Dormant Seeding vs. Spring Seeding
If you were not able to get all your seed jobs completed, we now need to weigh the option of dormant seeding. Keep in mind that the seeds won’t germinate until the soil warms in the coming spring. Generally, you want soil temps 40 degrees Fahrenheit or below. Assuming snow is not on the ground, one could continue through the winter.
There are a few factors that favor dormant seeding over spring seeding:
- Ground conditions. Often the ground is firm enough to handle equipment for seedbed prep and application without rutting. Spring conditions often are mucky and soft. Once spring conditions are suitable, the window for development before summer is short. This is especially true for native soils.
- Labor and equipment. These resources may be more available during the dormant seeding window than in spring.
- Some research has shown that dormant seedings will outperform spring seedings. This is particularly true with Kentucky bluegrass and, to some extent, tall fescue. They have a couple more weeks to develop than spring seedlings, which can be critical for summer survival. This is not as true with perennial ryegrass.
- Shaded areas can benefit from getting the seed in the ground during the dormant season. The seedling grass is allowed to develop before foliage is out on trees next spring.
- Typically, less supplemental irrigation is required.
- Weed and disease control regimens for dormant-seeded grass should be easier to implement than those in May and June.
Like most things, there are some drawbacks to dormant seeding:
- Seed rates. Research does vary, but typically, increasing seed application rates by 20-30% is recommended. So, it may cost a little more.
- An unusually early “spring” warm-up, followed by a cold snap, could lead to premature germination and then seedling death. This is a greater risk with perennial ryegrass.
- Erosion can be an issue. If you are seeding into the bare soil with a greater than a 3% slope, you may want to reconsider and do this work in the spring, late summer, or early fall. On relatively flat locations, definitely use mulch, such as straw, to cover any bare soil. This will protect seed and soil over the winter.
- Like any other time, performing successful seeding during the dormant season requires proper seedbed prep and seed distribution (these lead to good seed-soil contact). As mentioned before, use mulch where appropriate.
Moisture is also needed. Ideally, we will receive snow to provide moisture and cover during the depths of winter. With irrigation systems, for the most part, being winterized by now, getting water to the seeded ground before it freezes solid could be a task that just is not going to happen. If you can get some water to it, and if you remain dry, do so. This would be good for your new grass, which is up, and was planted in the last couple of months. This is also great for trees and shrubs.
Starter fertilizer applications can be delayed until near the time of germination next spring.
For weed control next spring, we have options. Corteva’s Defendor, which can be applied in late fall or early spring when temperatures are still cool, does not have seeding restrictions. FMC’s Quicksilver (carfentrazone) can be used 7 days after the grass emerges for broadleaf control. ArmorTech Trione (mesotrione) and BASF Pylex (topramezone) can be implemented 28 days following seed emergence for control of many broadleaf weeds and annual grasses. They work post-emergently as well as provide some pre-emergence control. Other excellent options contain the active ingredient quinclorac. These products include BASF’s Drive XLR8 and Nufarm’s Q-Ball. Herbicides, such as prodiamine or dithiopyr, are not recommended for use on dormant seeded areas next spring.
Dormant seeding is not a deadlock to succeed. However, there are situations where it is a viable alternative to seeding cool-season grass in the spring.