Top Ground Gear Force (once referred to as Top Garden Ground Gear Force) was a one-off TV special, featuring the cast of BBC's Top Gear, which originally aired on BBC Two at 22:00GMT on 14 March 2008 as part of Sport Relief 2008. It was repeated on Easter Monday, 2008. It borrowed its format from Top Gear of the Pops, a similar one-off special which aired as part of Comic Relief 2007. Whereas Top Gear of The Pops combined Top Gear with Top of the Pops, this episode combines the motoring show with Ground Force, a gardening make-over show which ran on the BBC from 1998-2005.
Regular Top Gear hosts Jeremy Clarkson, James May and Richard Hammond take over sportsman Sir Steve Redgrave's garden, to dispense advice on creating a zero-maintenance lawn, installing an impressive water-feature and getting rid of unwanted plants. Naturally, disaster ensues.
As the team's only 'country bumpkin', Hammond is the team leader. However, his garden plan fails to impress Clarkson and May, who want to include a water feature and a shed, respectively. They are sent to a Wyevale Garden Centre to pick up supplies, returning with their desired equipment.
Hammond uses a small digger to dig a trench, to be used to create a 'river of gravel.' Clarkson earlier revealed his unique method for pulling up weeds and cutting branches off trees using a shotgun. Hammond's digger topples over in the trench, so he returns with a much larger digger to pull it out, resulting in leaving numerous caterpillar track marks all over the garden lawn. Meanwhile, James and the Poles have completed the shed, but Clarkson accidentally shoots a hole in it, breaking a window.
Hammond's tree seat is completed, however it's completed outside the tree trunk. He brings in a 14 ton crane to hook the seat so he could slip it over the tree. The crane is too heavy and sinks into the lawn, leaving huge holes in it. However the crane is long enough to hook onto the seat. However, because of Richard's inexperience with cranes, he accidentally swishes the seat sideways, destroying both the shed and the seat.
Clarkson decides to remove a rockery by using a homemade bomb. During the explosion one wall of the shed James has rebuilt, after it was destroyed by Hammond, is smashed by the blast. After this happens May steps out of the shed with a plank of wood, and asks what time the programme will air. After being informed it was going to air after the watershed, he exclaims 'you're a fu-'. At this point, the episode cuts to the next scene.
Jeremy orders some cement to pave over the garden, but he orders too little, and only a small portion of the garden is covered. Hammond gets stuck in the cement, and Jeremy lifts him out. James' shed is rebuilt for the third time while Jeremy erects some rugby posts (despite being told that none of Sir Stephen Redgrave's family plays rugby). However, he and the Poles accidentally drop the posts on James' shed, squashing the roof and part of the walls. This leads to James angrily telling Clarkson to apologise while pointing a two-by-four at him. Hammond reveals his barbecue system, which uses a jet engine to rotate the meat and cook it. However, the blades rotate too fast and flings the chickens off the roticary and the fire from the engine sets James' newly-rebuilt (for the fourth time) shed on fire.
The team then received word that Sir Steve Redgrave was coming up the drive to the house. Redgrave is upset at the destruction of his garden, so the Poles run away. Eventually he comes around thanks to Jeremy talking to him privately. Jeremy then shows off his turbo-charged water feature, which blows the top off itself due to the water pressure and crashes into the greenhouse built by the Poles, breaking all the glass. Until then, the greenhouse was the only structure still intact (and the only item in the garden Steve Redgrave was pleased with).