Green spots on potatoes contain bitter toxin

Dear Martha: Why are potatoes sometimes green? Are they OK to eat?

Answer: When potatoes are exposed to light they can make chlorophyll, which turns them green. A bitter compound known as solanine, which can be toxic if eaten in quantity, forms during this process. Avoid eating potato skin or flesh that has a green tint: Cut off green portions or peel until only white flesh is exposed.

To prevent the greening process, store unwashed potatoes in a cool, dark, well ventilated place for up to two months for baking varieties; new potatoes keep for a week. Temperatures of 70 degrees Fahrenheit and above can cause potatoes to shrivel or sprout. Sprouting is also associated with increased amounts of solanine, so always remove any growths before eating.

Do not refrigerate potatoes: At temperatures of less than 40 degrees F, the vegetable's starches can turn to sugar, resulting in an overly sweet taste and excessive browning during cooking. And consider purchasing individual potatoes instead of a bulk bag. This way you can handpick the best specimens.

Dear Martha: What is a window well?

Answer: A window well is a cutaway in the soil around a basement window that lets light in and serves as an emergency exit. U.S. building codes demand "egress" or a safe exit when a bedroom is located below ground. A window well or bulkhead (a sloping exterior door) satisfies the requirement.

In the former case, most building codes call for one window that is 5.7 square feet or larger and no more than 44 inches off the floor, so a person could boost himself up and out. Unless the lot slants, there often isn't room between the ground and the top of a foundation for a window that complies with these regulations. That's where window wells come in.

To make one, the soil outside must be cut back around the window, creating a landing that is at least 3 feet by 3 feet. There also needs to be a reinforcing system, such as a metal or wooden wall, to hold the soil in place. And if the outside landing is more than 44 inches below ground, there must be a ladder or steps. Check your local building codes for additional requirements.

Some window wells have grates over the top to prevent people — especially kids — from tumbling in and to provide extra protection against intruders. You may also install bubblelike covers, which keep water from draining onto the landing and then seeping into the basement. Grates or covers must be designed to be opened easily from the inside.

Dear Martha: What are the benefits of time-release fertilizer? If I use it, will I need to apply other kinds?