• The recommended sowing dates for winter barley have already passed. Is it still worth trying to sow this cereal?
  • What risks are associated with delays in sowing winter barley? Or is there not much difference between early and late sowing?

The sowing window for winter cereals is fairly wide—in principle, they are sown from the first ten days of September until the end of November (although this is where a certain distinction begins: a winter crop or a crop that undergoes vernalization). The longest sowing window applies to winter wheat, which is due, among other things, to its ability to tiller. Wheat can postpone this most important process until spring, although research has confirmed that autumn tillering is the most productive. The number of tillers directly affects the number of ears per unit area. And this is where the first warning sign appears: how late we can sow winter crops depends on the tillering capacity of the particular species. Winter barley tillers only in autumn. It will not make up for any shortcomings in this respect in early spring—even if it has not tillered, it will not resume the process when spring growth begins. 

It needs time in autumn

In autumn, winter barley needs an effective temperature sum of around 400 - 450 ºC. However, the growing season unfolds differently each year. In autumn, during the 2023/2024 season, just 4 weeks after sowing, barley fields in the south of the country sometimes reached this threshold—this applied especially to fields sown early. Nevertheless, we may also encounter conditions in which it takes 6 - 8 weeks to reach this value and, consequently, complete the entire tillering process. Autumn growing conditions and temperatures are the most important factors in this respect. 

We have grown accustomed to being able to sow later, and to this being relatively safe. However, this is not necessarily the case—an earlier end to the growing season will not only force tillering to stop, but will also reduce frost hardiness. 

This year, one can observe that after the last difficult season, sowing dates are generally being approached with a little more care—we are most often trying to sow at the optimal time or shortly thereafter, at least where possible. Generalizing somewhat, this can be considered the right approach, since in this way we become less dependent on any lower temperatures in the second half of autumn and potentially too slow a rate of development.

Barley already weaker when sown at the end of September?

IUNG - PIB conducted research on the sowing date for winter barley. The conclusions drawn from the research clearly indicated that when winter barley was sown in the third decade of September, yields were lower than on fields established in the second decade of September. This applied to both heavy and light soils. The recommendations in the Integrated Production Methodology indicate that the winter form of barley should be sown by 15 September in the east, 18 September in the center, and 20 September in the south and west of the country. Some recommendations shift this date by a further 5 days—to 25 September in the southern and western regions, and 20 September in the rest of the country. What is more, a somewhat more liberal approach suggests that the date can be extended to the end of September in the warmer regions of the country and even to 25 September in the north. Let us note, however, that the aforementioned liberal approachto sowing is already quite optimistic, assuming a warm October and a relatively long growing season in November. Meanwhile, the sowing date cannot be postponed indefinitely. Taking older recommendations into account, at this point we are already about 4 weeks past the optimal date for barley in the north and east of the country, and even about 3 weeks according to newer recommendations. For southern Poland, the delay at this point is at least 2 weeks.

Barley sowing in October – possible, but it is late

If someone still needs to sow winter barley, it can be attempted, but note that the forecasts for the coming days generally do not show particularly warm autumn weather. This raises a warning sign: will the sum of effective temperatures be adequate? Will suitable conditions for tillering occur in autumn with sowing this late? And finally, will the barley be adequately prepared for potential winter frosts? Especially since it is the most delicate of the winter cereals.

Some barley growers try sowing even after grain maize harvested in mid-October. This can certainly succeed under favourable autumn conditions. However, it should be remembered that we are already talking about a significant departure from the so-called optimal dates. Even if the barley does quite well, yields may be reduced compared with sowing, for example, in the last ten days of September. The greatest opportunities for late barley sowing are still in the southwest of the country.

Winter wheat may now be an alternative. Sowing in mid-October or the second half of the month is still a surer option throughout Poland. And what about spring barley? It is worth noting that even winter barley sown later often yields better. However, for several seasons now, there have been trials of sowing spring barley in the second half of October and the first half of November. Opinions on this approach are mixed, but such sowing is intended as a kind of remedy and is meant, by design, to allow better yields than very late-sown winter barley.