I often get a call or two every year about fertilizing home muscadines. They are ideal for backyard production because they need a minimum spray program.
If you have just planted your vines then it is suggested to apply fertilizer three times during the first year. The first application will consist of a ½ pound of 10-10-10 or equivalent per vine. This first application should occur after the soil around each plant has settled. The second application of fertilizer will contain 2 ounces of ammonium nitrate per vine and it is best to apply in late May. In early July, apply 2 ounces of ammonium nitrate per vine. Broadcast each application over a 2-foot circle centered on the plant.
In the second year, the timing and method are the same as the first year. Gardeners should double the fertilizer rate for each application and increase the diameter of the broadcast circle to 4 feet.
If the vines have grown well the first two years and you expect a crop, apply 2 pounds of 10-10-10 or equivalent per vine in March. Then consider applying 1 pound of 10-10-10 per vine in May. Gardeners should broadcast in a 6-foot circle. If plants have not done well, fertilize as instructed for the second year.
If you have, established vines then consider applying 3 to 5 pounds of 10-10-10 or equivalent per plant in March of each year. Then apply ½ pound of ammonium nitrate around June 1.
Check the soil pH about every three years. Your county extension agent has kits for sampling. If liming is necessary, please use dolomitic lime because it contains magnesium.
Muscadines have a relatively high requirement for magnesium. Magnesium deficiency shows up as yellowing between the veins of older leaves. A result of magnesium deficiency is premature fruit fall according to the publication Home Garden Muscadines.
Well, how do I correct this issue? To prevent or correct magnesium deficiency, apply Epsom salts at the rate of 2 to 4 ounces for one- and two-year-old vines; 4 to 6 ounces for older vines. Be sure to evenly broadcast Epsom salts over a 3- to 6-foot area.
If you have any questions about this please contact your local county extension agent.