In general, muscadine vines are not heavy feeders and do not need much fertilizer after they are well-established. Too much fertilizer can stimulate wood and leaf growth rather than fruit production. Moderate amounts of fertilizer during the first and second years after planting will help stimulate young plants to size up for earlier fruit production.
Best Growing Conditions
Sun - The best and most muscadine berries will be produced when vines are growing in full to mostly sun. However, muscadine vines that receive a little shade will still produce good crops.
Soil Type Preferred - Muscadine vines can grow in a wide range of soil types. Well-drained soils produce the best growth and yields. Avoid soils that are persistently wet during the growing season. Highly fertile soils are not essential.
Soil pH - Muscadine vines will tolerate a fairly wide range of soil pH however prefer an acidic soil with a pH between 5.5 to 6.5. It's a good idea to test or have your soil tested to determine pH and nutrient deficiencies. If your local nursery and garden center does not sell testing kits you can buy a soil test kit online here. Or check with your local Extension Service to see if they provide soil testing services. Soil testing kits will include complete instructions for adjusting soil conditions. Depending on the results of the soil test, you can add lime to raise the pH or soil sulfur to lower the pH (make more acid).
Type Of Fertilizer
Planting Time - Never use manure of any kind at time of planting or around young muscadine plants. Sawdust, cottonseed meal or peat moss may either slow down growth, damage or kill the plants. At time of planting, never put commercial fertilizer in hole around roots. You can thoroughly mix in some bagged top or potting soil at a 25% or so ratio to condition dense clay soil.
Therafter - In general, Muscadine vines are not heavy feeders. These natives are right at home in the soil of southern gardens and can pick up the nutrients they need from the native soil. At the most, and after plants have become established, a light application in spring of a slow-release, non-burning organic fertilizer can be beneficial during the frist few years.
Watering Muscadine Vines
Once established, Muscadine vines are exceptionally drought tolerant. However, it is very important to provide adequate water during the first year when plants are establishing their root system. In the absence of regular rainfall, provide water as needed to keep soil moist during dry periods. In years therafter, provide supplemental water during the fruiting period when weather is dry. A two-inch layer of pine bark mulch is beneficial to conserve moisture and control weed growth.