With less than one month left before the tax-filing deadline, it's time to fund a Roth IRA if you haven't done so already. Let's briefly discuss why a Roth IRA is so essential in saving for your retirement. Then we'll look at three great growth stocks for your Roth.

See you later, Uncle Sam
A Roth IRA is one of the best ways to save for retirement. You contribute after-tax dollars to a Roth in exchange for tax-free earnings. You have until the April 15 tax-filing deadline to make your contribution for 2013. Before contributing, familiarize yourself with Roth IRA rules and eligibility requirements.

Stocks for the growth investor
For investors seeking growth, I've narrowed the stock universe down to three great companies, all boasting exciting growth prospects and competitive positions in their respective industries.

Zoetis (ZTS 1.64%)
The world's largest animal health company, Zoetis serves the farm and companion animal markets, which both offer attractive growth potential. Rising populations, a growing global middle class, and higher-protein diets in emerging markets support demand for livestock health products. Companion animal health should benefit from increasing pet ownership and the willingness of pet owners to spend on Fido's medical care. In fact, pet expenditures in the U.S. reached a record $55.7 billion last year. Relative to the human pharmaceutical industry, animal health benefits from fewer regulatory restrictions and less generic competition.

Zoetis' revenue has averaged annual growth of 2%, and earnings have averaged 15% over the past year. The company's recent P/E ratio has been around 38 -- just half the industry average of about 76. Zoetis' forward-looking P/E, based on next year's earnings, is less than 17.

Panera Bread (PNRA)
Offering refreshing alternatives to artery-clogging burgers and fries, Panera continues to spice things up in the fast-casual restaurant space. The company has built its reputation on its fresh products, healthy menu offerings, and compassion for its customers and community. Unlike competitors that have focused on pricing promotions, Panera has managed to command higher prices as it enhances its menu. The company boasts no long-term debt on its svelte balance sheet and enjoys robust cash flow, allowing Panera to expand into new markets. Panera possesses massive global growth opportunities, as less than 1% of Panera's restaurants are currently located outside the U.S.

Over the past three years, Panera's revenue has averaged annual growth of 16%, and earnings have averaged 24%. The company's P/E ratio is around 27, which is in line with its five-year average P/E ratio. Meanwhile, the industry average P/E is close to 29. Panera's forward-looking P/E is less than 22.

Cummins (CMI -0.25%)
This Indiana-based company manufactures engines, power systems, and related technologies such as filtration, fuel systems, and emission solutions. Cummins is one of the world's largest manufacturers of diesel engines. The trucking fleet in the U.S. is historically old and in need of replacement. A pickup in demand for trucks will likely drive growth for Cummins. Also, the continued push for stricter regulations globally should drive sales of components to meet emissions and fuel-efficiency standards.

Over the past three years, Cummins' revenue has averaged annual growth of 8%, and earnings have averaged 12%. The company's recent P/E ratio has been around 18, while the industry average P/E is close to 20. Cummins' forward-looking P/E is less than 13.

Get started today
Don't let the April 15 deadline pass you by. Consider these three attractive growth stocks for your Roth IRA contribution dollars today. Make the time to fund a Roth IRA and secure your financial future today. Years from now, you'll be thankful you did.