Cool Season Pastures in the Summer
When you have cool season pastures, you know the intense, lush growth that occurs in the spring. You also know that your stands are cringing thinking about the summer heat that is about to set in. With summer comes slowed growth and multiple stressors like drought and heat being thrown at your stands of grasses and legumes. How can we minimize the stress on the plants? How does grazing have to change for this?
Rest, Rest, Rest
With all of the stress cool season pastures undergo in the summer, giving paddocks sufficient rest is the least you can do! Recovery in the summer months will be much slower than in the spring and fall as the grasses are less active, see the “Cool Season Perennials” line below:
This slow in growth is even more drastic in extremely dry or abnormally hot periods. With a slower recovery comes a need for longer rest periods. Take a look at the plants instead of your calendar when planning moves during the summer and plan ahead accordingly. Observe the density of the stand and take that into consideration as it will likely be thinner than when you grazed it earlier in the spring. In general, stands of grasses and legumes should be allowed to regrow to anywhere from 12-24 inches before being grazed again and always leave adequate stubble.
Did someone say stubble?
To ensure that longer rest and recovery period actually produces growth, a suitable stubble height must be left when a paddock is grazed. This can vary from species to species and can effectively be summed up by the “take 50, leave 50 method” shown in the first image below:
That being said, a critical height that should be left regardless of how much is grazed is at least 4-8 inches. That surface area that is left will allow quicker recovery when a hot or dry spell ends. This allows plants to pull less from their root reserves (days of stopped growth in image above). This makes your stand more tolerant when hot and dry weather conditions occur again and protect pastures from all the detriments of overgrazing.
In the same way that a stressed person or animal is more susceptible to illness and death, this summer's stressors can be damaging to plants. Providing adequately rest, recovery and stubble height can minimize damage from the hottest driest summers where cool season pastures exist.