Question
I have been leveling my lawn the past 4 years with huge quantities of top soil (125 yards approx). I'm at the point now where just small areas need to be adjusted. Varying opinions have been raised with using "sharp mason's sand" as an ingredient in leveling low spots in a "clay" soil. Some say sand will mix with the clay and promote a worse situation for lawn irrigation, and others say the sand will open up the soil for better irrigation. Which is correct?

Answer
Work sharp, grit sand into the soil as it will not only improve the drainage characteristics of the soil, but will also improve the aeration of the soil, render it easier to work, and encourage strong root formation by your lawn.

Choose a sharp or gritty sand, not a building or a soft sand, which contain too many 'fines' and clay particles.

Your local Construction supply company will most likely stock a grit sand, sometimes called a 'concreting' sand (not concrete), in 80 lbs bags that can be carried in a car, and in two ton bulk loads that can be delivered to your home by the suppliers delivery truck. Garden Centres also stock 'horticultural sands' in 40 or 80 lbs bags, although they are often more expensive than products found from Construction companies.

You can also open up your soil by adding organic matter (compost). The problem with this is that you need to continue to improve soil or you will end back up at the begining once the compost has decomposed sufficiently. Amending with ground large particle sand as above is your best option.