The fertilizer recommendations contained in this response are specific to Colorado and may or may not apply to your area.

One possibility is that neighbor has either a different grass species, or if it's the same species (Kentucky bluegrass is the most commonly used grass species for Colorado lawns), then your neighbor may have different varieties or cultivars. For example, Midnight Kentucky bluegrass is very green, while other varieties are less so to various degrees. With 200-plus cultivars/varieties of Kentucky bluegrass available, you can see why there could be some variation. This is a somewhat academic point, because most lawns in Colorado are sodded and Kentucky bluegrass sod growers use three to 10 different cultivars/varieties of Kentucky bluegrass seed, resulting in an "average" green.

You might check the fertilizer analysis on your bag. The first number (nitrogen) should be much higher than the others. It may be that your organic fertilizer product has relatively low nitrogen. You could apply a "quick greenup" application of urea (46-0-0) at 1.5-2 pounds of urea per 1000 sq ft. Apply it by mid-May and do not apply more than 2 pounds urea/1000 square feet. If you cannot find urea, substitute a 28-3-3 at 3.5 pounds/1000 square feet. Iron applications can help green up a lawn as well. Make sure your core aerator pulls 2-inch plugs and makes enough passes so that core holes average 3 inches apart or closer. Lime application is rarely needed for Colorado soils as most already have high to excessive lime (calcium compounds). For more information, go to: Home Lawn Care.