Juglans ailantifolia var. cordiformis
treeHeartnut (Juglans ailantifolia var. cordiformis) is a variety of the Japanese walnut grown for its charming heart-shaped nuts, which hang in long strings of a dozen or more and crack open cleanly into two neat halves. It is a handsome, fast-growing, broad-canopied walnut with large tropical-looking leaves, more resistant to canker than butternut and quicker to bear - often in 4 to 6 years. Like all walnuts it produces juglone, so it needs the same careful siting away from sensitive garden plants.
Sun
full sun
Water
Every 14 days
Harvest
~5 yrs
to first harvest
Difficulty
medium
Lifecycle
perennial
Comes back every year
Spacing
40-50 ft apart
Planting Depth
Bare-root in a deep hole; flare at soil line
Soil pH
6.0-7.0
Soil Type
Deep, rich, well-drained
Hardiness Zones
Zones 5 – 8
When to Fertilize
Spring only, as growth begins
Fertilizer
Balanced or compost; nitrogen per soil test
Grow heartnut in full sun in deep, rich, well-drained soil with room to spread its wide canopy. Plant a dormant bare-root or young tree in spring, water through establishment, and keep the area beneath clear. It is wind-pollinated and only partly self-fruitful, so a second heartnut or Japanese walnut nearby improves the crop. Prune lightly in late summer or fall, never in spring when walnuts bleed sap. It is vigorous and relatively trouble-free, but watch for the same husk and canker issues as its butternut cousin.
Direct sow
Apr 29
Projected first harvest
Oct 26 · Year 6
Year 1
Good neighbors that attract beneficial insects or deter pests
Proactive ways to stop trouble before it starts — tap a name with an arrow for its full guide
Maggots tunnel the husks and stain the shells; rake up and destroy fallen nuts and hulls promptly
Bores into nuts as it does apples; sanitation and pheromone traps reduce numbers
Cause honeydew and sooty mold but rarely real harm; a hose rinse and beneficial insects keep them in check
Heartnuts ripen in fall and fall in their husks; gather them promptly and wear gloves against staining. Remove the husks, wash the nuts, and cure them in an airy, shaded spot for a couple of weeks. The great virtue of the heartnut is the crack: a sharp tap on the seam splits the nut into two clean heart-shaped halves, far easier than butternut or black walnut. Cured in-shell nuts keep for months.
Heartnuts give a sweet, mild kernel much like butternut but milder, eaten fresh, in baking, and as a novelty for their perfect heart shape, and they are high in healthy fats. The tree is ornamental in its own right with bold foliage and dangling nut strings. Mind the juglone - keep tomatoes, peppers, potatoes, blueberries, azaleas, and rhododendrons clear of the root zone.
For educational and informational purposes only — HomeSown is not medical, health, or other professional advice. Always positively identify any plant before handling or eating it; some plants, and some parts of otherwise-edible plants, are toxic. Consult a qualified professional before consuming or otherwise using any plant, especially if you are pregnant, nursing, taking medication, or have a health condition.
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Year 6