Peanuts and sunflower hearts: which, how, and when

Peanuts and sunflower hearts are the two foods most people end up buying again and again. They suit different feeders and carry different risks, so this guide puts them side by side. The wider comparison of every food type is in bird foods compared, and the general question of what to put out is in what to feed garden birds.

The sources, opened on 14 November 2026, are the BTO feeding page, the RSPB’s bird feeding page, the RSPB’s bird café page and the RSPB’s latest feeding guidance, dated 30 October 2026. No feeder maker’s page was opened, so no product, size or price is given here.

Sunflower hearts

Sunflower hearts are sunflower seeds with the husk already off. The RSPB describes them as husk-free and rich in oil and protein, and says they are popular with lots of birds. Its café page pairs them with a hanging plastic feeder and names finches, tits and sparrows.

The BTO says hearts cost more than black sunflower seed, and gives two advantages. Birds can feed more quickly because they do not have to remove the husk, and there is no pile of husks left on the ground after they have eaten. That second point matters more than it sounds. A heap of husks under a feeder is untidy, and it hides the spilled food you should be clearing up.

Hearts go in an ordinary seed tube. They are not small enough to need a fine-port feeder; that is nyjer, which has its own guide.

Peanuts

The RSPB says a variety of birds like peanuts, which give protein and fat in the colder months. The café page pairs a hanging mesh peanut feeder with tits and nuthatches.

The feeder is the important part. The RSPB says nut feeders made of rigid steel mesh are “the only safe method of offering nuts to wild birds”. The BTO says peanuts are best supplied behind a wire mesh “so that a bird cannot take a whole peanut away”.

Loose whole peanuts

The RSPB’s café page lists “loose peanuts” among the things not to put out, and says to keep peanuts in a suitable feeder so small chunks can be nibbled. Put together with the BTO’s line about whole peanuts, the message from both organisations is the same: do not scatter whole peanuts on a table or the ground. Use a rigid mesh feeder so birds take pieces, not the whole nut. Neither page we opened gives a detailed explanation, so we are not adding one.

Peanut quality and aflatoxin

The BTO says peanuts can be contaminated with a naturally occurring toxin called aflatoxin. It advises buying good-quality peanuts from a reputable source and avoiding any that show signs of mould. The RSPB’s café page says poor-quality peanuts can carry the aflatoxin fungus, “which kills birds if they eat it”.

So the practical rules are simple. Buy from a seller who sells peanuts for wild birds, not the cheapest sack you can find. Look at them before you fill the feeder. Throw away anything damp, discoloured or mouldy.

Choosing between them

There is no single winner, and we have no feeding trial of our own to offer. What the pages describe is a split:

• Sunflower hearts suit a tube feeder and a wide range of seed-eating birds, with less mess.
• Peanuts suit a rigid steel mesh feeder, and tits and nuthatches.

The RSPB adds one more point in its October 2026 guidance: finches prefer seeds, but when seeds are not available they will turn to peanuts. Many gardens put out one feeder of each, a little apart, rather than choosing.

The seasonal rule covers both

Both foods fall under the same seasonal advice. The RSPB’s October 2026 guidance says that from 1 November to 30 April you can feed a full range of foods, including seeds and peanuts. From 1 May to 31 October it says to pause filling feeders with seeds or peanuts, because there is a higher risk of disease spreading in summer and autumn. The BTO’s page gives the same split, November to April, and says it introduced that seasonal advice in April 2026.

Sunflower hearts are a seed, so they come under that rule too. If you want to keep feeding through the summer, the RSPB says small amounts of mealworms, fat balls or suet can carry on; see fat balls and suet.

Small amounts and clean feeders

The RSPB says seeds and peanuts should all be eaten within one to two days. Fill feeders with what the birds will clear in that time, not to the brim. Empty and refill rather than topping up on top of stale food.

Cleaning follows the routine in cleaning bird feeders. The RSPB says bird feeder hygiene needs to be done weekly, and that you should also clear old food and droppings from beneath feeders. Mesh peanut feeders trap dust and broken nut in the corners, so give the mesh a proper scrub, not just a rinse, and let it dry before refilling.

Spilled hearts and peanut crumbs under a feeder are also what bring rats. The RSPB’s October guidance says uneaten food can attract rodents; see rats and bird feeders.

Storing them

The BTO says to keep peanuts cool and dry and to buy them in small quantities. That fits sunflower hearts as well: they are oily and go stale. A sealed, rodent-proof bin in a cool place is what the RSPB café page asks for. Details are in storing bird food.

Can I put whole peanuts on the bird table?

No. The RSPB lists loose peanuts among the things to avoid, and says rigid steel mesh feeders are the only safe way to offer nuts. The RSPB’s current advice is also against flat surfaces such as bird tables.

Are sunflower hearts worth the extra cost over black sunflower seed?

The BTO says hearts cost more but birds feed faster and no husks are left on the ground. Whether that is worth it is your call; we give no prices.

Can I feed peanuts in summer?

The RSPB and BTO both say to pause seeds and peanuts from May to the end of October. The RSPB says small amounts of fat balls, suet or mealworms can continue.