This has been the coolest start to a spring that I can remember. That doesn’t mean there hasn’t been a cooler one, but this is the coolest one I can remember. If you know me, you realize my memory may not be the best, so that may not be saying much.
However, we are at least ten days, and probably more like two weeks, behind where we have been the past several years. The cool nights have impacted grass growth and budding of plants coming out of winter dormancy.
The impacts are numerous. Pasture growth has been so slow it has caused farmers to feed hay longer than usual. In some cases, hay supply has become very short due to the extended feeding.
In terms of what is best for the pasture, it is a mistake to put livestock on the pasture as soon as it turns green. Ideally, the plants need some time to grow and develop roots before grazing begins. Grass that is continually eaten off every time the blade grows never has opportunity to develop roots and become a competitive plant. Therefore, weeds have a great opportunity to get started.
An average height of eight to ten inches before beginning to graze would be ideal. Many pastures will not have that kind of growth when grazing begins and those pastures will see season long decrease in production because of the poor start.
Hay harvest typically begins in mid-May on the earliest cut fields. That is just two weeks from now and most hay fields are showing very little growth so far. I would anticipate first cutting will be delayed a couple of weeks, just as the start of growth has been delayed a couple of weeks.
Growing degree days is a measure of the buildup of heat from the beginning of the year. It is a useful tool to predict germination of plants. We have been using 200 growing degree days as the benchmark level to spray for invasive jointhead grass.
This is a pre-emergent spray, so the timing is important, as it needs done just before the plants germinate. We usually reach 200 growing degree days by April 15-20. This year, we won’t reach that level until the end of this week. So those that have a problem with jointhead grass can still spray and control it.
Biennial thistles is another plant that can be controlled with a herbicide application right now. The best time to spray these thistles is when the rosettes are coming out of dormancy in the spring. They are a little past that point and in some cases are starting to bolt.
However, it is not too late and with the slow grass growth, they are easier to find for spot treatment using a handgun sprayer or backpack.
A beneficiary of the cool spring should be fruit trees. The cool weather should delay blooming until we are free of frost. Our average frost free date is May 10. Based on the weather outlook, we may have seen out last frost.
Keep in mind, many of our warm season crops require soil temperatures of 50 to 60 degrees to germinate. Since it has been so cool, you may want to check soil temperatures before planting some warm season crops.