The Big Allotment Challenge began with over 2 million viewers on Tuesday, according to overnight ratings.
BBC Two's latest competition was seen by 2.5m (11.8%) at 8pm, down 200,000 from last week's The Great British Sewing Bee finale in the same slot.
The channel's Great British Menu cooked up 1.8m (9.1%) at 7.30pm, while new documentary series Watermen: A Dirty Business interested 2.2m (10.2%) at 9pm. Jools Holland's Later... Live returned with 805k (4.7%) at 10pm.
On BBC One, Shetland ended its current series with 4.1m (19.3%) at 9pm. Have I Got a Bit More News For You amused 2.1m (17.6%) at 10.35pm.
ITV's River Monsters appealed to 1.8m (9.3%) at 7.30pm (157k/0.7% on +1). A repeat of Midsomer Murders gathered 2.1m (10.2%) at 8pm (261k/1.4%).
On Channel 4, Embarrassing Bodies returned with 1.3m (6.1%) at 8pm (242k/1.1%). New Worlds climbed slightly to 488k (2.4%) at 9pm, while a Dogging Tales repeat intrigued 491k (3.6%) at 10pm (130k/1.8%).
Channel 5's Nightmare Neighbour Next Door appealed to 1.5m (7.3%) at 8pm (191k/0.9%), followed by The Mentalist with 934k (4.3%) at 9pm (152k/1.0%). Law & Order: SVU thrilled 665k (4.2%) at 10pm.
On BBC Three, The Call Centre rose by around 400k to 1.2m (5.4%) at 9pm, followed by Sweat the Small Stuff with 439k (2.5%) at 10pm. Family Guy tickled 896k (11.1%) at 11pm.
