 No matter if you plant in March, April, May, or early June, the odds are high that your soybeans will begin flowering in late June or early July. Since sunlight is so important to soybean maturity, in the northern U.S., day length is longer than in the south. For example, in Fargo, North Dakota, on July 5th, there are approximately 15 hours and 45 minutes of sunlight. Miami, Florida has two hours less sunlight than Fargo.