The seeds of a pine cone hide deep inside it, at the inner base of the woody scales, not on the outside surface. Each cone is really a protective case built around its seeds, with each seed resting on top of a scale.1Dyck Arboretum of the Plains. Where Are the Seeds in a Pine Cone? Most cones people pick up from the ground are already open and empty, because they release their seeds while still on the tree.
Exactly Where the Seeds Sit on Each Scale
Hold a freshly fallen cone with the pointed tip facing up and you’ll find the seeds close to the stem, just above the scales.2The Center for Northern Woodlands Education. Pine Cones: The Complicated Lives of Conifer Seeds The scales are the individual woody pieces that give the cone its shape. Most pines carry two seeds on each fertile scale, side by side. A white pine seed looks a bit like a maple seed, with a papery tail running the length of the scale.3The Center for Northern Woodlands Education. Pine Cones: The Complicated Lives of Conifer Seeds When you pull a scale back, the wing is what you see first, and the seed is the small dark lump at its base.
The exposed tip of each scale is just tough, bare wood. The seeds sit in a pocket on the scale’s upper face, and the scale above covers that pocket while the cone is closed, so a seed is shielded on every side until the cone dries and the scales part.
To look for seeds, choose a cone that is still tight or only slightly open, since wide-open cones are usually emptied. Bend one middle scale outward and look at its base, right against the central stem. You’re looking for a pair of small seeds, each attached to a thin, tan, papery wing. With an open cone, tap it upside down over a white sheet to shake loose any seeds left inside.
The fertile scales sit in the middle band of the cone. Scales at the very top and bottom are often small and carry no seeds, so skip those. Check a few scales from different spots around the cone, because seeds may have dropped from some places and stayed in others.
Seeds in most common pines are small, often about the size of a grain of rice or smaller. Their dark, mottled color blends into the shaded interior, so tilting the cone toward the light helps.
A few things trip people up. Some mistake the papery wing for the seed itself. Once a seed falls out, it leaves a smooth, wing-shaped imprint on the scale, and a thin tan wing with no seed attached simply means the seed has already come off. A real seed feels hard and slightly oily or smooth, while crumbly resin, bark, or a broken scale tip feels rough or sticky.
Only Female Cones Carry Seeds
A pine grows two kinds of cone: small male cones that shed pollen, and larger female cones that develop seeds. Male cones are soft, clustered, and drop off after shedding pollen in spring. Female cones are bulkier, with tightly packed woody scales. So the hard woody cone you find on the ground is almost always a seed cone. A small, soft, brown, crumbly cone is probably a spent pollen cone with nothing inside.
On the tree, male cones are finger-tip sized, papery, often yellow or reddish, and gathered in clusters at branch tips. Seed cones are larger and woody, and sit singly or in small groups. A yellow dust cloud lifting from a branch in spring comes from the male cones. Young seed cones may stay green and tightly closed for a year or more before ripening.
Pollen from the male cones lands on young seed cones in spring, but the seeds take a long time to ripen. That slow timeline is why one tree can carry young green cones and mature brown cones at the same time.
Why Your Pine Cone Looks Empty
Cone scales gape open when the air is dry, letting the seeds fall out, and close again when it’s damp.4Nature. How pine cones open The scales bend on their own as they soak up or lose moisture from the air, with no living action needed.5PubMed Central. The Structural and Mechanical Basis for Passive‐Hydraulic Pine Cone Actuation A cone can open and close many times, even long after it falls. An open brown cone has very likely already let go of its seeds.
Each scale has two layers that shrink by different amounts as they dry, so the scale bends outward as the cone dries out. When damp air or rain wets the scale, the layers swell back and the scale presses closed. This suits the tree, because dry air tends to be good flying weather for a seed, while rain would make it drop quickly near the parent.
You can watch this at home. Soak a cone in water and its scales close within hours. Leave it on a dry, sunny windowsill and they spread open again.
Some pines have cones sealed shut with resin until heat opens them, often after a fire. Sealed Monterey pine cones open at around 45 °C (113 °F) on average, anywhere from 35 to 53 °C.6PubMed Central. Seed release by a serotinous pine in the absence of fire: implications for invasion into temperate regions In hot climates such cones can open on hot days even without fire. Sealed cones look different from ordinary closed ones: their scales are glued together with hardened resin, and they may stay on the branch for years. They often still hold seeds, and a closed cone found on the ground may too.
Other things empty cones too. Squirrels often cut cones from the branch and strip the scales one by one, leaving a ragged core and a pile of scale pieces beneath the tree. Birds such as crossbills and woodpeckers pry seeds out, so a cone with scales torn or pried apart has probably been worked over. Some seeds stay inside but are empty or damaged, and in poor years trees set few seeds at all.
What a Pine Seed Looks Like Inside
Each seed has three main parts: the seed coat, the embryo, and a food store.7Ministry of Forests. Anatomy and Morphology of Conifer Tree Seed The seed coat protects what’s inside but can also slow how fast water and air reach the embryo.8Ministry of Forests. Anatomy and Morphology of Conifer Tree Seed The embryo holds everything needed to grow into a full tree.9Ministry of Forests. Anatomy and Morphology of Conifer Tree Seed The food store surrounds the embryo and feeds it until the seedling can use sunlight.10Ministry of Forests. Anatomy and Morphology of Conifer Tree Seed The white, oily part you eat in a pine nut is mostly this food store plus the embryo.
The hard coat keeps out fungi, insects, and drying air while the seed waits, sometimes for months. Because it can slow water uptake, a seed may sit dormant even after landing on damp soil.
Cut a large pine seed open and the embryo appears as a small pale rod in the middle of the white food store. One end becomes the root, and the other carries a ring of tiny leaves that become the first needles.
To tell whether a seed is good, cut it lengthwise. Plump white tissue filling the cavity means it’s filled; a dark, dry, or hollow cavity means it won’t grow. A float test works as a rough sorting aid, since filled seeds tend to sink while many empty ones trap air and float. It isn’t perfect, though: a floating seed may occasionally be sound and a sinking one damaged. Check a sample with the cutting method before trusting the float test for a whole batch.
How the Seeds Travel Away From the Cone
The single papery wing makes the seed spin like a helicopter as it drops.11Berkeley News. Conifers’ helicoptering seeds are result of long evolutionary experiment As it falls, the wing catches air and begins to rotate, and the spinning creates lift that slows the fall. Single-winged seeds stay in the air almost twice as long as double-winged shapes.12Berkeley News. Conifers’ helicoptering seeds are result of long evolutionary experiment Longer flight carries seeds farther, especially in gusty air.13Berkeley News. Conifers’ helicoptering seeds are result of long evolutionary experiment
In practice, most winged seeds land within a modest distance of the parent tree and only a few travel far, so a seedling right under a mature pine is common. Landing spot matters: a seed that falls on thick litter or in deep shade is less likely to grow than one reaching bare soil with light.
Some pines, such as piñon and whitebark pine, have large wingless seeds spread by birds.14The Auk. Cache-site selection in Clark’s Nutcracker (Nucifraga columbiana) Clark’s nutcrackers carry pouches of piñon seeds up to 22 km and bury them 2 to 3 cm deep.15Ecological Monographs. Coadaptations of the Clark’s Nutcracker and the Pinon Pine for Efficient Seed Harvest and Dispersal Forgotten caches sprout into new trees.16Ecological Monographs. Coadaptations of the Clark’s Nutcracker and the Pinon Pine for Efficient Seed Harvest and Dispersal Shallow burial protects seeds from drying and from many seed eaters, which gives a forgotten seed a good chance.
You can see the wing at work yourself. Drop a winged seed from head height and watch it spin. Pull the wing off a second seed and drop both together: the wingless one lands first. Do it indoors or on a still day, because wind will confuse what you’re watching.
Eating and Growing Pine Seeds
Store-bought pine nuts come mostly from a few large-seeded pines such as stone pine, piñon, and Korean pine. Most backyard pines have seeds too tiny to be worth shelling, with only a thin shell around a small kernel. Some taste resinous or bitter. Even in commercial stone pine cones, a cone’s weight is mostly woody scale, with kernels around 4% or less.17Options Méditerranéennes: Série A. Séminaires Méditerranéens. Impact of the Dry Cone Syndrome on commercial kernel yield of stone pine cones
If you want to harvest nuts, identify the species first, since a few conifers that aren’t true pines, such as yew, are poisonous. Nut-bearing pines are often harvested as closed, mature cones, then dried in a warm, dry place until the scales part and the seeds can be shaken out. The seeds still have a hard shell, which a nutcracker or a light tap with a mallet opens. Gentle roasting can improve flavor.
Many pine seeds won’t sprout until they’ve had a cold, damp chill, called cold stratification.18Seed Science Research. Seed stratification and germination strategy in the Mediterranean pines Pinus brutia and P. halepensis Some Korean pine seeds need about 6 months at 1 to 5 °C.19New Forests. The temperature and length for the release of primary and induction of secondary physiological dormancy in Korean pine (Pinus koraiensis Sieb. et Zucc.) seeds Needs vary even within one species, with seeds from colder places needing longer chilling.20Seed Science Research. Seed stratification and germination strategy in the Mediterranean pines Pinus brutia and P. halepensis Ordinary backyard pines usually need only a few weeks to months.
The chill imitates winter so the seed doesn’t sprout in autumn and then freeze. Seeds need moisture during the chill, which is why they’re kept in damp material.
To try it, remove the wings and soak the seeds overnight in water. Seal them in damp paper towel or sand in a bag and keep it in the refrigerator, not the freezer. Check the bag every week or so, and discard seeds that look moldy or smell sour. Sow shallowly in spring in well-drained soil, and expect only some to sprout.