In Northern California, winter is the rainy season, the time when the ground is the softest. By June, the ground is already back to cement. Is there a down side to core aeration in late winter (Feb. Mar.)?
Coring is beneficial at almost any time. The only real concern is the stress in the heat of the summer, and opening the ground at that time so soil dries out easier. Even summer coring is done in areas where grass is grown in pure clay soils.<br>Aesthetics can be a concern. With fall coring, to most people the season is over and the cores are not even noticed. Fall rains in our area erase cores usually in 3 weeks. If we spring core, we generally powerrake after the cores are dry, because with spring, people are noticing the landscape more in anticipation of better things to come.<br>Would winter coring in your situation be unattractive for a long time? That would by a concern. Also, are you dealing with a heavy soil that will be re-compacted by the time grass is growing again in spring? If this is the case then wait til very late winter.<p>----------<br>Jim<br>South Bend, IN