Bulk bird food can save money if your garden gets through it and you have somewhere dry to store it. For a new feeding setup, I would buy a small bag first and see how much the birds eat over a few weeks. Once you know that, compare the delivered price per kilogram and choose a bag you can comfortably lift.
Compare like-for-like bags
Compare the same food on the same buying terms: sunflower hearts with sunflower hearts, and one-off prices with one-off prices.
On 12 October 2026, Garden Wildlife Direct’s sunflower hearts cost the following before delivery:
| Pack | Price | Food cost per kg |
|---|---|---|
| 5kg | £9.99 | £2.00 |
| 12.55kg | £18.99 | £1.51 |
| 20kg in one sack | £29.49 | £1.47 |
| 20kg as four 5kg bags | £31.99 | £1.60 |
The 12.55kg bag costs only about 4p more per kilogram than the 20kg sack. I would choose it if the larger sack would be awkward to lift or slow to use.
At that check, the 5kg and four-pack options were out of stock. Smaller paper-bag sunflower hearts were available at £7.99 for 2kg and £12.49 for 5kg. Compare the delivered price with sunflower hearts on Amazon before ordering.
Put delivery into the calculation
Divide the checkout total by the bag’s weight. For example, £30 delivered for 20kg works out at £1.50 per kilogram.
Paying a delivery charge can be cheaper than adding things you do not need to reach a free-delivery threshold.
Allow for waste and the feeding season
If you buy 20kg for £29.49 and discard 5kg, the food you actually use costs £1.97 per kilogram before delivery. Damp or stale leftovers can wipe out much of the saving.
At 500g a week, 20kg lasts 40 weeks; at 2kg a week, it lasts ten. Use your garden’s consumption to work out the right bag size, without increasing portions to finish a sack.
Seeds and peanuts are for November–April under current RSPB guidance. Our winter food guide explains the timing; buy enough for the feeding season you have left.
Choose storage before the sack
Choose a bird-food storage bin that holds your usual bag with room to close the lid and use a scoop. The storage containers at Garden Wildlife Direct include the Garland 30 L and 47 L storage bins, designed for up to 12.5kg and 20kg of feed respectively. Both take up 37 × 28cm of floor space; allow extra height above the larger bin to open it. These plastic bins need a dry, rodent-free storage position.
Keep the food’s label and best-before date. Empty, clean and dry the bin between batches, and check for damp or signs of chewing.
Four sealed 5kg bags cost £2.50 more than one 20kg sack in the comparison above. I would pay that for easier lifting and keeping most of the food unopened.
Buy what you can use, lift and keep dry. A clean feeder and regular spillage control will help make that food last.
