Later harvested bulbs will taste sweeter.
Yes, but then the question becomes : Later than when? Assuming the Dutch data is correct, the clock begins at about 10°C(50°F) sustained temperature. When does that happen?
It would be the bulb in the ground temperature that counts, not the air temperature above. Soil temperature at depth where a bulb resides doesn't vary so quickly. I'm sure the relationship between factors like soil type, moisture, climate, geographic latitude, etc., is important. I checked this morning and here in zone 4 Minnesota:
At 6 inches down it was 59-60°F (different places in the yard)
At 3 inches down it was 52-57 °F
Air temp: 48°F
Soil temperature is a relatively new area of study for me. Do these temps seem right to you, Lorn?
So if all this data is accurate enough, harvesting a bulb Sept 1 or today, Oct 6, would make no difference. The trick is exposing the bulb to that "magic" temperature range.
