Fertilizing through an irrigation system is referred to as "fertigation." Historically, the products used in fertigation (known as “injectables”) have primarily been conventional (non-organic) or, if organic, uneconomical. These limitations have been minimized now that micronized organic fertilizers have been developed. Foliar fertilizers can be applied through irrigation lines, but you must increase the foliar rates by at least five times. To denote which fertilizers are appropriate for injecting, we have indicated them with an i for “injectable” and they are listed as such on our Fertilizer Solutions Chart. Most fertilizers in this section are injectable, but please note which of these products are dry and must be premixed with water before being injected. Irrigation lines should always be cleaned after fertigation by flushing with clean water before and/or after fertilizing. Use Therm X70 when flushing irrigation lines.