Annual vs. Perennial Ryegrass:
If you plan to overseed your lawn this fall, knowing the difference between annual and perennial ryegrass, and how each one performs, will help you make the best choice for your situation.
Perennial ryegrass has a deep green color and slower growth habit. Even though it has the word “perennial” in its name, in full sun, this cool season grass will fade, and your permanent turf will flourish when temperatures warm and consistently reach the 90s. In the shade however, it may stay cool enough for perennial rye to persist into the summer. Use of a specific variety is not that critical. Most are packaged blends of 2 to 3 varieties best adapted to a particular region.
Annual ryegrass is much less expensive than perennial rye. However, it takes on a pale yellow-green color when soil temperatures cool and it must be cut more often than perennial ryegrass. The best use for annual ryegrass is for large area coverage and for erosion control. It may also be used as a temporary lawn while waiting to install permanent Bermuda grass or St. Augustine grass once temperatures warm. Commercial properties and landscaping contractors prefer to use perennial rye for overseeding. It is imperative that a pre-emergent not be used prior to seeding either type of ryegrass, as this will inhibit the development of the seed.
The next step is to drop the mower setting a couple of notches and cut the lawn. In Bermuda grass, especially, this exposes mostly stems and causes the lawn to look brown. This is more challenging to accomplish in St. Augustinegrass because of its wide leaf blades, but this process is essential as it allows the ryegrass seed to contact the soil, which is critical for germination.
Use approximately 8 – 10 pounds of ryegrass seed for every 1,000 square feet of lawn area, being careful not to get the seed in your flower beds. Two to three passes with a drop spreader open to its widest setting will create a buffer zone. Then use a broadcast spreader to finish the seeding.
After seeding, apply a 20-5-10 or a 15-5-10 fertilizer with half of its nitrogen in a slow-release form at half-strength. Once the seed has sprouted, maintain the deep green color throughout the growing season by fertilizing at the regular rate in late November and early February…one pound of actual nitrogen per 1000 square feet.
Once the seed and fertilizer have been applied, keeping the seed moist so germination can occur is your next objective. Water once or twice a day, 5 – 10 minutes per area, but do not let the water puddle. In three to five days, in warm weather, new seedlings will start emerging. When the new seedlings are about an inch or so tall, decrease the watering to every other day, but increase the amount of time for each area. Gradually cut back your number of days to once a week, applying an inch of water if no rainfall has occurred. November through February, check the soil’s moisture, and if the top inch of the soil is dry to the touch, irrigate.
A good mowing height for ryegrass is 2 – 3 inches. It is best to mow again before it reaches a height of 3 – 4 inches. This may only mean cutting the grass every two to three weeks when the weather is cool, more often however in the spring. Timely mowing will have a positive effect on health, vigor and weed suppression.
In an overseeded lawn, weeds usually are not a major concern. Cool season broadleaf weeds will be the main culprit and are usually controlled with an herbicide. Apply the weed control following the label directions, but only after the lawn has been mowed at least three times. Use a dedicated spot sprayer on a sunny day when temperatures are between 55 – 85 degrees and winds are light. Spring pre-emergents for Bermuda and St. Augustine grass will still be applied at their normal times of March 1st and June 1st.
Planting ryegrass in the fall really brightens the landscape and gives tired lawns a new refreshed look. It is especially effective for homes on the market for sale during the winter…the lush lawn makes them look appealing and well cared for.