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}.
You can start your seeds indoors or you can buy broccoli plants from the nursery. Plant the broccoli seeds indoors about 6 weeks before you want to plant them outside. They can be planted in the garden about 3 weeks before the frost-free date. See Vegetable Planting Guide.