Speaking at the DIY chain's spring season launch, Silezin said: "One of the largest risks this year is the prolonged flooding and prolonged impact on people's gardens."
Parts of the UK had the wettest January for 100 years, with 175-220mm of rain falling in the south and west.
The weather hit B&Q early in 2013, when spring quarter outdoor seasonal sales fell by 10 per cent, with bedding down eight per cent. But Silezin said bedding sales grew by the end of 2013 after a long summer boom that also brought "phenomenal growth in garden leisure" and resulted in "low-digit" overall 2013 growth.
She said she is "planning for average" and has "tweaked" around less-risky stock. This means fewer palms and box balls, more topiary and a "shift around with bedding and nursery" as well as no impatiens, which used to be top sellers before downy mildew hit in 2011.
There has been "no clear shift" to begonias or petunias from impatiens, said Silezin. She added that B&Q sources plants from Coletta & Tyson and Roundstone "for what they're good at" and buys specimens from Sicily, Pistoia and Spain.
B&Q "took responsibility for growers in 2013" as opposed to some retailers who refused ordered stock because of the cold spring.
"We clear the stock out. But the challenge was keeping quality in stores and we had to skip plants in some instances. Growers hold quality better than us. The last couple of years have been particularly challenging."
She said B&Q left no growers in financial difficulty, adding: "I'm not going to say we took 100 per cent but we managed grower by grower, week by week, and prioritised critical crops like bedding over nursery stock. Our priorities were UK growers and some import lines were not brought out."
B&Q is running a Royal British Legion poppy promotion in 2014 and has new gas barbecues "benchmarked against Weber" products.
Silezin said new B&Q brands Blooma and Verve were "slow burners to build as brands" but the chain is sticking with them because "it's been tough to measure after two poor weather years". Customers found store home delivery more important than buying online, she added. B&Q will avoid the "distractions" of celebrity endorsement and the RHS Chelsea Flower Show in 2014.
Bedding buyer Ben Smith said B&Q is trialling houseplant and nursery online delivery over two days but bedding is difficult because of wastage caused by transport problems. He cited the Canny Gardener, which recently went into administration, and used the same bedding supplier (Roundstone) as B&Q as an example.