How quickly is miracle grow absorbed. Due to neglect, my containered cherry tomatoes were greatly in need of water and fertilizer. I gave them the proper dosage, and 12 hours later we had a heavy rain come through.
A stump grinder uses a spinning blade fitted with carbide tipped teeth that scrape away at the stump. Bear in mind that a stump grinder can only work to a limited depth, normally up to 10-12 inches. If you feel up to it, stump grinders can be hired by the day at most local hire shops. If you decide to use a contractor to do the work for you, expect to pay a minimum of around Â£65 plus VAT for the smallest of stumps.
As to the size of the grinder for a rental I would seek the largest I could find, a 252 tackling 100 stumps like pictured looks like more than a one day job to me. As for sinking later on, be sure to grind the stumps out completely and this will be avoided.