what she told me.
Pat’s WhiteFly Recipe
Pat wanted to deal with her problem 1) organically, and 2) cheaply. A first-class Google fan, Pat does a lot of research on the net. That’s where she saw Neem Oil mentioned as effective in helping to control whitefly. While the processed oil is a trifle expensive (around $20 for 16 oz., not to mention shipping), Panama is full of neem trees; they line the roads and drop seeds by the truckful.
Realizing she had no way to process the seeds to extract the oil, Pat decided to try an alternative method. So she gathered about a half pound of green neem seeds and threw them in the food processor with a little water.
To the resulting stinky mess, she added a bit of cooking oil and a couple of squirts of liquid dish soap.
She assured me that the result was thoroughly disgusting and smelled to heaven.
First, she tried diluting this and spraying it on a plant. It proved an extremely effective herbicide. The plant died.
But she noticed that the whitefly avoided the area near the dead plant.
So, holding her breath against the stink, she cut the bottoms off some soda bottles to make shallow dishes, filled them with the neem mix, and nested them flush with the soil among the affected plants.
First she noticed a lot of bodies in the little dishes, and then, “The whitefly LEFT, JK! They just left!”
Apparently they couldn’t take the smell either.
So far, she says, they haven’t come back. She hasn’t found any eggs, and there isn’t a sign of the little fliers.
This could simply be the result of good karma, or it could be that green neem seeds actually do the trick. It’s doubtful this method will ever become commercially viable because of the stink, but as a homemade solution for the desperate, it sounds fine.
The neem are blooming right now, and I have seen seed on the trees, so I’m going to gather some and have it on hand, just in case. Since I am going to want it in the green state, I’ll try freezing it.
For those of you living where neem trees are not common, you can always try the oil. Although not as effective as Pat finds her method, apparently it interferes with egg-laying and development, so it interrupts the life cycle and reduces the population. For economy, you can buy it as a pesticide concentrate and spray it on. “It doesn’t kill them all, but it does reduce their numbers.” (And if you sprayed preventatively, maybe the eggs wouldn’t hatch and you wouldn’t have a problem.)
Pat also tells me that sticky traps, which have the advantage of being available everywhere, are helpful. (And surely satisfying, if your rage against the whitefly for eating your harvest is at all elevated.) You can buy them on Amazon, or you can make your own. The basic DIY involves yellow cardstock coated with petroleum jelly. Outdoors, you can paint a board or a stick yellow and coat it with the jelly. When it’s full of dead bugs, just wash it off, and apply new jelly. Here’s a video of an upgraded sticky trap using petroleum jelly coated cardstock in combination with a yellow light bulb.