Plant Magic - Oldtimer Organic PK 4-8Finally, an Oldtimer Organic PK Booster! Plant Magic Plus Oldtimer PK 4 8 gives your plants the phosphorous and potassium that they need to increase weight and improve essential oil content but, unlike its competitors, it's made using certified organic materials. Plant Magic Oldtimer products encourage beneficial microbial activity in the root zone. This increases yield and root health. For a really flourishing microherd we highly recommend using