By Blake Jackson
Spring is a common and preferred window for establishing forages in Pennsylvania, but persistent rainfall and unstable weather often complicate planting plans. As a result, many producers wonder how late spring planting can realistically continue and what alternatives exist if conditions prevent timely seeding.
The answer to how late it is “too late” depends largely on temperature patterns as summer approaches. Cool-season forages begin growing when soil temperatures reach about 40-45°F, perform best between 60-75°F, and slow down as heat intensifies. While cooler nighttime temperatures can offset warmer days to a degree, sustained heat eventually forces these grasses into summer dormancy until cooler fall conditions return.
Several assumptions help determine the latest viable planting window. Adequate but not excessive soil moisture is needed for germination and early growth. Temperatures should follow typical seasonal averages rather than extreme fluctuations.
Daytime highs above 75°F can be tolerated if nighttime lows remain below 60°F. Most importantly, new seedings should be established at least six weeks before prolonged warm temperatures occur, allowing plants to develop enough to survive summer stress.
Historical weather data shows that planting cut-off dates vary across the state. In some regions, average temperatures allow spring planting into mid-May, while other areas reach unfavorable conditions by late April. This variability makes local climate patterns an important consideration when making planting decisions.
If spring planting is not possible, producers should adjust expectations. Spring-seeded stands may produce only a single late-season cutting, with greater yield impacts appearing the following year.
When forage supplies are tight, planting summer annuals such as sorghum-sudangrass or millet can help fill the gap. These can then be followed by late-summer or fall seeding of cool-season perennials, giving the stand time to establish and return to full productivity without waiting until the next spring.
Photo Credit: pexels-binyaminmellish
Categories: Pennsylvania, Crops, Hay & Forage