PopCap is set to release the much-awaited sequel to its hit tower defense game Plants vs. Zombies next year. But that doesn’t mean that the original Plants vs. Zombies is now being left to fend for itself and wither like a trampled-upon sunflower.

Just a few hours ago, PopCap planted a substantial update to both Plants vs. Zombies for iPhone and Plants vs. Zombies HD for iPad.

The update delivers full Retina display support for the third-generation iPad. That means that, at long last, you can now play Plants vs. Zombies HD in true Retina iPad HD!

Beyond that, several other enhancements that apply to both iPhone and iPad editions of the game are brought by this latest update.

Most notable among these is the new Last Stand game pack, in which “the zombies have invaded en masse and the fiends have denied you the use of Sunflowers!”

Plants vs. Zombies

In Last Stand, you have to take a stand against four levels of zombie hordes all while using only a limited amount of sun power. If you’re so steadfast as to make it through those levels, you can go ahead and take on the Last Stand’s even more challenging endless variant.

To help you stand tall against your undead adversaries, you can take advantage of the new mallet pack. And you can earn the new Hammer Time, Still Standing, and Stuff of Legends achievements in the process.

For all existing players, this garden-fresh update to Plants vs. Zombies for iOS is available for free. But for the 10 or so persons who haven’t played the game yet, the newly updated Plants vs. Zombies for iPhone and Plants vs. Zombies HD for iPad are available in the App Store for $2.99 and $6.99, respectively.

The update to the game also includes a new link to the official Plants vs. Zombies online store, where you can purchase merchandise to satiate your horticultural zombie-busting self.