“Spring” might be too strong a word to describe conditions this year. As we see from Figure 1, we’re now officially the latest spring so far this decade, and about the same as the long-term average. Having said that, a good part of our Growing Degree Day accumulation has come from one warm day on February 21 and a couple of warm days from April 13-15. Apart from those days, GDD accumulation has been negligible.
Remember that the ovules of apple king flowers are only receptive for a short period of time, but the ovules of side blooms are receptive for much longer. This year in particular we may be depending on setting fruit on side blooms to achieve a full crop.
2018 Temperature graph