Fertilizing Grape Vines
What do you think of Kelp as a fertilizer for grape vine? I’ve got 50 grape vines; St Pipen, St Croix and Foch. What fertilizer is best?
Kelp contains .9% nitrogen, .5% phosphorous and 1 to 4% potassium and has been used for fertilizing ornamental and food crops. Sea kelp does contain sodium in several forms. No matter what fertilizer you prefer it is best to start with a soil test. This will tell you what type and how much fertilizer your grapes need. Your local University Extension service can provide information on how and where to have your soil tested. Plus many states are requiring soil tests before you can apply fertilizers containing phosphorous. If you skip the test consider with a low nitrogen slow release fertilizer like Milorganite. Most urban soils have high to excess levels of phosphorous and potassium. So before adding more make sure you need it. Many books and pamphlets recommend 10-10-10 fertilizers. The idea is to keep things in balance. But most plants do not use these nutrients in equal amounts resulting in a build up of phosphorous and potassium in the soil. So test first for best results.