Bird Food

Nyjer (Thistle) Seed

A full nyjer feeder that no goldfinch will touch is the most common complaint in backyard bird feeding, and the answer is nearly always the same: the seed is dead.

If you have a nyjer feeder full of seed that no bird has touched in a month, the seed is almost certainly dead. Nyjer's entire appeal to finches is its oil, that oil goes stale quickly, and stale nyjer looks exactly like fresh nyjer.

The seed itself is small, black, needle-shaped and imported. It is the most selective food you can put out: goldfinches, siskins, redpolls and house finches take it, and essentially nothing else does, including squirrels, grackles and starlings.

Below: what nyjer actually is and why it is not thistle, how the sterilization requirement works, the freshness test that takes thirty seconds, which feeders keep it usable, and what you are really paying per calorie once you account for what falls on the ground.

Nyjer is not thistle#

Nyjer is the seed of Guizotia abyssinica, sometimes called the African yellow daisy, grown mainly in Ethiopia, India and Myanmar. It has no botanical relationship to the thistles that colonize North American pastures.

The "thistle seed" label stuck because goldfinches eat both native thistle seed and nyjer, and because the black needle shape looks the part. The name has caused decades of unnecessary worry among gardeners convinced they are seeding a weed problem into their own lawn.

The seeds are tiny, roughly 1/8 inch (3 mm) long, glossy black when fresh and dull gray-black when old. That color difference is the first thing to look at in a bag.

Why every bag is sterilized#

Nyjer imported into the United States must be heat-treated before sale. The reason is not the nyjer itself but what can travel with it: seeds of noxious weeds mixed in during harvest and handling. Heating the shipment kills any viable seed, nyjer included.

Two consequences follow, one good and one bad.

The good one: nyjer will not sprout under your feeder, so you can hang one over a lawn or a border without seeding it. The bad one: heat treatment starts the clock on oil degradation before the bag has even reached the country. A shipment that was sterilized, warehoused through a warm summer and then trucked to a store has already lost some of its appeal.

The thirty-second freshness test#

You cannot judge nyjer by looking at it in a feeder from ten feet away, but you can judge it in your hand.

• Pinch a dozen seeds between finger and thumb and rub hard. Fresh nyjer leaves a faint oily film and a slightly sweet, nutty smell. Old nyjer crumbles dry and dusty and smells faintly sour, or of nothing at all.
• Look at the sheen. Fresh seed is glossy black. Gray, matte or chalky seed is old.
• Cut one open with a thumbnail. The kernel should be pale and firm, not shrunken and hollow. A high proportion of hollow seeds means either an old batch or a poorly cleaned one.
• Check the bag for dust. A heavy layer of black powder at the bottom means the seed has been handled and knocked about, and dust clogs feeder ports.

Why a full feeder can be an empty one#

Here is the diagnostic sequence for a nyjer feeder that birds have stopped using. Work down the list, because the causes are ordered by how often they turn out to be the answer.

That last row matters more with finches than with most birds. Nyjer feeders concentrate house finches at close quarters, which is exactly the setting in which house finch eye disease spreads. If you see a bird with swollen, crusted eyes, take the feeder down and clean it properly before rehanging.

The birds that come, and the ones that never will#

The list is short, which is the point.

• American goldfinch, the species most people buy nyjer for.
• Pine siskin, in irruption winters, often in large restless flocks.
• Common redpoll, in the northern tier and in irruption years.
• House finch and purple finch, which take nyjer readily but prefer sunflower when both are out.
• Lesser goldfinch in the Southwest and California.

Juncos, doves and sparrows work the ground beneath for spill. Beyond that, nyjer draws almost nobody. If your goal is a busier yard overall, black oil sunflower does far more work per dollar. Nyjer is a specialist purchase for a specialist result, and the wider tactics live in how to attract goldfinches.

Feeders that keep nyjer usable#

Standard sunflower ports are three to four times too wide for nyjer, so the seed pours out on the ground. A dedicated nyjer feeder is a separate purchase, not an optional upgrade.

Mesh tubes are the best general choice. Birds cling anywhere on the surface, several feed at once, and air circulates through the seed, which slows spoilage. Look for metal mesh rather than plastic.

Port tubes with 1/8 inch (3 mm) openings work well and keep rain out better than mesh, but the seed column sits still and can go stale in the middle if the feeder is oversized.

Fabric socks are cheap and finches like them, but they hold water like a sponge and need replacing every season or two. In a wet climate they are the fastest route to moldy seed.

Whichever you use, size it to about a week of traffic. A big feeder that takes a month to empty guarantees that the last two weeks of seed are stale.

What it costs, counting the ground#

Nyjer is among the most expensive common bird foods per pound, several times the price of black oil sunflower. The cost per calorie a bird actually eats is worse still, for a reason people miss: finches shell nyjer at the port and drop the empty husks, so the black debris under the feeder is not wasted seed, but a real fraction of the whole seed does get knocked loose and never eaten.

Two ways to narrow the gap. First, hang a tray under the feeder to catch the drop, which juncos and doves will clear. Second, consider whether finely broken sunflower chips would serve the same birds. Goldfinches take chips readily, at a fraction of the price per pound, and many yards get most of their finch traffic from a chip feeder with nyjer as a supplement rather than the reverse.

The rest of the black mess below the feeder is husk, and it will not sprout, but it still needs raking out before it mats down. See seed mess, hulls and dead grass.

A nyjer setup that works#

• A metal mesh tube holding roughly one week of seed for your yard.
• Hung 10 to 12 feet (3 to 3.5 m) from a shrub or small tree, so finches have a staging perch and a retreat.
• Filled with seed bought a month at a time, checked by the pinch test before it goes in.
• Emptied and washed every two weeks, dried fully before refilling.
• With a catch tray below it, cleared weekly.

Set up that way, nyjer earns its price during the months when goldfinches are in bright plumage and feeding hard. Set up any other way, it is the seed most likely to sit untouched while you wonder what you did wrong.