> Later on in winter, with less time to wait till the return of spring, you could get away with a stack 30-60cm (1-2ft) in height.
One thing I hate about gardening articles and videos is they often use terms that are not consistent with different locations. Where I am in Northern Europe, what we consider 'spring' is going to be very different from what someone in Southern California considers 'spring'. 100 years ago where you audience is going to be in a small location near your printing press this may have been acceptable, but today when your audience is global it really is not.
Personally, in my locale March is usually when the crocuses start peeking out and the robins return... first signs of spring. But just 100 miles east the landscape might still be a winter wonderland well into April.
If I had to hazard a guess, this article was probably written with a British audience in mind, where "spring" loosely corresponds with March through May.
For planting people develop more nuance than just a binary season change. They look at the condition of soil, temperature, likely weather looking forward etc. Right now it is spring where I live. The soil is a bit wet and clumpy. We may still get a frost but probably won't.
And in the natural world things can be really spread out. Plants have different niches based on being early or late. Shoots will come up in the winter. And some plants will be dormant until much later.
So no one should write anything without accounting for everything?
I wonder what better term you think there is where spring is used? Like in context it obviously means the start of the growing season. The suggestion is thus that the technique would be used that way before the start of the local growing season.
Here we get several feet of snow and frost into May, so it might be something I would do now. It probably wouldn't work good in February when there's piles of snow and temperatures well below freezing.
One thing I hate about gardening articles and videos is they often use terms that are not consistent with different locations. Where I am in Northern Europe, what we consider 'spring' is going to be very different from what someone in Southern California considers 'spring'. 100 years ago where you audience is going to be in a small location near your printing press this may have been acceptable, but today when your audience is global it really is not.