The results are interesting and you don't need to use liquid nitrogen to check what happens. You can just put a banana in a home freezer and leave it there for at least 24 hours to be sure that it is completely frozen. Take it out and check what happens as it warms up.
In some parts of the country, spring is the best time to plant alfalfa. In others, it can be done successfully in late summer and early fall. It needs six to eight weeks of growing time before the first frost so it comes back with gusto in the spring. {C}.
When to Apply: Apply in early spring to prevent crabgrass all season long. For most areas this is going to be from early March until mid May. So it can vary from March 1st-May 20th. Crabgrass seeds can germinate when nighttime soil temperatures reach over 50 degrees for 3 days.