Dear Martha: When should I use a blender, and when is a food processor better?

A: In general, a blender is for tackling liquids and a food processor is the go-to gadget for solid foods.

Given the processor's different attachments - the S-curve blade is the basic one - the appliance can slice and grate vegetables, cut butter into pastry dough and chop nuts. It's great for whipping up hummus and pesto, and the shallow bowl makes scooping easy.

Although you can puree with a food processor, the blade cuts through the mixture instead of blending it, so the result sometimes falls short of the desired silky texture.

When you want a smooth consistency, use a blender. Its short, angled blades and multiple speeds make it suitable for pureeing a soup, mixing a smoothie or even crushing ice (if you have a high-powered model). Plus, the tall jar can hold a greater volume than most processors.

A handheld immersion, or stick, blender is another option. Because it's inserted directly into a pot, an immersion blender is ideal for large batches.

Sometimes, either appliance might work well, depending on the purpose. Consider homemade baby food: You might first use a blender to make an easy-to-swallow vegetable puree. Then, when the child is ready for chunkier foods, switch to a food processor.

Dear Martha: How do I divide my irises, and when is a good time to do so?

A: For irises to flourish, they need to be divided into smaller plants when clumps become crowded and flowering declines, usually every three to four years.

The type of irises you have will determine how and when to divide. The four most common are reticulated iris, which flowers in early spring; Dutch iris, in mid- to late spring; bearded iris, in late spring to early summer; and Siberian iris, in early summer.

Reticulated and Dutch irises grow from bulbs, whereas bearded and Siberian irises grow from rhizomes (thick underground stems).

To divide bulbous irises, wait until the foliage and flowers have withered completely; this will give the plant a chance to gather energy. It's best to divide Siberian and bearded irises immediately after they have flowered, so that the plants will have the maximum amount of time to recover before winter.

Choose a cool, cloudy day to divide. Lift the entire clump with a sturdy border fork, and inspect it carefully, discarding any withered, corky or dry parts. For bulbous irises, gently pull apart the individual bulbs and replant them about 3 inches below the soil's surface. For bearded and Siberian irises, rhizomes should be cut into pieces with a sharp knife, making sure each has a growing poinrhizot or foliage "fan." Replant the rhizomes at soil level, and do not apply mulch, as it encourages rot.

If you end up with more irises than you need for your garden, give the extras to friends and neighbors. Be sure to include instructions for proper planting, and avoid leaving bulbs or rhizomes out of soil for more than a day or two; they might not revive if left to dry out.

Dear Martha: I've relocated my flower bed and now need to remove a long strip of grass that's about 2 feet by 50 yards. What's the best way to do this?

A: You can rent a sod cutter, a machine that goes under the roots of the grass and lifts it up like sod. Then you can replant it or give it away. Or turn it upside down and add it to your compost pile.

If you don't want to rent a machine, the other option is to dig underneath the grass with a flat spade. But that will take a long time.

I suggest using a sod cutter. It's definitely worth it.

Questions should be addressed to Ask Martha, care of Letters Department, Martha Stewart Living, 601 West 26th Street, 9th floor, New York, N.Y. 10001. Questions may also be sent by e-mail to: mslletters@marthastewart.com. Please include your name, address and daytime telephone number.