Timing is Everything

Flourishing Fields

Aerial view of recently grazed rotation at White Oak Pastures in Bluffton, GA.

When it comes to rotational grazing, timing is everything.

Of course, preparation is essential. As discussed in past posts, we’ve tested our soils, planned stocking densities and calculated paddock sizes.  But the real key to maintaining flourishing fields is the timing of moving animals through them—both how long a herd is in a paddock, and how long we let the grasses recover before bringing the herd back. And while we’re ultimately raising animals, the focus here is on what's best for the plants. Put simply, we want to minimize the time plants are being grazed and maximize the time plants can recover.  

Let’s start with grazing duration.  In wetter climates like ours, we can keep our animals in a paddock for up to three to four days, tops.  Any longer, and you’re damaging your grass. That’s because, within just a few days, plants will tap their stored reserves to send out tender new leaves, and if our herd is still in the paddock, they’ll eagerly eat the fresh growth. So it’s essential to move animals off the paddock before there is new growth for them to eat, which ultimately saps your pasture’s vitality.  

Besides being better for the plants, moving animals off a paddock within a few days also maximizes forage utilization. If the herd stays longer, they’ll over-trample the pasture, concentrate nutrients from their manure and negatively impact the pasture through increased compaction and bare spots.  

There will be times that grazing can be extended (we’ll talk about these in future posts) but when writing our grazing plan, we should expect to move animals within three to four days. For farmers with off-farm jobs or limited time, planning to move animals to fresh pasture twice a week allows for predictable scheduling.  And with a little upfront investment in temporary fencing, two or more paddocks could be set up in one day. 

Multiple paddocks set up at once may facilitate daily moves and the farmer’s schedule.

A common question regarding timing for the year is, “when do we begin grazing a paddock?” If measuring the canopy height of the grasses, plan to begin grazing most of our cool season grasses when they’re at least 8” high (bluegrass can be grazed at 6”) and warm season native grasses when they’re 12” high. Warm season grasses that can cause prussic acid poisoning (e.g. sorghum sudan) shouldn't be grazed until they are at least 24" tall. Counting full leaves of plants can also inform when plants are ready to be grazed.  Plan not to graze until the grasses have at least three full leaves. Remember from our last post that we should have sized each paddock so the animals have enough available dry matter to feed them for a pre-planned amount of time, while also leaving the plants with at least 4”of residual leaves to begin their recovery.

At least 4” of residual left for grazed plants to begin their recovery

The timing for plant recovery is the most important consideration in determining when animals can return. The plants need to re-grow to at least 8” tall (3 full leaves). For planning purposes, begin with typical recovery times and adjust as needed as the season unfolds. During the spring flush, cool-season grasses recover so quickly that we can return animals to the paddock after just three weeks of recovery time since the initial grazing. During the middle of summer, when cool-season grass growth has slowed, perhaps even gone dormant, we should wait approximately 8-9 weeks between grazings. Cooler fall weather again allows for quicker plant recovery (not quite as fast as in spring however) and we can be back grazing a paddock within 4 weeks of its last grazing. 

Backed by science, these guidelines help us set the framework for the all-important rotation of animals through our pastures. And while it may seem simple, it is arguably quite complicated. And like many complicated subjects, the artful implementation and improvisation of rotational grazing adds vitality. In our next post we’ll talk about the adaptive art of multi-paddock grazing, beginning with introducing and managing planned disturbances to help our fields flourish. Please reach out with feedback or questions. We’re here to help!

Read the previous article: Grazing animals are good for the grass

Craig Haney

Chaney@northjerseyrcd.org