When you buy a Sargent’s Grown basket or tub this spring, you may notice a little paper packet on a stick. Nick likes to refer to them as lollypops, but they are called sachets within the horticulture industry.

These sachets are filled with predatory mites called Amblyseius cucumeris, as well as bran mites for a food source for the A.cucumeris to survive on until they are released among the greenhouse plants. Due to the food source and the different life stages within the sachet, they will continue releasing mites for about 6 weeks. 

These particular mites that we purposefully release go after Westerns Flower Thrips, pests that can damage the blooms of plants they reside on by piercing the cells of the surface tissues and sucking out their contents, causing the surrounding flower tissue to die. These twirps, I’m sorry, Thirps, prefer to feed on developing plant tissues such as growing tips and flower buds. When these tissues develop further, the leaves and flowers can appear grossly deformed. So our predatory mites go after them for dinner, leaving your plant to grow full, beautiful blooms.

Because A. cucumeris are so small (you can barely see them) and they do not fly, the sachets enable us to ensure that we can provide the same care to every crop. We also apply them to our floor grown crops by broadcasting them. After we broadcast them over the crops, they will crawl under the leaves of the plant and start hunting for Thrips!

When you bring your baskets or tubs home, you can remove the sachet if you would like to, the mites will have had plenty of time to leave the sachets. Unlike a pest like a spider mite or white fly, you do not need to worry about them ‘infesting’ your other plants because they do not feed on plants. In fact, you should be encouraged to let these little guys spread among your plants!

Another thing that I find neat about this is that many of these insects and mites used in greenhouse pest control occur naturally within the environment. As of right now, we do not release lace wings (they are an Aphid predator) but I find their eggs often throughout the perennials in the summertime.

Over the last couple of years, we have chosen to begin using more of these types of Biological Control Agents as it lessens our reliance on chemical controls and reduce our environmental footprint.

Cathy Maxson, Perennial Production Manager