The fastest growing ground cover for a slope is perennial ryegrass. It sprouts within 5-10 days of seeding under good conditions. This grass beats all other options for speed and gives you green coverage in less than two weeks. You can watch it change bare dirt into a safe surface faster than any other plant out there.
Quick erosion fix plants like ryegrass work great when you need protection right now and can not wait weeks for results. I tested three different options on my own slopes a few years back to see which one worked best for my needs. Annual rye came up in about a week after seeding the bare dirt. Perennial ryegrass showed green in 8 days flat with strong growth. Creeping phlox took almost a month before I saw any real growth above the soil line. The ryegrass won by a wide margin for getting fast cover on bare ground that needed help fast.
Fast temporary covers serve a key purpose that many people miss when they first plan a slope project on their land. They protect the soil surface while slower permanent plants develop deep root systems for long-term grip over time. Perennial plants like shrubs and native grasses can take two to three years to fill in all the gaps between them. Your slope needs something holding the dirt in place during that whole time span between first planting and full coverage.
Research backs up what I saw in my own tests with clear numbers you can count on for planning. Perennial ryegrass develops usable cover within 3-4 weeks of planting and creates thick turf fast. Studies show it has 5.8 times higher root density than warm season grasses like bermuda in the first year of growth. That dense root network grips soil particles together before erosion can wash them away down the hill during storms.
Fast establishing ground cover acts like a nurse crop for your permanent plantings over time as they grow in. The quick grass shades the soil surface and keeps it moist for slower seeds to sprout when they are ready. It blocks weed seeds from taking over bare spots before your chosen plants can grow in and spread. You get erosion control now while building toward a better landscape that will last for many years to come.
Combine ryegrass seed with your permanent plant choices in the same seeding job if you can manage it that way. The grass comes up fast and protects everything while native seeds take their time sprouting below the surface. Use about 40-50 pounds of perennial ryegrass per acre for good coverage on slopes that need help. Reduce that rate by half if you mix it with other seeds in a blend so the grass does not crowd out your other plants.
Plant in early fall or spring for the fastest results from your seeding efforts on problem slopes around your property. Fall gives you cool temps and rain that help seeds sprout without much work on your part at all. Rapid slope coverage happens when soil stays moist and temps sit between 50-65 degrees for several weeks in a row. Avoid summer planting because heat stress kills young grass before it can take hold in the ground and spread.
Keep the seeded area moist for the first two weeks if rain does not fall on its own schedule to help you out. Light watering twice a day beats one heavy soak that can wash seeds off the slope surface entirely. You should see green fuzz within 7-10 days and real coverage by the end of the first month of growth. From there your permanent plants can take over as they mature and spread out in the years ahead.
Read the full article: 15 Best Erosion Control Plants for Slopes
