Strain and add that to a 2 gallon watering can and apply to everything outdoors. If you plan to use it indoors or in the greenhouse omit the garlic. This will fight red spider, white fly and aphids of all colors.
Soap is another big help in discouraging plant pests. My mother always used fels naptha soap which is still available on grocery store shelves in the laundry soap area. I use the shavings from our homemade soap. Soak ¼ C soap shavings in 1 quart of water. Mix thoroughly and store in a lidded jar or in a spray bottle. Shake before use. It is easy and effective especially for white fly and scale. Another old timer who tipped me off to using this soap spray for white fly said in his deep PA Dutch accent “It gums their wings together now– no fly, they die”. We have the largest citrus grove in
of boiling water (to cover) and infuse over night. Strain, pour into a sprinkling can, fill with water and use on infected plants. This is especially good against white flies, woolly aphids, squash bugs, potato bugs and beetles on radishes.
The effects of marigolds (Tagetes spp., not Calendula) upon nematodes a destructive invisible soil organism that causes great losses, was observed in the great bulb fields of Holland where, after one year of growing the spicy marigold (Tagetes erecta) the fields were found free of this dreadful pest for seven years. We rotate plantings of this colorful plant in different sections of the garden as a cheery preventative measure against nematodes.