Use these step-by-step instructions to grow an acorn into an oak tree. Find out how to choose the best acorns in fall and follow the tutorial to sprout the seed, grow it into a sapling, and plant it in your garden.
See How To Grow An Apple Tree From Seed for another at-home tree-growing tutorial.
From Acorn To Oak Tree
- Collect freshly fallen, ripe acorns in fall from a local, native species.
- Acorns from white oaks can be planted immediately.
- Acorns from red oaks need a few months of cold stratification before they can germinate.
- If you don’t know which type you have, follow the fridge method (below). This is an indoor method used to mimic cold stratification.
- When choosing a site for your oak tree in your garden, allow room for the mature size of the tree and do not plant other competing trees, shrubs, or vines in its midst. These majestic trees require lots of growing space.
Beyond the sheer majesty and beauty of oak trees (genus Quercus), it’s pretty wild that something that grows from an acorn ends up providing essential food and habitat for all sorts of living things—from mammals to butterflies to microbes—for hundreds of years (or more). This continues not only throughout the life of the tree but as it is dying and decaying as well.
With numerous invertebrate and arthropod species relying on these trees, oaks are indeed what we call “natural bird feeders.” Just think of all the caterpillars one oak tree could sustain and how many birds they in turn nourish. And that’s just one of many examples.
Up top, their huge leaf canopies slow rain fall and provide much needed shelter and shade. Once fallen, those same, slow-to-decompose leaves protect numerous species on the ground.
Below the soil surface, in the root zone, carbon is sequestered and rain water is managed.
And we haven’t even mentioned the many thousand acorns produced over the life of the tree—a food source for various animals, providing fat, protein, carbohydrates, vitamins, and minerals.
While many of these traits are not unique to oaks alone, as the dominant tree in American forests with more biomass than any other tree, their contribution is truly significant.
If you have the space and choose an oak species native to your region, it’s certainly one of the best eco-beneficial plant choices you can make.
To grow one, you can buy potted, bareroot, or burlap-wrapped oaks for planting, but it’s pretty cool to instead grow your own from acorns found right in your neighborhood. Some also assert that this may be the most reliable way.
While there are hundreds of oak species in many parts of the globe, our focus is on white oaks and red oaks—the two most common groups of oaks found here in parts of Canada and the United States.
It is important to note that oak-related diseases are spreading throughout some regions, so do your homework first to make sure planting oaks is indeed recommended where you live.
And, if it is, gather your acorns and start growing.
- Getting Started
- Collecting Acorns For Germinating
- Sprouting Acorns
- Planting Sprouted Acorns
- Oak Sapling Care
- Frequently Asked Questions
Can I grow an oak tree from an acorn?
Yes, you can grow your own oak trees from acorns but there are a few things to know first.
Nature has produced oak trees from acorns for millions of years. When they grow naturally, it means the acorn is viable and the growing conditions are right—the same things we need when growing them intentionally at home. I’ve provided tips on all of this below.
“Every oak tree started out as a couple of nuts who stood their ground.”
~Henry David Thoreau
It’s also helpful to manage our expectations. Just as most plants produce far more seeds than will ever grow, oaks produce far more acorns than will ever become trees. Animals, diseases, weather, and lack of viability or suitable growing conditions all get in the way.
To beat the odds, start a bunch and hope for a few.
What is an acorn?
Biologically, acorns are the fruit of oak trees and have one or, less often, two seeds inside. They are also classified as nuts because they have hard shells.
The cap of an acorn is not part of the fruit and is not required for germination.
Should I grow an oak tree?
Despite their role as a keystone species in ecosystems, oaks are not always the best choice for home gardens.
Here are some things to consider first.
Right Plant, Right Place
The simple and direct garden advice “right plant, right place” is helpful to follow.
Done right, an oak tree will provide immense benefits to animals (including humans) and the ecosystem for many years to come.
In the wrong location, the tree may become such a hindrance that it will need to be cut back or removed entirely. These Site Considerations will help guide your decision.
There is also the issue of diseases like oak wilt and sudden oak death that are wiping out entire oak populations in some regions. These problems are so serious that your local conservation authority may not recommend planting oaks at this time but will suggest other, more suitable native species instead.
If growing oaks is encouraged, here are some tips:
- Choose an oak species native to your region and suited to your specific growing conditions.
When growing from seed, it helps not only to collect acorns from local oaks but go the extra step and identify the mother tree to be sure it is an oak species native to your area.
See the Resources section for a guide to identifying oak species.
The long-term growing location should offer the following (for large, wide-spreading oaks):
- At least 30 feet of unobstructed canopy space, free from other competing tree species or overhead wires.
In The Nature of Oaks, Doug Tallamy also encourages growing oaks in groves. Spaced around 10-feet apart, oak root systems will co-anchor one another.
- Tree stem located at least 30 feet from any nearby buildings, patios, or paved pathways to avoid root issues. You don’t want them growing into your basement walls or uprooting your sidewalk.
- A location where the underground bedrock is at least 15-feet below the soil surface allowing plenty of unobstructed space for the roots to grow downward.
What To Expect
At first, after sprouting the acorn using the directions (below), you will likely be growing your oak in a pot.
After a number of months when it reaches sapling stage, you can plant it in the ground. Because the roots are sensitive, the less often an oak is transplanted, the better.
During the early years, the space around the young oak in your garden can be used for other plantings like vegetables, flowering perennials, and annuals. Do not add any trees, shrubs, or vines that will compete for root space and eventually become over-shadowed.
After a decade or several decades, depending on the species, the oak will gradually demand more space both in and above ground.
Collecting Acorns For Germinating
Growing oaks from acorns involves collecting viable acorns, chilling and/or rooting them, planting the sprouted acorns in pots, and eventually planting the young sapling in the ground.
Collect Healthy Acorns
Fall is the time to collect acorns for sowing. If you are familiar with oaks you may have noticed that they do not produce acorns every single year.
- Many oaks produce acorns every two to three years.
- Some white oaks (Quercus alba) produce acorns every four to six years.
- Plus, some years are “mast” years where the tree produces an abundance of acorns, far greater than other years.
In a year when the oak is producing acorns, the best collection time is going to depend both on the species and your location.
- For example, here in southwestern Ontario (zone 6b), acorns become ripe and drop from the trees from late September, into October and November.
The best acorns to collect are ones that have recently fallen to the ground: acorns still on the tree may not be ripe yet (although if they come off with a bit of a shake, they may be good to use).
- Once the tree is starting to drop its acorns, ignore the early ones and wait until the bulk of them are falling. These tend to be of better quality.
- If a storm forces a bunch down, they are likely also not ripe enough to sprout.
Avoid acorns that appear diseased or damaged or have holes in the shell.
Is This Acorn Viable?
We can never know for sure if an acorn is viable, but there are clues:
- It’s fall and the time the tree would naturally drop its acorns.
- The acorns have fallen from the tree within the last day or so without added force from something like a storm.
- The acorn caps are either not attached or detach really easily. If they are stuck on tight, the acorn is not mature. There are certain species that are exceptions to this but most do let go of their caps when ripe.
- The acorn is brown or mostly brown, not green.
Watch the squirrels. They are very good at picking the best ones. Get in there or you’ll miss your chance.
Once you’ve collected your acorns, deal with them immediately. Acorns will not stay viable if they get too dry, too hot, or freeze.
White Oak Versus Red Oak – Why It Matters
There are two major groups of oaks in North America:
- White oaks (Quercus section Quercus) which produce acorns that germinate in fall. These oaks have rounded leaf lobes.
- Red oaks (Quercus section Lobatae) which produce acorns that germinate in spring after cold stratification. These oaks generally have pointier leaf lobes.
This is why it’s helpful to identify the tree your acorns came from if possible:
- If you know it’s a white oak species, the acorn is capable of germinating right away. They are so quick to sprout that you may even find acorns on the ground with roots already forming. If you do, you can plant them in pots right away (using the directions below).
- If it’s a red oak species, the acorn will need a period of cold stratification before it can germinate. This can be done with the fridge method (below) or by keeping them protected in pots (planted in potting mix) outdoors throughout the winter.
If you don’t know what you have, I still recommend following the fridge method which makes it easy to monitor for germination and keeps the acorn protected from animals.
Fun Fact | Squirrels eat white oak acorns right away and store red oak acorns for later.
It’s commonly recommended to germinate acorns in a pot or plant them directly in the ground.
I prefer the fridge method because I can monitor root growth, know exactly which acorns will succeed, and not worry about pest damage.
The Fridge Method
With the fridge method, we are storing acorns in moist paper towel in the fridge (34° to 40°F / 1° to 4°C—typical fridge temperature range) until roots grow 1 to 2 inches long.
- Fresh, mature acorns
- Paper towel (I use 6 double sheets) – single use or reusable
- Plastic food bag or container
- Sharpie marking pen
Overview | Sandwich the acorns between layers of moist paper towel and place them in a food bag or container in the fridge.
The point is to keep the acorns exposed to moisture (but not soaking wet) and cold (but never freezing) temperatures.
- Label food bag or container with date and type of oak (if known).
- Moisten six (or so) sheets of paper towel in water. If you squeeze the paper towel in a ball, it should feel moist but not drip water.
- Spread out acorns on layer of moist paper towel.
- Cover acorns with another layer of moist paper towel and place in food bag or container. Ideally, the acorns are spread out and not touching, each in full contact with the moisture. Keeping them spread out is a precaution so that, when roots form, they don’t get tangled and break.
- Place everything (acorns in moist paper towel in bag) in fridge. We suggest keeping the bag or container open to allow some air flow.
- Create a reminder in your calendar or phone to check on the acorns every few days.
- Re-moisten the paper towel as needed and watch for changes. Roots—if they are going to grow—will form from the pointy end of the acorn where the embryo is located within. This first growth is the radicle root—the taproot—which must not be handled or damaged in any way. Sometimes the stem appears first or at the same time as the roots. Either way, be happy it’s growing.
White oak acorns, if viable, sprout quickly, often within a week or a bit longer. Cold stratification (outdoors or in the fridge) is not required for these acorns to sprout.
Red oak acorns, if viable, need weeks or months of time in the fridge first before they are ready to sprout.
- When roots are 1-2 inches long, your sprouted acorn is ready for planting in a pot.
Whether you grow the potted seedling indoors or outdoors (at first) will depend entire on the timing. There is more on this below.
Planting Sprouted Acorns
These instructions are the same whether you found a sprouted acorn on the ground in fall or have germinated acorns yourself.
Once the roots are 1 to 2 inches long, the acorn is ready for planting.
Be very careful when handling the seedling—that first root, the taproot, is very sensitive and the plant may die if the root is handled or broken.
Two options: you can continue growing the sprouted acorn in a pot or plant it directly in the ground.
I recommend keeping the seedling in a pot and continue growing it until it’s around a foot tall with several leaves.
With containers, it’s easy to rig up some protection (like a wire cloche or upside-down mesh waste basket) to keep animals from digging up or eating the acorn or plant, and you can move it around as needed to provide the best growing conditions.
Because the roots don’t like being messed with, it’s ideal to plant the sapling in the ground just once where it can enjoy a long, happy life.
Planting A Sprouted Acorn In a Pot
- Sprouted acorn with roots at least 1 to 2 inches long
- Potting mix, moistened with water
- Flower pot (at least 1-foot wide and 1-foot deep) with drainage holes
Plant your sprouted acorn approximately 1/2-inch to 1-inch deep. Place it on its side with the roots aimed down toward the bottom of the pot.
- Fill flower pot with moist potting mix, leaving an inch or two from the top.
- Form a hole in the potting mix for the acorn roots and gently place sprouted acorn on its side in container with roots aimed down to bottom of pot. If your acorn has already grown a shoot, aim it upwards.
- Cover acorn with an inch (or bit less) of moist potting mix.
- Very gently press potting mix in place and add more water or moistened potting mix if needed.
Oak Sapling Care
Indoor or Outdoor Growing?
It’s best—by far—if you can grow your young oak sapling outdoors (forever more) but it all depends on the timing.
- Acorn sprouted in fall | If your acorn sprouts in fall before first frost, you can keep it potted outdoors throughout the winter. Keep it watered until freezing temperatures set in and protect it from animals with a wire cloche. Near first frost in fall, insulate the pot so the plant cannot freeze and protect it from winds that may dry it out. I find a few inches of straw mulch is sufficient here in zone 6b. Check soil and water if needed in winter. Remove straw and resume regular watering as temperatures warm in spring.
- Acorn sprouted mid-winter or early spring | The one time we may need to grow the potted acorn seedling indoors for a while is when an acorn propagated in the fridge is ready for potting mid-winter, weeks or months before last frost. In this case, the pot should go in a sunny window until last frost, ensuring the young plant is never allowed to dry out.
In spring around last frost, you will “harden” the oak, gradually getting it used to outdoor growing conditions over a week or two until it’s ready for life outdoors full-time.
Routinely check the underside of the flower pot to ensure the roots are not growing out the bottom. You want to transplant your oak to its permanent location before it gets rootbound in its pot.
It’s time to plant your oak sapling in its final, outdoor location when it is around 12-inches tall and has several leaves.
As a native tree suited to your growing conditions, the only ongoing care your young oak should need is watering until the roots are well-established or there is a drought. You’ll also want something like hardware cloth to protect the tree from gnawing animals like deer or rabbits. There are more tips on deterring deer here.
Frequently Asked Questions
What’s the best time to collect and grow acorns?
Fall is the time to collect acorns to sprout and grow into oak trees. The acorns should be freshly-fallen on the ground and their caps should be off or very easy to remove. Depending on your location in Canada or the United States and the species, collection time may be late September, October, or November.
Should I float acorns in water to check for viability? Does the float test work?
Despite it being frequently recommended, the float test is unreliable. The idea is that seeds that have been damaged or degraded will float in a cup of water. Tests show that plenty of viable acorns also float and some non-viable seeds will sink so this is not a reliable test.
What causes holes in acorns?
One animal that makes holes in acorns is the acorn weevil (Curculio sp.), a brown beetle that lays its eggs midsummer inside acorns where the larvae then hatch. Come fall, the acorns fall to the ground, the larval weevils chew their way out of the shell, and escape to finish their life cycle in the soil where the new generation of beetles will emerge. Acorns damaged by weevils are unlikely to germinate. The tell-tale sign are perfect holes in the shell about 1/8-inch in diamter.
Do acorns require cold stratification to germinate?
Most acorns from red oaks require 1 to 2 months of cold stratification for the acorn to sprout. This can be done outdoors in a cold climate or inside using your fridge. Acorns from white oaks germinate immediately in fall without cold stratification.
Should I remove the acorn shell (outer coating) before germinating the seed?
No, do not remove the shell. The germination process gradually penetrates the shell with moisture, allowing the seed the swell and grow.
How long do acorns take to germinate?
Germination times depend on the species and conditions. Acorns from white acorns can start growing roots in as little as week, sometimes right where they have fallen from the tree. Others including red oaks require weeks or months of cold stratification before the acorn can germinate.
Should I prune my oak sapling?
No, do not prune an oak sapling. It’s typical for the plant to grow a strong, main stem (“leader”) with leaves. Lateral branches will form eventually without any pruning required.
Should I fertilize my oak sapling?
You should not need to fertilize your oak sapling. Many native trees like oaks do not like or tolerate high nitrogen fertilizers and instead do best in nutrient-poor soils.
When is it time to plant an oak sapling in the ground?
When an oak sapling has a strong stem—at least a foot tall—and several leaves, it’s ready for planting in its life-long location. Grow your oak in as large a pot as you can manage so there is plenty of root space. Transplant your sapling before it becomes rootbound.
How long until a new oak tree produces acorns?
It depends on the species. Some oak trees produce their first acorns within five years, others can take up to 20 years or longer.
How often do oak trees produce acorns?
Some oaks produce acorns every two or three years.
Some white oaks produce acorns every four to six years.
Some years will be mast years where the oak produces a prolific number of acorns, followed by one or more years with few or no acorns.
Which animals eat acorns?
There are dozens of species of wildlife in North America that eat acorns including squirrel, deer, bear, rabbit, chipmunk, mice, mole, and several bird species. Acorn-loving birds include blue jays, red-bellied woodpecker, white-breasted nuthatch, tufted titmouse, and more. Blue jays have a symbiotic relationship with oaks where they carry and disperse acorns away from the mother tree helping propagate oaks throughout their territories.
How fast do oak trees grow?
How fast oak trees grow varies greatly depending on the species and growing conditions.
In general, red oaks are the faster growing oak trees with some reaching heights of 20-feet in as little as five years.
White oaks are the slower growing oak trees and may reach 20-feet tall in approximately 30 years.
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Read & See More
Field Guide To Native Oak Species of Eastern North America | USDA (PDF format)
The Nature of Oaks: The Rich Ecology of Our Most Essential Native Trees | Doug Tallamy (book)
About Oak Trees: Natural History, Ecological Benefits, & Mast Years | Empress of Dirt
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Grow An Oak From An Acorn
Supplies & Materials
- Label food bag or container with name of oak species (if known).1 large Plastic food bag
- Place acorns sandwiched between sheets of moistened paper towels.6 sheets Paper towel, 20 Acorns
- With acorns covered, place everything in food bag or container in fridge. Do not seal bag or use a lid: you want some air circulation.
- Set reminder in calendar or phone to check acorns every few days.
- When acorn root or shoot is around two-inches long, plant in potting mix approximately one inch deep below surface with roots aiming down.
- If mid-winter, grow oak sapling in sunny window, never allowing soil to dry out. Otherwise grow outdoors in part shade.
- Oak can be transplanted to final location in garden when approximately a foot tall with several leaves and/or prior to becoming rootbound.