Do All Nuts Grow Underground?

Not all nuts grow underground—in fact, most common nuts like almonds, walnuts, and cashews grow on trees above ground. The few exceptions that develop beneath the soil, such as peanuts, often lead to confusion. Let's clear up the misconception and give you a practical rundown of which nuts grow where, why it matters for storage, harvesting, and your next grocery run.

Do any nuts actually grow underground?

Yes, but only a handful. Peanuts are the most well-known nut that grows underground, but they are technically legumes, not true nuts. In botanical terms, a true nut is a dry fruit with a hard shell that does not split open to release a seed. Examples include acorns, hazelnuts, and chestnuts. Peanuts develop above ground as flowers, then the stem bends downward and pushes the fertilized ovary into the soil, where the pod matures. This process is called geocarpy.

Other underground-growing "nuts" include tiger nuts (actually tubers) and earthnuts (a type of legume). But these are not true nuts either. So if we stick to strict botanical definitions, no true nut grows entirely underground. The answer to the question "Do all nuts grow underground?" is no, and almost none do.

Which nuts are commonly mistaken for growing underground?

Many people assume nuts like almonds, cashews, and pistachios come from underground because they often think of "nuts" as small, hard seeds. Let's break down the most common mistakes:

• Peanuts – As mentioned, they grow underground through geocarpy. In supermarkets, peanuts are labeled as nuts, but botanically they are legumes.
• Almonds – They grow on trees. The almond fruit is a drupe with a fuzzy outer hull and a hard shell containing the seed we eat.
• Cashews – They grow at the bottom of a cashew apple, a fleshy fruit that hangs from a tree. The nut shell contains a toxic oil that must be removed by steaming.
• Pistachios – These grow in clusters on small trees. Each pistachio is a drupe with a thin shell that splits naturally as it ripens.
• Walnuts – They grow on large trees inside a green, fleshy husk that splits open when ripe.
• Hazelnuts – They grow on shrubs or small trees inside a leafy husk that partially covers the nut.

How do peanuts grow underground? A step-by-step look

To understand the one major exception, here is the full life cycle of a peanut plant:

1. Flowering – The peanut plant grows small yellow flowers above ground. After pollination, the flower's ovary starts to swell.
2. Peg formation – A stem called a "peg" grows from the base of the wilted flower and extends downward toward the soil.
3. Burial – The peg pushes the fertilized ovary into the ground, usually 1–2 inches deep. This is called peg penetration.
4. Maturation – Once underground, the ovary develops into a peanut pod containing 1–4 seeds. The plant continues to flower and form more pegs throughout the growing season.
5. Harvest – About 120–150 days after planting, the entire plant is dug up, shaken free of soil, and inverted to dry.

This process is why peanuts are called groundnuts in some regions. No other common nut uses this method.

Why do people think all nuts grow underground?

The misconception likely comes from a few sources:

• Visual similarity – Peanuts are extremely common, and people generalize from one example.
• Linguistic confusion – In many languages, the word for peanut includes "ground" (e.g., "groundnut" in British English, "Erdnuss" in German). This leads to the assumption that all nuts grow like that.
• Lack of botanical education – Most people don't study how different nut crops are cultivated. A quick look at an almond orchard or a walnut grove shows clearly that those nuts hang from trees.
• Underground storage in myths – Some stories or cartoon depictions show animals digging for nuts, reinforcing the idea that they come from underground.

How do tree nuts grow above ground? Quick overview for common nuts

Here's a simple comparison of the growth location for popular nuts:

This table should help settle the question: do all nuts grow underground? The answer remains no—true nuts are tree-borne or shrub-borne. The underground ones are not botanically nuts.

Can you grow any nut crop in your home garden?

If you're wondering about growing your own nuts, here's a practical breakdown based on where they grow:

• Peanuts – Easiest to grow in a home garden. They need warm weather, loose sandy soil, and about 4–5 months of frost-free days. In cooler climates, you can start them indoors.
• Almonds – Require a warm, dry climate (USDA zones 7–9) and a chill period in winter. They also need cross-pollination from another almond variety.
• Walnuts – Large trees that need lots of space (40–50 feet apart). They can be grown in zones 4–9 but take 5–7 years to produce.
• Hazelnuts – Compact shrubs suitable for smaller gardens in zones 4–9. They need at least two different varieties for pollination.
• Cashews and macadamias – Only suitable for tropical or subtropical regions (zones 9–11). Most home gardeners outside those zones cannot grow them.

Common mistake: Planting a walnut tree too close to a garden bed. Walnut roots release juglone, a chemical that can kill tomatoes, peppers, and other sensitive plants. Keep walnut trees at least 50 feet away from vegetable gardens.

How does knowing where nuts grow affect storage and freshness?

Where a nut grows influences its shell, moisture content, and how you should store it:

• Peanuts (underground) – They are prone to mold, especially aflatoxins, if stored in warm, humid conditions. Always keep peanuts in a cool, dry place, ideally refrigerated. Discard any that smell musty.
• Tree nuts with hard shells (walnuts, pecans, hazelnuts) – They last longer in the shell (6–12 months in a cool pantry) but can become rancid quickly once shelled. Store shelled nuts in an airtight container in the fridge or freezer.
• Thin-skinned nuts (almonds, cashews) – These go rancid faster because they have more unsaturated fats. Keep them in the refrigerator and use within a few months.

Signs of rancidity: A sharp, bitter, or paint-like smell. If nuts taste stale or off, throw them away. Rancid nuts can cause digestive upset.

Should you buy nuts in the shell or shelled? Practical tips

Based on growth and handling, here is a simple numbered list to decide:

1. Buy in-shell for nuts that need cracking – Walnuts, pecans, hazelnuts, and almonds in the shell take longer to process but stay fresh longer. They also make a fun activity for kids and parties.

2. Buy shelled for convenience – If you use nuts frequently in cooking or baking, shelled nuts save time. Just store them properly.

3. For underground-grown peanuts – Shelled or in-shell, peanuts need cool storage. In-shell peanuts are a great snack for outdoor gatherings. If you buy large bags, transfer them to an airtight container immediately.

Consider using a nutcracker set for in-shell nuts. For chopping shelled nuts, a food chopper or mini processor makes quick work.

What are the most common mistakes people make about growing and storing nuts?

• Assuming all nuts need the same soil – Peanuts need loose, sandy soil; almonds prefer deep, well-drained loam; walnuts tolerate heavier clay. Don't treat them all alike.
• Storing nuts too warm – Nuts are high in oil. At room temperature (above 70°F), they go rancid in weeks. Always refrigerate or freeze for long-term storage.
• Harvesting too early or too late – For tree nuts, harvest when the husk splits naturally. For peanuts, harvest when the leaves yellow and the pods have distinct veins on the shell. Digging too early gives you immature nuts; too late risks mold.
• Forgetting pollinator requirements – Many nut trees need two different varieties to cross-pollinate. One almond tree alone rarely produces nuts.

Do all nuts grow underground? The final takeaway

To directly answer the question do all nuts grow underground? : No. The vast majority of nuts we eat—almonds, walnuts, pecans, cashews, pistachios, hazelnuts, macadamias—grow on trees or shrubs above ground. Peanuts are the only common exception, and they are not true nuts but legumes that develop underground after the flower buries itself. Tiger nuts and earthnuts also grow underground, but they are botanically tubers, not nuts.

Understanding the growth habit of each nut helps you choose the right storage method, avoid common spoilage traps, and even decide what to plant in your own garden. Next time you see a bag of almonds, remember they started as fuzzy green fruits high in a tree—not beneath the soil.

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