Many Americans are worried that they might not have enough money for retirement. Women who outlive their husbands are at special risk, with 40 percent of widows living almost exclusively on Social Security. There are a lot of worried retirees out there. So, what are your retirement plans? Quality low-risk dividend growth stocks make an excellent addition to our retirement portfolio, and the good news is, you don't have to wait until you retire to figure out what income it will generate.

Below are several companies delivering more cash to their shareholders by raising their dividends:

Tiffany & Co. (NYSE:TIF) designs, manufactures, and retails jewelry and other items worldwide. On May 26 the company increased its quarterly dividend 12% to $0.45 per share. The dividend is payable July 11, 2016 to stockholders of record on June 20, 2016, with an ex-dividend date of June 16, 2016. The yield based on the new payout is 2.9%.

Canadian Imperial Bank of Commerce (NYSE:CM), a diversified financial institution, provides various financial products and services to individuals and small businesses; and commercial, corporate, and institutional clients in Canada and internationally. On May 26 the company increased its quarterly dividend 2.5% to C$1.21 per share. The dividend is payable July 28, 2016 to stockholders of record on June 28, 2016, with an ex-dividend date of June 24, 2016. The yield based on the new payout is 4.7%.

Extra Space Storage, Inc. (NYSE:EXR) engages in property management and development activities that include acquiring, managing, developing, and selling, as well as the rental of self-storage facilities. On May 26 the company increased its quarterly dividend 32% to $0.78 per share. The dividend is payable June 30, 2016 to stockholders of record on June 15, 2016, with an ex-dividend date of June 13, 2016. The yield based on the new payout is 3.8%.

Flowers Foods, Inc. (NYSE:FLO) produces and markets bakery products in the United States. It operates through two segments, Direct-Store-Delivery and Warehouse Delivery. On May 26 the company increased its quarterly dividend 10% to $0.16 per share. The dividend is payable June 23, 2016 to stockholders of record on June 9, 2016, with an ex-dividend date of June 7, 2016. The yield based on the new payout is 3.5%.

Unum Group (NYSE:UNM) provides group and individual disability insurance products and services primarily in the United States and the United Kingdom. On May 26 the company increased its quarterly dividend 8.1% to $0.20 per share. The yield based on the new payout is 2.2%.

Bank of Montreal (NYSE:BMO) provides diversified financial services primarily in North America. On May 25 the company increased its quarterly dividend 2.4% to C$0.86 per share. The dividend is payable August 26, 2016 to stockholders of record on August 1, 2016, with an ex-dividend date of July 28, 2016. The yield based on the new payout is 4.2%.

W. R. Berkley Corporation (NYSE:WRB), an insurance holding company, operates as commercial lines writers in the United States. On May 25 the company increased its quarterly dividend 8.3% to $0.13 per share. The dividend is payable July 5, 2016 to stockholders of record on June 15, 2016, with an ex-dividend date of June 13, 2016. The yield based on the new payout is 0.9%.

Donaldson Company, Inc. (NYSE:DCI) manufactures and sells filtration systems and replacement parts worldwide. On May 25 the company increased its quarterly dividend 2.9% to $0.175 per share. The dividend is payable June 29, 2016 to stockholders of record on June 10, 2016, with an ex-dividend date of June 8, 2016. The yield based on the new payout is 2.1%.

Bunge Limited (NYSE:BG) operates as an agribusiness and food company worldwide. It operates through five segments: Agribusiness, Edible Oil Products, Milling Products, Sugar and Bioenergy, and Fertilizer. On May 24 the company increased its quarterly dividend 10% to $0.42 per share. The dividend is payable September 2, 2016 to stockholders of record on August 19, 2016, with an ex-dividend date of August 17, 2016. The yield based on the new payout is 2.6%.

Cabot Corporation (NYSE:CBT) operates as a specialty chemicals and performance materials company. The company offers carbon black, a form of elemental carbon used to enhance the physical properties of the systems and applications in which it is incorporated. On May 24 the company increased its quarterly dividend 36% to $0.30 per share. The dividend is payable June 10, 2016 to stockholders of record on May 27, 2016, with an ex-dividend date of May 25, 2016. The yield based on the new payout is 2.7%.

Brandywine Realty Trust (NYSE:BDN) is a publicly owned real estate investment trust investing in office, mixed-use, and industrial properties. On May 24 the company increased its quarterly dividend 6.7% to $0.16 per share. The dividend is payable July 20, 2016 to stockholders of record on July 6, 2016, with an ex-dividend date of July 1, 2016. The yield based on the new payout is 4.3%.

PG&E Corporation (NYSE:PCG) transmits, delivers, and sells electricity and natural gas to residential, commercial, industrial, and agricultural customers primarily in northern and central California. On May 23 the company increased its quarterly dividend 7.7% to $0.49 per share. The dividend is payable July 15, 2016 to stockholders of record on June 30, 2016, with an ex-dividend date of June 28, 2016. The yield based on the new payout is 3.4%.

Selecting stocks with increasing dividends is critical for an income growth strategy. The above list contains stocks that recently raised their dividends; it is not a list of recommend buys. As always, due diligence should be performed before buying or selling any stock. For a list of stocks with a long string of consecutive cash dividend increases, see this list.