April 20 and 21 marks Nationwide Open House weekend -- the unofficial opening day of the spring real estate season. Since curb appeal strongly influences home values, its a great weekend to spruce up your own yard, especially if the neighbors are trying to sell their home.

How much value can neighborhood curb appeal add? Having nice landscaping adds 1,777 in home value when youre selling your home, according to data collected in a HomeGain.com survey about how home improvements boost home value.

Curb appeal works in the other direction, too. If a for-sale house down the block is sporting some bad curb appeal, it could sell for less than it might otherwise. And that comparable sale drives down the value of your home.

We couldnt find any data on how much the average buyer discounts his offer when the neighbors havent painted their house since 1979, but we do know nobody pays top dollar to buy next door to a house that looks like the before picture in a siding ad.

Here are 6 quick exterior projects you can do in a day or two to add to your homes value and neighborhood appeal.

• Landscape for curb appeal by re-sodding bare spots, trimming shrubs, and adding colorful spring flowers to your front yard.

• Add some outdoor lighting for curb appeal to highlight your beautified yard after dark.

• Pitch in with the neighbors to rent a power washer for a day to give your sidewalks and deck a little care and maintenance. Be gentle and careful if you decide to use the power washer to clean your homes exterior; you can easily blast things off your house, like the paint, or get water into siding seams.

• Clean your siding, whether its brick, wood, or vinyl, by using a long-handled, soft-bristled brush, soap (trisodium phosphate), and water.

• Create a little cool curb appeal with house numbers -- that is, dress up your address.

• Freshen up the look of winter-ravished patio furniture with new pillows, a bright umbrella, or a colorful tablecloth to give the impression to anyone at the open house that the neighbors have fun parties.

Are your neighbors yards boosting or detracting from home values on your block?

Dona DeZube has been writing about real estate for more than two decades. She lives in a suburban Baltimore Midcentury modest home on a 3-acre lot shared with possums, raccoons, foxes, a herd of deer and her blue-tick hound.