If I had to pick the best ASX dividend stock to buy in March, Telstra Group Ltd (ASX: TLS) would be high on my list.

After its February results, I think the investment case for income-focused investors looks stronger than it has in years.

Here’s why.

A growing dividend

Telstra declared an interim dividend of 10.5 cents per share, which was up 10% on the prior period. Importantly, the dividend was 90.5% franked, with 9.5 cents franked and 1 cent unfranked.

If we annualise that interim dividend, we get 21 cents per share for the full year.

At a share price of $5.18, that implies a forward dividend yield of approximately 4.1%.

And with around 90% franking, the grossed-up yield for Australian investors on lower…