Will it come true from seed? Store-bought nuts, grafted fruit, cultivars, and the seedlings they make

A nut or seed from a wild native tree grows into the same species, differing from its parent in details such as nut size, growth and hardiness. A named variety does not come true. Named apples, English walnuts, pecans and Japanese maples are mostly grafted, each a copy of one chosen tree. Their seeds carry genes from two parents and grow into new trees. A raw walnut or pecan bought to eat can still grow, but a roasted one cannot. An acorn from a yard oak may be a cross between two oaks.

What true to type means

A seedling is true to type when it matches its parent. Seed combines the genes of two parents, so every seedling differs from both. Black walnuts grown from different parent trees differ widely in nut size, kernel, ease of cracking, cold resistance and growth. Each seedling of a wild black walnut is still a black walnut.

Named varieties, cultivars, are copied by grafting, budding or cuttings, and each copy is genetically identical to the original tree. Copying is the only way to keep some cultivars, and most fruit and nut trees are budded or grafted.

An apple sets fruit only with pollen from a different variety, so every seed in it is a cross of two varieties. A seedling rootstock, the root a named apple is grafted onto, is grown from apple seed, and nobody can say what each seed will be:

“Although you won’t know exactly what you’re getting with a seedling rootstock—every single seed is a genetically different individual —hardiness, anchorage and adaptability to different soil types are generally excellent.” (University of Minnesota Extension, Growing apples in the home garden)

The Autumn Blaze maple is a Freeman maple, a cross of red and silver maple, so its seedlings are a new mix of two species. Japanese maple cultivars range from green and gold leaves to red and purple ones, and most are grafted. Fall color is partly inherited too, so a seedling may not match its parent’s fall color.

Will a nut from the store grow?

Walnuts grown for sale are dried in gas dryers to 8 percent moisture, but walnuts survive drying. A raw one in its shell can sprout after 90 to 120 days of cold, damp storage. Pecans bought in November grow the same way after at least two months in the refrigerator. A roasted nut has been cooked, and a cooked nut will not grow. Chestnuts and acorns die if they dry out.

English walnuts are planted as grafted trees, and ‘Chandler’ is the variety most planted for the nut trade. A store walnut therefore grows into an English walnut of no named variety. A pecan from a southern variety may not ripen its nuts in a northern season.

What comes up from the nuts people plant

A sound black walnut sprouts the spring after it falls, sometimes a year later, and most wild ones start from nuts that squirrels bury and forget.

We grow every plant in the table except the English walnut.

Chestnut species cross readily, so a nut from a tree near another kind of chestnut may be a hybrid. The American Chestnut Foundation says so even of the wild-type American chestnut, a tree never crossed on purpose:

“These are sometimes referred to as “pure” American chestnuts but it’s important to remember that all nine species of chestnut worldwide […] can hybridize with each other in the wild and some wild trees may be natural hybrids.” (The American Chestnut Foundation, FAQs)

A tree you can predict

Seed from a wild native tree gives a tree whose kind you know, and a batch of seedlings keeps the variation that helps a species adapt. Blue Whale Trees grows every tree it sells from seed, not grafted, so each seedling is genetically distinct. We grow no orchard apples, Freeman maples or Japanese maples. Our acorns, nuts and seed come from the same proven parent trees as our saplings, under acorns, nuts and seed. The seed sowing planner gives the dates to chill and sow each species we grow, maples among them. Planting acorns, nuts and seed covers collecting, storing and the first year.

Common questions

Can you grow a walnut tree from a store-bought walnut?

Yes, if it is raw and in its shell, since walnuts survive the drying they get before sale. Keep it cold and damp for 90 to 120 days, and expect an English walnut of no named variety.

Do apple seeds grow true?

No, because an apple sets fruit only with pollen from another variety, so each seed is a cross that grows into a new kind of apple. Named apples are sold as grafted trees.

Can you grow a tree from a chestnut?

Yes, if the chestnut never dried out, since drying kills it. Keep it cool and damp until you sow it an inch deep, and a Chinese chestnut seedling bears in four to seven years.

How long does it take for an acorn to grow into a tree?

A northern red oak acorn sprouts the spring after it falls, and the tree first bears acorns at 20 to 25 years. Heavy crops wait until 40 or 50.

Sources

• 13. Propagation: NC State Extension, Extension Gardener Handbook: seed combining the genetic material of two parents into offspring different from each, the genetic variation that helps a species adapt, cuttings, budding and grafting giving copies genetically identical to the parent, copying as the only way to keep some cultivars, and most fruit and nut trees budded or grafted.
• Growing apples in the home garden: University of Minnesota Extension: apples needing pollen from a different variety, a grafted apple as two genetically different individuals, seedling rootstocks grown from apple seed, and the quotation on every seed being a different individual.
• Acer x freemanii (Freeman maple): NC State Extension Gardener Plant Toolbox, with its Acer palmatum page: Freeman maple as a hybrid of red and silver maple with Autumn Blaze among its cultivars, and Japanese maple cultivars with green, gold, red or purple leaves, most of them grafted.
• Black Walnut: USDA Forest Service, Silvics of North America: seed weight, kernel, crackability, cold resistance and growth varying widely among black walnut families, black walnut and butternut never crossing in the wild, some nuts at 4 to 6 years and large crops at 20 to 30, seedlings coming up from nuts that squirrels bury and fail to recover, the spring after or a year later, and 36 inches of growth in a seedling’s first year on rich soil.
• Northern Red Oak: USDA Forest Service, Silvics of North America: acorns germinating the spring after they fall, and northern red oak hybridizing readily with other red oaks.
• Juglans L., walnut: USDA Forest Service, Woody Plant Seed Manual, Agriculture Handbook 727 (F.T. Bonner, 2008): walnuts surviving drying, stratification for 90 to 120 days, and English walnut’s seed-bearing age of 8 years.
• Walnut: UC Marin Master Gardeners, University of California Agriculture and Natural Resources: English walnuts planted as grafted trees, ‘Chandler’ as the most widely planted commercial cultivar, and walnuts dried in gas dryers to 8 percent moisture.
• FAQs: The American Chestnut Foundation: wild-type American chestnuts never crossed on purpose, and the quotation on natural hybrids among the chestnut species.
• Production and Marketing of Chestnuts in the Southeastern United States: University of Florida IFAS Extension: Chinese chestnut seedlings variable in nut size, taste, tree form and productivity, and the chestnut species hybridizing readily.
• From a Nut to a Tree: Grow Your Own Pecan Seedlings: Oklahoma 4-H, Oklahoma State University: pecans bought or collected in November, at least two months in the refrigerator before sprouting, and cooked pecans that will not grow.