Definition of seasons.
I have 2 questions. (1)There are 2 definitions for the seasons: astronomical and meteorological. For lawn and gardening purposes which definition should I assume when reading garden advice on the Web? (2) Is it too late to put down a herbicide to prevent chickweed germination? astronomical Fall starts Sept. 23 while meteorological Fall starts Sept 1
1. The meteorological definition. But keep in mind that the weather associated with seasons varies greatly from year to year--hence the expression that we are having an "early spring" or "late spring", etc. Gardening really has to work around that most of the time.
2. Not too late. Some winter annuals have already germinated, depending on their microclimate location. But, seeds keep germinating over the winter. They don't all germinate at once and finish for the winter, unfortunately.