Buyer's Guide
Choosing Bird Seed
The cheapest bag on the shelf is almost never the cheapest bag to feed. Here is how to tell the difference before you get to the register.
The short answer
- Judge seed by cost per usable calorie, not price per pound. A mix that is half filler delivers roughly half its weight in food, which doubles the true cost.
- The ingredients worth paying for are black oil sunflower, sunflower hearts, white proso millet, safflower, nyjer, peanuts and a little cracked corn.
- Milo (sorghum), wheat, oats and red millet are the four fillers that give a cheap mix its weight and end up on the ground.
- Read the ingredient list, which runs in descending order by weight. If sunflower is not first or second, put the bag back.
- Bulk buying only pays if you can keep the seed cool, dry and sealed. Sunflower oil goes rancid and pantry moths hatch in warm storage.
The number that matters when you buy bird seed is cost per usable calorie, not price per pound. A bargain mix that is half milo and cracked wheat delivers roughly half its weight in food that your birds will actually swallow. The rest gets flicked onto the ground within a day.
That single idea reframes the whole seed aisle. The cheap bag is frequently the expensive one, and a bag that costs half again as much per pound can work out cheaper to feed, week after week.
This page covers how to read an ingredient panel, which seeds earn their place and which are ballast, how to do the cost-per-calorie math in your head at the shelf, and when buying a large sack saves money rather than feeding pantry moths.
We do not test seed, rank brands or take affiliate money, so you will not find a product name anywhere on this page. What you get instead is the set of criteria to judge any bag in front of you, including the one from a store nobody has ever written about.
Cost per usable calorie, and how to estimate it#
Here is the arithmetic, simplified enough to do while holding a shopping basket.
Take the percentage of the bag that consists of seed your birds will eat. In a typical supermarket mix that is often 40 to 55 percent, with the balance made up of milo, wheat and red millet. Divide the shelf price by that fraction and you have the real price of the food.
A mix that is half filler therefore costs about twice its sticker price to feed. A bag of straight black oil sunflower at, say, one and a half times the per-pound price of that mix is already the cheaper option, and it has not yet been credited for the second effect.
The second effect is energy density. Sunflower is largely oil, so a pound of sunflower kernels carries roughly twice the calories of a pound of a cereal grain like wheat or milo. Birds are buying calories, not volume. A feeder filled with cereal empties fast and does very little.
The two-question test
Before any bag goes in the cart: what fraction of this is food my birds eat, and how fat-dense is that fraction? Almost every seed decision you will ever make falls out of those two answers.
How to read a bird seed label#
Ingredients are listed in descending order by weight, exactly as on human food. That ordering is the most useful thing on the bag, and it takes three seconds to check.
- Sunflower first or second. If milo, wheat or "grain products" leads the list, the bag is mostly filler regardless of what the front of the package shows.
- Named seeds, not categories. "White proso millet" is a specific ingredient. "Assorted grain products", "cereal by-products" or "seed hulls" are not, and hulls listed as an ingredient mean you are buying trash by weight.
- Percentages if given. Better bags state composition by percent. Anything unwilling to print numbers is usually hiding the ratio.
- No dye. Colored seed is a marketing decision aimed at you. Birds do not care, and the cheerful red pellets are almost always milo.
A photograph of a cardinal on the front tells you nothing about whether a cardinal would eat the contents. The full breakdown of how mixes are assembled is in reading a bird seed label.
The seeds worth paying for#
| Seed | Who eats it | Worth buying because |
|---|---|---|
| Black oil sunflower | Nearly every feeder species | Thin shell, high oil content, the closest thing to a universal food |
| Sunflower hearts | Same list, plus small-billed birds | No shell waste at all, so the cheapest per usable calorie despite the price |
| Safflower | Cardinals, chickadees, titmice, finches | Grackles, starlings and most squirrels dislike it |
| White proso millet | Juncos, doves, sparrows, towhees, buntings | The one small grain ground feeders genuinely want |
| Nyjer | Goldfinches, siskins, redpolls | Nothing else pulls finches in as reliably |
| Peanuts | Woodpeckers, jays, chickadees, titmice, nuthatches | Very high fat; buy shelled pieces for feeders |
| Cracked corn | Doves, jays, sparrows, quail | Cheap and useful on the ground, but spoils fastest of anything here |
Striped sunflower belongs in a footnote: the shell is thicker, which excludes house sparrows and some smaller birds, and that is either the point or a problem depending on your yard.
The fillers, and why they are worse than free#
Four ingredients do the heavy lifting in cheap mixes, and none of them are eaten by the birds most people are trying to attract.
Milo, sold as sorghum, is the classic. It is a round reddish grain, cheap by the ton, and in most of the country it is refused by everything except a few ground feeders and, in the Southwest, quail and some doves. Wheat goes the same way. Whole or rolled oats are a cheap bulking agent that turns to paste when wet. Red millet looks like white proso millet and is largely ignored, which is precisely why it is in there.
The cost is not just the wasted weight. Rejected seed piles up under the feeder, where it soaks up rain and turns into the mold problem described in moldy, clumped or wet seed, and then draws in rodents. You pay once for the filler and again for the mess.
Filler on the ground is a disease vector
A wet mat of rejected seed under a feeder grows mold and holds bacteria, and it is one of the routes by which outbreaks like salmonella move through a flock. If seed is accumulating faster than it is eaten, change the seed rather than raking more often.
Whole seed, hulled seed and no-mess blends#
Hulled seed costs substantially more per pound and is often the better value anyway, because you are not paying for shell. Roughly a third to a half of the weight of whole sunflower is hull, and none of it is food.
The tradeoff is spoilage. Without the shell, sunflower hearts absorb moisture within hours of rain and go sour fast. Buy them in smaller quantities, keep them dry, and put out only what gets eaten in a couple of days. The full comparison sits in no-mess and hull-free blends.
If you have a deck, a patio, or neighbors with strong opinions about your lawn, hull-free is the answer to seed mess and dead grass that actually works.
When bulk buying pays#
Large sacks are typically 20 to 50 pounds (9 to 23 kg) and carry a real discount per pound. The break-even is not about money, it is about time.
| Your situation | Buy | Reasoning |
|---|---|---|
| One feeder, mild climate | Small bags, monthly | Seed turnover is slow; spoilage eats the discount |
| Two or three feeders, cold winter | Large sack in fall | Cold dry storage is forgiving and traffic is high |
| Summer in a humid region | Smallest practical bag | Heat plus humidity is the worst case for oil seeds and moth eggs |
| Sunflower hearts or peanuts | Small, always | No shell means no protection; these spoil first |
The working rule: buy what you will feed in about six weeks in summer, and up to about three months in cold, dry weather. If a sack would sit longer than that, the discount is theoretical.
Storing seed so the savings survive#
Seed has three enemies in storage, and one container solves all three.
Use a sealed metal container with a tight lid, kept somewhere cool, dark and dry. Metal matters because mice chew through plastic bins with no trouble at all, and a chewed bin in a garage is how a rodent problem starts. Never store seed in the original paper sack.
Pantry moths arrive as eggs already in the seed rather than flying in. Freezing a new bag for 48 hours kills them, which is worth doing before you tip a large sack into your storage can. Details and the rest of the method are in storing bird seed.
Smell test every refill. Fresh sunflower smells faintly nutty. Rancid seed smells of old oil or fresh paint, and birds will walk away from a full feeder rather than eat it.
Buy for the feeders you own, not the birds you hope for
Nyjer only works in a nyjer feeder, peanuts need mesh, and millet is wasted anywhere but a ground or platform feeder. Matching seed to hardware before you buy prevents most of the waste people blame on the birds.
A seed-buying checklist#
Run this in the store and you will not buy a bad bag again.
- Flip the bag over and read the ingredient list. Sunflower first or second, or put it back.
- Scan for milo, sorghum, wheat, oats, red millet and "grain products". Any of them near the top of the list means filler.
- Estimate the usable fraction and divide the price by it. Compare that number, not the shelf price, across bags.
- Check the seed itself through the window if there is one: it should look plump and clean, not dusty, and there should be no webbing or fine powder at the bottom.
- Buy a size you will use within six weeks in warm weather, three months in cold.
- Match it to the feeders you actually own, and look up which birds eat which seed before buying anything unfamiliar.
If you are starting from nothing, skip the mixes entirely and buy one bag of black oil sunflower, which is the reasoning behind the beginner setup. Add a second seed only once the first feeder is emptying in about a week.
Frequently asked questions#
What is the best bird seed to buy?
Straight black oil sunflower seed is the best single purchase for most North American yards. It appeals to more feeder species than any other seed, has a thin shell that small birds can crack, and contains no filler you are paying to sweep up. Add other seeds only once you know which birds visit you.
Is expensive bird seed worth it?
Often yes, because price per pound is a poor guide. A premium mix with no milo or wheat can cost noticeably more per pound and still be cheaper per calorie your birds actually eat. What is rarely worth paying for is a mix with dried fruit, nuts in the shell or novelty additions that are mostly there to justify the price.
What ingredients should not be in a bird seed mix?
Milo (also sold as sorghum), wheat, whole or rolled oats, red millet, flax and generic cereal by-products. Most feeder songbirds will not eat them, so they get raked out of the feeder and rot on the ground. Dyed seed and shell fragments listed as ingredients are also a sign of a low quality bag.
How long does bird seed last before it goes bad?
Sealed, cool and dry, most seed keeps six to twelve months, and sunflower hearts noticeably less because the protective shell is gone. In summer heat or damp storage, assume four to six weeks. Rancid seed smells like old paint or oil rather than faintly nutty, and birds will avoid it long before you notice.
Is it cheaper to buy bird seed in bulk?
Per pound, yes, and the discount on a large sack is usually substantial. It only pays if you can store the seed properly and use it within a few months. A big sack that molds, attracts pantry moths or feeds a mouse population costs far more than the small bag you should have bought.