DeepRoot Partners. The Silva Cell modular system holds soil for tree growth and stormwater management while supporting paved surfaces. The system holds 10 cubic feet of soil per unit, protecting tree roots from compaction and providing room for stormwater infiltration and surrounding utilities. The 48-by-24-by-16-inch fiberglass and polypropylene cells have galvanized steel supports and can be stacked up to three cells high and laterally as wide as necessary before the decking is attached. 800.458.7668. www.deeproot.com.