Ask SAM: Time grass planting with early thaw

This column is provided by Larimer County Extension's Small Acreage Management (SAM) Program to assist rural residents.

Dear SAM,

I was planning to plant grass seed this winter, and then the heavy snows fell. Parts of my future pasture are still covered with snow. I'd like to take advantage of the moisture, but am worried I won't be able to get seed in the ground early enough this spring. Is there hope?

K.G.

Dear K.G.,

Your plans made sense, but the weather rarely cooperates.

Dryland grass should be planted between mid-November and late April. Seed is planted into cold soil to prevent germination before harsh winter conditions set in. This is called a dormant planting, as the seed is expected to remain dormant, or "sleeping," until good growing conditions arrive in the spring.

Our heavy snows came in mid-December, making planting impossible during the past two months. The snow could represent a great opportunity to establish dryland pastures, as soil moisture could be favorable this spring. But if seed isn't in the ground, it will be an opportunity lost.

Consider a no-till planting approach. Hire a contractor with a no-till grass drill that is capable of planting seed directly into unplowed ground. The drill slices a slot into the ground into which the seed drops. Press wheels then run over the slot, closing and packing the soil over the seed.

Drilling grass seed into frozen ground is not recommended. On frozen soils, the press wheels are unable to close the slot and cover the seed. Instead, the seed tends to lay exposed in the slot. Without soil cover and good seed-to-soil contact, the seed could fail to germinate or, if it does germinate, quickly dry up and die.

As the soil thaws, the biggest concern is driving on wet soils and causing compaction. If you drive over the field and wheel tracks remain visibly sunken, the soil is too wet and you should stay off.

The best time to plant this spring could be shortly into the thaw. The ground thaws from the surface downward. When the top 1 or 2 inches of ground are thawed, the seed drill will be able to get good seed placement and coverage. The deeper, frozen soil will be stable enough to prevent excessive compaction.

Of course, finding a contractor to show up on the perfect day is a challenge. If you miss the window during the thaw, wait until the soil has dried sufficiently and plant later in the spring. You'll risk missing some spring moisture, but you'll prevent soil compaction and a muddy mess. A later planting might also give you a chance to control spring weeds before seeding.

SAM

Have a question about rural living? Write to Ask SAM, Larimer County Cooperative Extension, P.O. Box 543, Fort Collins, CO 80522.