How Do I Plant a Cherry Pit? The Rules of Thumb, and Where They Break

Clean the flesh off a pit taken from fresh ripe fruit, keep it damp from that moment forward, and hold it in moist cold storage for 90 to 140 days at 41°F before sowing it about an inch deep in well-drained soil. Those figures come from Penn State Extension's publication Growing Fruit Plants from Seed, whose Table 1 gives cherry an effective range of 33 to 50°F and an optimum of 41°F. Plain refrigerator stratification of that length produced 44.51 percent germination in mazzard cherry seed in a 2006 trial at Süleyman Demirel University in Isparta, Turkey. The seedling will be a genetic hybrid of two parents, will not repeat the fruit it came from, and will take longer to bear than any grafted nursery tree.

Almost every cherry-pit failure traces back to the cold period rather than to the seed. The pit is durable and usually viable. What fails is the condition it was held in, which makes this a preparation problem with measurable specifications.

The procedure, from fruit to seedling

1. Take pits from fresh, fully ripe fruit. Heat and freezing destroy the embryo, so canned, frozen, dried, and maraschino cherries yield nothing.
2. Wash the flesh off within a day or two and keep the pits damp afterward. Penn State allows brief air-drying before storage; prolonged drying kills viability.
3. Hold the pits cool through autumn in a loosely covered jar, then start cold moist storage in mid-January, the timing Penn State specifies for a spring sowing.
4. Mix the pits with damp peat, sand, or perlite, or wrap them in a damp paper towel, and seal them in a bag with a few air holes.
5. Refrigerate at 41°F for 90 to 140 days. Check every week, rewet the medium, and remove anything that molds.
6. Sow as soon as the cold period ends, an inch deep in a well-drained mix, several pits per pot. Stratified seed does not keep.
7. Grow the seedling on two seasons. If fruit is the goal, Penn State advises budding cherries onto the seedling in July or August of the second year.

An outdoor alternative skips the refrigerator. Sow cleaned pits an inch or two deep in autumn, screen the bed against rodents, and let winter deliver the chilling. The USDA Natural Resources Conservation Service Plant Guide for black cherry warns that deliberate direct seeding "has generally been unsuccessful" for restoration plantings.

Where the ten-week rule breaks

The most repeated figure in home-gardening advice is ten to twelve weeks in the fridge. That is 70 to 84 days, and it sits below the bottom of every extension range published for cherry.

Penn State Extension puts cherry at 90 to 140 days, and the gap has been measured. M. Çetinbaş and F. Koyuncu of the Department of Horticulture at the University of Süleyman Demirel stratified wild sweet cherry seed at 4°C, about 39°F, for 80, 100, and 120 days, then germinated it at 21°C in darkness. Their paper states the result plainly: "The increase of the stratification duration from 80 d to 120 d resulted in an increase in germination percentage." At 120 days, untreated seed with the stone intact reached 44.51 percent; seed whose endocarp had been removed by hand after chilling reached 56.90 percent.

That twelve-point difference is the second thing the rules of thumb miss. The hard shell is not inert packaging. Çetinbaş and Koyuncu cite Jensen and Eriksen's finding that embryo, endosperm, testa, and endocarp all contribute to holding germination back. Cracking a stone risks damaging the seed, but the difference explains why a batch given identical treatment germinates unevenly.

The temperature window is narrower than "the refrigerator"

Penn State's effective range for cherry runs from 33 to 50°F, with 41°F named as best. A refrigerator door swings across most of that band every time it opens, and a crisper drawer set for lettuce often runs warmer.

Two failure modes sit at the edges. Below freezing, chilling accumulation stops. Above roughly 50°F, warm spells can undo progress already made, which is why the cold period should be continuous rather than assembled from intervals.

Sources also disagree about whether cold alone is the right protocol. Barbara Bujarska-Borkowska and Paweł Chmielarz of the Institute of Dendrology at the Polish Academy of Sciences in Kórnik tested mazzard seed stored frozen for 15 or 20 years, then ran it through alternating warm and cold phases rather than a single chill. Their 25/3/25/3°C sequence, two weeks warm, two cold, two warm, fourteen cold, produced a mean of 98 percent germination in the 15-year seed. In the 20-year seed the same warm-start sequence gave 78 percent germination and 72 percent emergence, against 63 and 60 percent for a colder-start sequence. That protocol totals twenty weeks, landing at the top of Penn State's 140-day range while adding warm intervals Penn State's table does not describe.

Neither is wrong. Penn State writes for a gardener with a refrigerator and one winter; Kórnik writes for a seed bank with controlled chambers. The longer end of the published range is the safer bet at home.

What germination rate to expect, and how many pits to start

A realistic home expectation is about 45 percent, the Süleyman Demirel figure for stratified seed with the stone intact, rising toward 57 percent when the stone comes off after chilling. Nothing in the published record supports the folk claim that cherry pits rarely sprout.

What they do instead is sprout unevenly. W. E. Finch-Savage, H. A. Clay, and K. C. Dent, then at Horticulture Research International in Wellesbourne, titled their 2002 study in Seed Science and Technology directly: seed maturity affects the uniformity of cherry seed response to dormancy-breaking treatments. Pits from fruit at different ripeness respond to identical chilling on different schedules, and fruit picked slightly early yields pits whose embryos never finished developing.

The wild version is more extreme. The NRCS Plant Guide for black cherry records that "seeds from one crop germinate over a period of 3 years," banking seed in the forest floor against a bad season. A gardener who empties a pot after eight weeks is discarding seed operating on that schedule.

Start more pits than you want trees. A dozen is not excessive for two or three seedlings.

Seed-grown cherry versus a grafted named tree

This is the comparison the popular method leaves out. Penn State Extension states the genetics without softening: "the seeds will produce plants that will be a hybrid of two plants. The new plant will be the same kind of plant, but its fruit and vegetative portions may not look or taste the same as the parent."

Robert Andersen and Terence Robinson of the Department of Horticultural Sciences at Cornell University's New York State Agricultural Experiment Station in Geneva, writing in the New York Fruit Quarterly, describe what a grafted tree does on standard rootstock: "With Mazzard, the young trees usually start to crop more gradually with very light crops in year three, and progressively adding somewhat larger crops in year four and year five and reaching a full cropping potential about in year six or seven." Andersen is a professor at the Geneva station and leads Cornell's stone fruit breeding program. Of the newer dwarfing stocks the same authors write that they are "much more precocious than Mazzard, usually bearing a crop in the second year."

Those clocks start when a grafted nursery tree goes in the ground. A seedling starts earlier and finishes later, because it must first grow through a juvenile phase during which it cannot flower. The only firm seedling figure in this literature is for another species. Black cherry produces seed on trees "as young as 10 years," the NRCS Plant Guide records.

| | Seedling from a pit | Grafted tree on Mazzard | Grafted tree on Gisela 5 | |---|---|---|---| | Genetics | Hybrid of two parents; fruit unpredictable (Penn State Extension) | The named cultivar, identical to its parent tree | The named cultivar, identical to its parent tree | | First light crop | Not documented for sweet cherry; black cherry seedlings set seed from year 10 (USDA NRCS) | Year three (Andersen and Robinson) | Year two (Andersen and Robinson) | | Full cropping | Unrecorded | Year six or seven | Earlier, with a tendency to over-crop | | Mature size | 30 to 40 ft under cultivation, 70 ft or more in natural form (Oregon State University) | Full size; the reference against which other stocks are measured (WSU Tree Fruit) | About half the size of a tree on Mazzard (WSU Tree Fruit) | | Pollination | S-alleles inherited at random; compatibility unknown until it flowers | Known S-genotype, listed in published compatibility tables | Known S-genotype | | Best use | Rootstock, hedgerow, shade, a long experiment | A standard home tree where space allows | Small gardens, with support and crop-load management |

Mature height is itself contested. Oregon State University's Landscape Plants database records that Prunus avium "under cultivation it may reach a height of 30-40 ft (9-12 m), if allowed to grow in a natural conical shape to 70 ft (21 m) or more." The NC State Extension Gardener Plant Toolbox gives the same species 15 to 30 feet with a matching spread. The lower figure describes a pruned orchard tree; the higher one describes an unmanaged seedling. Utah State University Extension closes the escape route: "Dwarfing rootstocks are not currently available for cherries."

Chill hours decide whether the tree ever fruits

A seedling can survive for decades and still never crop, because flowering depends on accumulated winter cold that the site may not supply.

Mississippi State University Extension gives the standard accounting method: "One model defines a chill hour as each hour below 45°F starting on October 1." The requirement for sweet cherry is where sources part company. Oregon State University states that "for the termination of bud rest and normal growth in spring, sweet cherries have a chilling requirement of between 700 to 800 hours or about 28-32 days continuously exposed to 45 degrees or less." Illinois Extension publishes a far wider band for the same crop, 500 to 1,450 hours, against 600 to 1,500 for pear and sour cherry.

The spread is real rather than sloppy, since requirement varies by cultivar and different models count the same winter differently. For a grafted tree the number is knowable, because the cultivar is named. For a pit it is not, since the seedling draws its requirement from two parents, one an unidentified pollen donor.

Cold hardiness sets the other boundary. Utah State University Extension gives the damage threshold: "Sweet cherries are not very hardy, rated at zone 5 or higher, and will suffer bud and tree damage at temperatures of -10 °F or below." Tart cherries take more, with fruit-bud loss below -20 °F.

Store-bought pits, and the black cherry variation

Fresh supermarket cherries generally carry viable pits, and growing cherries from supermarket fruit works as a germination exercise. The climatic caveat stands. Much US retail sweet cherry comes from Washington and California orchards, and a seedling with that parentage inherits a chilling requirement matched to those winters rather than to a colder or milder garden.

Growing black cherry trees from seed follows different arithmetic, because Prunus serotina is a forest tree. The NRCS Plant Guide records that variety serotina "may reach 38 meters tall in the eastern US," roughly 125 feet, while southwestern varieties stay far smaller. Seed is abundant, at 3,100 to 8,100 cleaned seeds per pound in the USDA Forest Service's Silvics of North America. Anyone planting one near a house should know the NRCS guide lists a cyanogenic glycoside in its leaves, twigs, bark, and seeds.

Frequently asked questions

Can I just plant a cherry pit?

Not straight into warm soil. A cherry pit is dormant and needs 90 to 140 days of moist cold at 41°F first, according to Penn State Extension. Sown into a spring garden without that chilling, most pits sit inert all summer, and many rot before the next winter supplies the cold.

What time of year should I plant a cherry seed?

Two windows work. Sow cleaned pits outdoors in autumn, an inch or two deep and screened against rodents, and let winter supply the chilling. Or store them cool through autumn, move them into moist refrigerator storage in mid-January as Penn State Extension advises, and sow the following spring.

Can I plant store-bought cherry pits?

Fresh supermarket cherries usually carry viable pits. Canned, frozen, dried, and maraschino cherries do not, because heat and freezing kill the embryo. The larger issue is climate. Fruit shipped from Washington or California came from trees suited to those winters, and the seedling inherits an unknown chilling requirement.

How long does it take to grow a cherry tree from a cherry pit?

Longer than any grafted tree. Cornell's Robert Andersen and Terence Robinson report that grafted sweet cherries on Mazzard rootstock give very light crops in year three and full cropping around year six or seven. A seedling must first outgrow a juvenile phase in which it cannot flower at all.

How do I germinate cherry seeds in a paper towel?

Wrap cleaned pits in a damp paper towel, seal them in a labeled bag with a few air holes, and refrigerate at 41°F for 90 to 140 days. Check weekly, rewet the towel, and discard seed that molds. Sow as soon as a white root tip appears, since those roots break easily.

Will a seed-grown cherry need another tree for pollination?

Almost certainly, if it is a sweet cherry. Iowa State University Extension states that at least two different sweet cherry varieties must be planted for fruit production, because most are self-unfruitful. A seedling inherits its S-alleles at random, so its compatibility group stays unknown until it flowers. Sour cherries are self-fruitful.