Organic mulches help reduce erosion and conserve water. They also help moderate soil temperatures and discourage weeds, helping tomato plants grow larger and healthier. While it’s possible to buy commercial material for this purpose, converting fallen leaves into natural homemade mulch is both more environmentally friendly and less costly. Papaya leaves are an especially good choice due to their large size and potential insect-repellent abilities. Collection
The average papaya leaf stays on the tree for four to six months, then turns yellow and falls off. Unlike many temperate climate trees, papayas do not lose their leaves in the cool season. Instead, they shed them throughout the year. You may need to collect the leaves and place them in a dry location for several months to produce enough mulch for your garden. If your papaya leaves seem to be falling off quickly, the tree may have a nutritional deficiency or disease. Shredding
Because papaya leaves can measure up to 3½ feet long and 2 feet wide, you must shred them before using them as effective mulch. You can place the leaves in a shallow pile and chop them with a lawnmower, put them through a wood chipper or leaf shredder, or shred them manually using garden shears or a machete. Ideally, the final product will be composed of many small, even pieces. Irregular leaf shreds usually take longer to break down into mulch and may be more difficult to apply to your garden. Composting
Leaf mulch is most effective when pre-composted. This process helps create a denser mulch that is less likely to blow away. It also starts the decay process, preventing the mulch from tying up nitrogen and other nutrients your tomato plants need to grow. Place the leaf shreds in a pile in a sheltered location. You can also use large plastic bags or open bins, as long as the leaves are protected from excess rain. Allow the leaves to compost for up to two years, turning the pile occasionally, until the material becomes crumbly and soft. Application
Apply composted papaya leaves to your garden about four to five weeks after the growing season begins, when the soil is warm. Tomato plants do best when mulched with 3 to 4 inches of coarse leaf compost. Place this material 2 to 3 inches away from the plant stem to reduce the risk of fungal infection or other disease. If the mulch compacts or breaks down significantly over the course of the growing season, add more to maintain the original depth. Considerations
Papaya leaves contain a substance called papain, which discourages insect attacks in live plants. Dry leaves tend to contain reduced levels of this substance, which can break down further in composted material. If you hope to discourage insects by using papaya mulch for your tomatoes, apply whole leaves in layers around the plant instead of composted material. Because these leaves have not decomposed before application, you may need to supplement your tomato plants with additional nitrogen to prevent deficiencies.