See white, cream, yellow, or gray spheres in your soil and you’re not sure what they are? We’re here to help!
In many of our houseplants, we use slow-release fertilizer prills (non-geeks might call these pellets). These prills slowly add nutrients to your potting soil, ensuring your plants have an even supply of nutrients so they can grow healthy or strong. Depending on the fertilizer formulation, these prills may be white, yellow, green, or cream. They’re typically distributed throughout the soil and if you squish them, liquid fertilizer squirts out. (If you do this, be sure to wash your hands immediately afterward.) Bonus: In addition to helping your plants by making sure there are always nutrients being released into the soil, slow-release fertilizer prills help us improve the environment by eliminating fertilizer runoff.
Perlite is essentially a popped volcanic rock we use in many of our potting mixes to increase drainage and aeration. It’s almost always white (though over time can become stained). If you look closely, perlite tends to be irregularly shaped and in a variety of different sizes. If you pick up a piece of perlite between your fingers, it will feel rough and firm.
Pest eggs are generally laid together in a cluster, rather than dispersed through the soil. Most pests lay eggs that are much smaller than fertilizer prills. And if you pick them up, they won’t have the firm “shell” that a fertilizer prill will—they’ll be soft and usually slimy. Happily, pest eggs in the soil are rare compared to fertilizer prills and perlite!