|We do combine shipping for seeds. All seeds are Flat Rate for as many packs as you want. A seed is a live product which depends on many important related grower skills such as proper planting time, seed depth, type of soil, irrigation, proper use of fertilizers, weed controls, fungicides, insecticides, disease free soil, and reasonable weather conditions during the growing period. Germination is affected by such factors as temperature, moisture content, light intensity, and contamination of planting media. These factors are totally out of my control and are your responsibility and risk. Consequentially, I cannot unconditionally guarantee seed to perform properly regardless of conditions or the buyer's methods.