Any enhancements to a standard "row house" adds value, potentially, however, to ensure that your "investment" will produce a yield that is more than aesthetically appealing gauge it in relations to how much you'll put into it, and how much similar properties, i.e., same square footage, room count, amenities, etc., are being sold for now. Your eventual beautiful yard will make your house worth more to you in the enjoyment value, but, unless you find that one potential buyer that values the results of your green thumb, they'll tend to gauge the houses potential value based on what is happening, not necessarily on what you did with the yard. This applies to the over-remodeling phenomena of a few years ago -- you couldn't go into any house without seeing someone's interpretation of enhancement by changing kitchen cabinets and laying down a granite counter top. Tread carefully if you're looking for higher returns via a green thumb.
J. Mario Preza