Best bird seed: the one bag to buy, and the five times to buy something else

The short answer

• Buy black oil sunflower in shell. Of the 34 species in our preference dataset, 25 eat it readily or rate it a top food, which is broader coverage than any other single seed.
• Price per bag pound is the wrong number. Compare cost per pound actually eaten, which means dividing the shelf price by the edible fraction: black oil at 75% kernel works out near $1.80 a pound eaten against $2.60 for hulled hearts.
• The five exceptions are a deck or patio (buy hearts), grackles and starlings (buy safflower), a house sparrow problem (buy striped), goldfinches only (buy nyjer), and a ground-feeding crowd (add millet).
• A single seed in each feeder beats a mix in nearly every case. Mixes are priced on their cheap filler and cost you twice: once for grain you paid for, once for the mess it makes on the ground.
• Buy no more seed than you will use in about six weeks. Sunflower is a high-oil seed and goes rancid, and the birds notice before you do.

Buy black oil sunflower seed, in the shell, in the largest bag you will get through in about six weeks. That is the answer for most yards in North America, and the rest of this page is the argument for it plus the five situations where it is wrong.

The reason the answer is so stable is that two separate questions happen to have the same answer. Which seed do the most birds want? And which seed delivers the most food per dollar once you stop counting the part they throw away? Black oil wins both, and it is unusual for a food to win both.

The coverage argument#

Our preference dataset scores 34 North American feeder species against 13 foods on a 0 to 4 scale, where 4 is a top-tier favorite and 0 means the bird will not take it at a feeder. Counting across that grid:

• Black oil sunflower is rated 3 or 4 by 25 of the 34 species. The nine that are not include two hummingbirds, an oriole, a robin and a bluebird, which are not seed birds at all.
• Sunflower hearts score marginally broader still, 28 species at 3 or more, because the hull is the only thing keeping some birds off sunflower.
• Striped sunflower manages 11. Safflower manages 8. Nyjer manages 6.

That is the whole shape of the seed aisle in four numbers. Sunflower, in one form or another, is the general-purpose food. Everything else is a specialist, and specialists are bought to solve problems, not to fill a feeder.

Top top-tier favorite Yes eats readily Some takes occasionally Rare rarely No not a feeder food

Read the black oil column down that subset and you will see why one bag works: the cardinal, the chickadee, the nuthatch and the house finch all rate it top-tier, and the goldfinch, jay and junco all take it readily. The full grid is on our bird food preference chart.

Why the shelf price is the wrong number#

A seed in the shell is sold by total weight, and you cannot eat the shell. The number that matters is cost per pound eaten, which is the shelf price divided by the edible fraction.

Prices are 2026 United States big-bag benchmarks used as defaults in our seed cost calculator. Swap in your own and the ranking can change; the edible fraction and energy columns will not.

Work through the sunflowers with our benchmark figures and the ranking rearranges itself:

Two things fall out of that table that people get wrong in both directions.

The first: hearts are dearer than in-shell seed and subtracting the hull does not rescue them. On the shelf the gap is nearly double; per pound eaten it is still about 44%. Buy hearts for what the hull does to your yard, not in the belief that they pay for themselves. Run your own numbers through the seed cost calculator if your local prices differ, because they will.

The second: striped sunflower is not a cheap seed. It sits close to black oil on the shelf, but its hull is thicker and heavier, so two fifths of the bag is packaging. Per pound of kernel it costs about 48% more than black oil, which lands it alongside hearts, a seed with no hull at all.

Calories sharpen it further, because kernels are not equally rich. Sunflower kernel runs around 51% fat; safflower kernel is nearer 38%. So safflower loses twice, once on yield and once on density. Per calorie delivered it costs roughly 88% more than black oil. That is the honest price of the pest filter you are buying, and it is worth paying in some yards and absurd in others.

Buy this if you buy one thing#

Black oil sunflower in shell, in a feeder the birds can actually use.

It is the default because it is the only seed that is simultaneously the top food for small-billed birds and acceptable to almost everything larger. The thin hull is the mechanism: a chickadee weighing 11 g can wedge one in a bark crevice and hammer it open in seconds, which it cannot reliably do with a striped seed. The detail of that hull, and how to judge a bag of it, is on the black oil sunflower page.

If you want a rule for quantity: one 20 lb bag will run a single well-used feeder from roughly late November into January in a northern suburb. Buy that, not the 50 lb sack, unless you have somewhere cool and dry to keep it. See storing birdseed.

The five exceptions#

1. The seed goes over a deck, patio or balcony#

Hulls are the problem, not the seed. About a quarter of a black oil bag ends up as shell, and on decking it stains, on a balcony it blows into the neighbor's furniture, and on a lawn it kills the grass under the feeder. Switch to sunflower hearts, accept that they cost about 44% more per pound eaten, and fill in small amounts because hearts spoil fast when wet. On a balcony, keep the fills small enough to clear in two days.

2. Grackles, starlings or blackbirds are emptying the feeder#

This is the safflower case. In our dataset the common grackle and the European starling both score 0 on safflower, and the red-winged blackbird scores 1, while the northern cardinal scores 4 and chickadees, titmice, nuthatches and house finches all score 3. No other seed separates the two groups that cleanly. Expect two to three weeks of birds ignoring it, and read safflower seed before you switch the whole station over, because the transition takes longer than people expect.

3. House sparrows are swamping everything#

Safflower helps here too, but the sharper tool is striped sunflower. Its hull is thick enough that a house sparrow drops from a top-tier rating on hearts to an occasional rating on striped, while blue jays, evening grosbeaks and cardinals rate it at the top. You are trading breadth for selection: striped loses you goldfinches, siskins and juncos almost entirely.

4. You only want goldfinches#

Then buy nyjer and a feeder with slit ports. Goldfinches, siskins and redpolls rate nyjer top-tier and almost nothing else does, which is precisely the point. It is the most expensive common seed per calorie, and it is still the right purchase if a flock of goldfinches is the goal.

5. Juncos, doves and native sparrows are what you have#

Ground-feeding birds want small round seed, not sunflower. Add white proso millet on a low tray, not in the tube. After cracked corn, millet is the cheapest genuinely useful seed per pound eaten in the dataset, and it is much better food than corn. The caution is that house sparrows also rate it top-tier, so if you already have a sparrow flock, millet feeds it. In the West and Southwest, where quail and towhees use the ground layer, cracked corn earns a place too.

Single seed or a mix#

Fill each feeder with one seed. This is the single highest-leverage habit in feeding birds, and it saves money in a way that is invisible until you do it.

A mix is priced against its cheapest ingredient. When a bag is 40% milo, wheat and oats, you paid for that 40% and the birds will not eat it in most of North America. Worse, they do not ignore it politely: a chickadee sweeps unwanted seed sideways out of the port to reach the sunflower, so the filler ends up on the ground, where it draws rodents and grows mold. You pay for the grain, then you pay again in raking, rodents and a dead patch of lawn.

The arithmetic is brutal. If a mix is $1.10 a pound and only half of it gets eaten, the eaten fraction cost $2.20 a pound before you count hull. Straight black oil at $1.35 a pound with a 75% kernel yield costs $1.80 a pound eaten, and every one of those pounds is food a bird wanted.

There are two honest exceptions:

• A sunflower-only or sunflower-and-peanut blend, which is really just two good seeds in one bag and is a reasonable convenience purchase.
• A deliberate two-food station, sunflower up in the feeder and millet down on a tray. That is not a mix, it is two feeders with different customers, and it is the setup most experienced feeders end up with.

The longer version of this argument, with the label-reading rules, is in birdseed mixes and seed mix versus single seed.

The order to add foods#

If black oil is bag one, this is the sequence that adds the most new species per dollar:

1. Black oil sunflower in a tube or hopper. Covers the perching guild.
2. Suet in a cage. Adds downy, hairy and red-bellied woodpeckers, plus flickers, wrens and creepers that sunflower alone will not bring. Ten of the 34 species in our dataset rate suet top-tier.
3. White proso millet on a ground tray. Adds juncos, white-throated sparrows and doves.
4. Nyjer in a slit-port feeder, if goldfinches have not already come to the sunflower.
5. Safflower or striped, only when a specific pest is costing you seed.

Most yards are finished at step three. Steps four and five are bought to solve a named problem, not to round out a collection.

Buying and keeping it#

Two rules, both about oil.

Buy for six weeks, not for the season. Sunflower and safflower kernels are high in unsaturated fat, which oxidises. Rancid seed does not look different, but birds reject it, and a feeder that suddenly goes quiet in mild weather with no hawk around is often a stale-seed problem.

Judge the bag before it goes in the feeder. Grab a handful. It should feel dry, smell faintly nutty and leave almost no dust on your palm. Fine gray powder in the bottom of the bag means crushed seed and old stock. Webbing or small pale larvae means moth infestation, which spreads to every bag in the shed. Clumped seed means it got wet at some point and is on its way to mold.

Store it in a metal bin with a tight lid, off a concrete floor, somewhere cool. Freezing a suspect bag for 48 hours kills insect eggs and buys you the rest of the season.

Frequently asked questions#

What is the single best bird seed?

Black oil sunflower in the shell. Nothing else comes close on breadth: cardinals, chickadees, titmice, nuthatches, finches, grosbeaks, jays, woodpeckers, juncos and sparrows all take it, and its thin hull means an 11 g chickadee can open it as easily as an 85 g jay can. It is also the cheapest of the sunflowers per calorie delivered once you account for the hull you are paying for and throwing away. Start with one bag of it and add a second food only when you have a specific bird or a specific problem in mind.

Is expensive bird seed worth it?

Sometimes, and the test is cost per pound eaten rather than cost per bag pound. Hulled sunflower hearts cost roughly twice as much on the shelf as black oil in shell, and black oil is about 75% kernel by weight, so the gap narrows to about 44% and stays there. That is a premium worth paying where hull is the problem, on a deck or a patio, and not worth paying over a lawn you do not mind raking. Nyjer and mealworms are genuinely expensive per calorie and are worth it only when you want the specific birds they bring. A cheap mix full of milo is never worth it, because most of the bag is swept onto the ground uneaten.

Why do birds throw so much seed out of the feeder?

They are sorting a mix. A chickadee that wants sunflower will flick milo, wheat and oats out of the port to reach it, and a cardinal will do the same on a tray. The waste you see under the feeder is not greed, it is the filler you bought. Switch that feeder to one seed the visiting birds actually eat and the mess usually drops by more than half within a week. What remains is hull, which is unavoidable with any in-shell seed.

Should I buy a seed mix or single seeds?

Single seeds, in separate feeders. A mix forces every bird to sort, spills the rejected fraction on the ground, and hides how much of the bag is filler. Two bags, black oil sunflower and white proso millet, cover the perching birds and the ground birds better than any three-way mix, and you control the ratio by how much you put out rather than by what a blender decided. The exception is a good all-sunflower or sunflower-and-peanut blend, which is not really a mix at all.

How much seed will one feeder go through?

A single tube feeder in a busy suburban yard in winter typically empties a 1 to 2 lb fill in three to five days, faster in a cold snap and much faster if grackles or starlings find it. Use that as a buying rule: multiply your weekly consumption by six and buy no more than that at once. Sunflower is high in unsaturated oil, and a bag that sits in a warm shed through summer will be rancid by autumn even if it looks fine.

Is cheap birdseed bad for birds?

Not toxic, but usually wasteful and sometimes risky. Bargain mixes are built around milo, wheat, oats and cracked corn, which most feeder birds in the East and Midwest ignore. That grain sits on the ground where it draws rodents and grows mold, and moldy corn in particular can carry fungal toxins. Buying a smaller bag of one good seed costs less per bird fed and leaves nothing rotting under the pole.

Sources and further reading

1. Feeding Birds Cornell Lab of Ornithology, Project FeederWatch Which foods attract which feeder birds, the broad appeal of black oil sunflower, and why old or damp seed should be discarded rather than topped up
2. Bird Feeding and Care National Audubon Society General seed and feeder guidance for backyard stations
3. FoodData Central US Department of Agriculture, Agricultural Research Service Fat, protein and energy composition of sunflower and safflower kernels