The best mulch for any garden is one that is available and improves the soil. Vegetables and roses are such hungry plants that I like to use a mulch that adds nitrogen such a composted manure or a good compost. Pine straw can make your soil more acidic, and veggies like a soil that is more on the neutral side. Pine straw is perfect around acid loving plants like rhododendrons, azaleas, camellias, and blueberries. Keep growing, Marianne Binetti