How to Grow Walnuts

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Time to germination: 5 months to a year
Time to harvest: 10 years
Light requirements: Full sun
Soil: Fertile, not sandy


In North America, the most well-known type of walnut tree is definitely the Black Walnut. There are also White Walnuts, English Walnuts, Heartnut Walnuts and Cannonball Walnuts.

All types of walnuts are quite hardy, and actually require a cold winter in order to thrive. So anyone living in warm climates won’t have much success with their own walnut trees. Walnuts will start to produce nuts at around 10 years of age, give full production at 30 and keep on producing for more than 50 years. Depending on the specific type of tree, they can grow up to 100 feet in height.

Many gardeners consider walnuts to be very “messy” trees, much like pecans. They drop their leaves all through the summer, and will kill nearby plants (more on that below).

Starting Your Tree

If you choose to start your walnut tree from a seed, you will want to either plant your seeds where you want your final tree, or transplant it while very small. Walnuts do not do well at all in containers because of deep tap roots and don’t handle transplanting.

You cannot just pick a walnut from the supermarket and plant it in the ground to start your own walnut tree. Nuts intended for eating will not sprout. Contact your local nursery for untreated walnuts for planting. You can plant with or without the husk still on, though taking the husk off will help the plant germinate.

Plant your nuts in the fall, and protect them from squirrels. They need a period of cold before they will sprout. It only needs to be about 3 inches under the soil. They should sprout in 4 to 5 months, or possibly not until the following year.

You can also buy small seedlings, or larger grafted saplings to get a bigger head-start on your nut crops. Grafted saplings have walnut tree branches grafted to the trunk and roots of another type of tree (which is why the survive transplanting better).

One tree is fine on its own, but if you want a group or stand of walnut trees, you need to keep 20 feet or more between them. A single walnut tree can self-fertilize, meaning you will get nuts even with just one tree. You can get a larger harvest of nuts per tree if you have 2 or more though.

Placement of your tree is more important than with most other nut trees because walnut leaves are toxic. The leaves (as well as the roots) give off a substance called juglone, and it will kill any other plants nearby including the grass. So if your plans include having your nut trees within the yard, or overhanging other plants, you’ll have to pick another kind of tree. Also, keep your walnut leaves out of the compost pile.

Unlike annual garden plants, your walnut tree is a more permanent installation. It’s important to take the necessary time to map out the best location for your trees. There should be full sun (remember to plan ahead by at least 10 years), and no solid rock at least 3 under the surface of the soil. Ideally, your soil will be rich and well-drained but not sandy.

Tree Care

Depending on the age and size of the tree, you may not be able to significantly treat diseases or insect infestations on a walnut tree.

Webworms or tent caterpillars can be a problem if there are too many of them on your trees. They build large tents of webbing, that can house hundreds of hungry caterpillars. Cut any branches off with tents and dispose of them carefully. If the problem is severe, spray the tree with BT (Bacillus thuringinsis) a natural bacteria-based pesticide that will attack the caterpillars. Harsher sprays of Carbaryl or Malathion can also kill them.

Full size trees have very long and deep root systems, which usually can protect them from moisture problems on the surface. But after very prolonged periods of drought, your trees might need some watering. You can end up with “burned” walnuts come harvest time if you let your trees get too dry for too long.

Walnut trees should be left to grow naturally without pruning.

Harvest and Storage

If you didn’t already know that early black dye came from Black walnut husks, you’re going to learn after you try to harvest a few of your nuts.

Initially, your tree will produce round green “fruits” that look quite a bit like tennis balls. These are the walnuts. The green outside husk actually has the nut inside of it. To harvest, you have to wait until they are mature enough to drop off of the tree on their own. You don’t pick them. This can make for a bit of a messy and unpredictable nut harvest.

As they ripen, the green husks will come apart and turn black. It’s at this point that they will stain anything they touch, including your hands. Don’t leave your nuts for too long inside the husks at this point. The oils will seep in through the nut shell, and taint the nut meats. Get the nuts out of their husks as soon as they drop off the tree.

Getting the husks off can be a bit of a chore, and some home gardeners even lay out their nuts out on the driveway and drive over them. There are less drastic measures though. Rolling them back and forth on a hard surface (driveway, sidewalk, large stones), with your foot is a more common method. You’ll need to put your weight behind it though. The nuts and husks will stain your work area, so don’t unhusk your walnuts out on the front sidewalk.

If your nuts have ripened enough to be very black on the outside, you may find worms have made a home in them. These are husk fly larvae and they make husking a bit unpleasant but they don’t represent any danger to the hard nuts inside.

Inside the husks, you’ll find a whole walnut in its shell. Wash off the husk remains and keep your harvest somewhere warm and well-ventilated for a few weeks. Warmer temperatures will mean a shorter drying time. You can check for adequate drying by cracking open a nut and testing the little hard divider that runs between the two halves of the nut meat (sometimes called the septum). That piece should be hard and crisp. If its soft, then your nuts aren’t dry enough. Fresher nuts won’t taste the same, though they can be eaten.

After that, you just have to shell them to remove the edible nut meats inside. Dried walnuts still in their shells will last up to a year.

32 Responses to “How to Grow Walnuts”

  1. jude austin  Says:

    I have bought walnuts in spain, up to july they were fine but now in aaaaugust I have cracked them open and they all have a worm in them plus little black specs which i gues is their waste, what can I do next year when I buy or harvest them

  2. David  Says:

    The only thing I could think of would be to freeze them. Hopefully kill off the worm before it hatches. It no doubt has to mature before any cold period and probably could not stand the cold as a larva.

  3. Shirley Billingsley  Says:

    I planted a walnut that i purchased from the store at Christmas time. In just a few days, i had a beutiful walnut tree. Of course, i gave it away, since i could not plant it in my apartment complex. They loved it.

  4. Hal  Says:

    From Victoria B C Another method of removing husks, put the green nuts into a bucket, and let them ‘ferment’. the accumulated moisture from the other nuts seems to help break down the husk, then wear gloves and strain the nuts from the blackened husks.
    mu walnuts would not survive being driven on by a car. Once dried I can often open them with bare hands, unlike supermarket walnuts.
    and yes, leave space for them to grow. Not too near the road.

  5. Chris  Says:

    Have a question. Staying in a house temporarily, and there’s a walnut tree. I picked up a couple of the “tennis balls” figuring I could plant them in a large pot till I move(unsure when, hopefully few months), then transplant at my permanent residence. Now I see that’s not good…..Is there anything I can do to preserve the nuts till I can plant them permanently? Another quick question, are these toxic to pets, dogs mainly? Guessing not since mine have already discovered them and play and chew on them, but still figured should ask if I need to be picking these things up out of their area regularly. THANK YOU 🙂

  6. Ann  Says:

    We livein Australia where we have a cold winter and hot summer, we have a large walnut tree which is about 15 years old, it produces a lot of nuts, but they fall off the tree when still quite green do not splitnon drying out??? They dry out and turn black but do not split of there own accord, what are we doing wrong

  7. Sally Raspin  Says:

    Dunno, but we have the same problem in southern NSW.We ended up with trays of withered black objects.

  8. Mike  Says:

    It is almost April here in Kentucky and I just located a walnut tree on our farm that has many walnuts in their dried husks on the ground. What would be the best way to remove these dried husks before allowing the walnuts to dry in their shells? I have heard of a method or burning the husks off, but can’t find any internet posting concerning it.

  9. Kay  Says:

    I have many walnut tress growing on our property; what a mess! We have always just picked them up by raking and depositing them down back for the deer to eat. I just read the above article. this is certainly a chore to get a walnut out of its husk. I wonder what procudure the big walnut companies use to get the nuts out. I surely would like to use the walnuts in baking but do not care to “tend” to the nuts over a period of time. ;(

  10. Tudor I.  Says:

    Hello everybody! I live in Romania, here we have quite a lot of walnut trees, some of them even bordering public roads (which is not a great idea as accidents happen). People wait until autumn when the nuts are ripe and the husks begin to crack, then they place large canvas/nets under the trees, on the ground, and use long sticks/poles to shake the nuts off the branches. It’s a rather messy job and can be damaging for the tree if not done properly (you have to hit the thicker branches to shake the nuts while not breaking the branch itself) but speeds up the things. The nuts covered in green husks are left in the open to dry a little so the husks crack even more and can me removed relatively easy. The secret is to chose the right time for this operation. Here in the supermarkets a kilo of dried walnuts is like 4-5 $, and a kilogram of kernels like 8-10 $ (while the average monthly salary is about 470-500$ as of 2013), so walnut can be indeed a very useful tree in a garden, either for eating or selling the nuts…

  11. Marie Williams  Says:

    I’m happy to find this web site. I have some walnuts from a local orchard that are a few years old but haven’t planted any yet. It’s a good thing I waited. I now have enough information to figure out where, when and how I need to plant. I hope the walnuts aren’t to old to germinate. If anyone has more information please let me know.

  12. daymon  Says:

    An old hand crank corn husker works great for removing the husks.

  13. Kathy miller  Says:

    Our thin shelled English walnuts all dry up and the meat is not edible before they fall off the tree or even split out of the husk. Not sue what we are doing wrong

  14. Phil  Says:

    Hi everyone,I live in the northwest of Tasmania and I have a huge walnut tree in the backyard and the nuts are all over the place.
    when we got here (December) they were green husk covered nuts and over the last few weeks (March/April) they have just fallen off the tree and all I have to do is pick them up…(there’s hundreds of them).
    we tried to get the nuts out of the husks when they were black ,but it was too messy so we just waited and down they came. I made i bag out of wire mesh so that they can be dried, as there was to many of them to lay over a table.
    just got to wait now for them to be ready to eat.

  15. Craig  Says:

    Hi everyone. I would love to grow walnuts, but am not sure if the environment will permit it. It is in Namibia/Africa where we have hot summers, lot of sun…short rainy seasons(450mm/year), and winters go below 0 degrees celcius, but allways sunny. Is there a chance that walnuts would grow sucessfully under such conditions? Have seen old oak trees on a farm nearby.

  16. wendy hughes  Says:

    Hi. I live in Louisiana. From what I’m hearing walnut trees are not supposed to do well here. Quite the contrary. We have a black walnut over a hundred and fifty years old, and still growing strong. It gets up to 118°f in the shade here at times. We do have a really nice rainy season however. The way we get the husk off the walnuts is to take the walnut leaves make a light layer place the nuts on it then place another layer of walnut leaves on top. The husk open and completly dry out. Leaving bueatiful nuts. I’m not sure if it has anything to do with the chemicals or the moisture provided by the leaves,but I hope this helps.

  17. Wes Taylor  Says:

    Hi, folks,
    Thank you for “being here”. We recently planted (transplanted, really)a “red” walnut tree, about six feet tall; I was given to understand that “they” don’t bear until ten years old. However, this tree now has a couple of walnuts on it. How can this be?
    Thank you all so very much for your most kind assistance.
    Wes Taylor,
    Santa Rosa (North Bay), CA

  18. Administrator  Says:

    When trees start producing is not a hard and fast rule.

  19. Patsy Denk  Says:

    I have just read everything I was looking for. This is great.

  20. Roger Barnum  Says:

    Occasionally in the late summer we get very strong winds that blow many of our walnuts off our tree but the nuts still have the green husks on them. It has been very difficult to remove the husks and messy too, however, I just saw a video on you tube where a guy put them in a wire basket and used a high pressure washer to remove the husks and it worked great. I tried it and it really works!

  21. Roger Barnum  Says:

    I have a question. I have a friend that has walnut trees that produces lots of very small walnuts that are too small to crack and eat. She asked me what to do and I suggested that the trees just needed more watering. She did that but got the same results. Could the problem be lack of fertilization? I have fertilized mine in the past and last year I got 37 gallons of cracked walnuts.

  22. Bettiann  Says:

    Our walnut harvest this fall was terrific! Some of the walnuts have turned black, flavor has not changed. Ideas on what may be happening?

  23. Kathy  Says:

    Our English walnut tree is 100. It blew over in a storm in 1963 but was pulled back into place with a large tractor & chains. The last few years the walnuts come down in the hull, black & disgusting. This year I sprayed for walnut husk fly. The walnuts are beautiful, with the hulls splitting open & dropping the nut before or when they hit the ground. What a difference the spray made! My question: many of the walnuts are very small. Why?

  24. Rich Gwyn  Says:

    dehulling walnuts–I use a small cement mixer. throw in the walnuts along with a shovel full of coarse gravel and turn it on. In 10 or 15 minutes they’re ready.

  25. Chuck  Says:

    I have an English walnut which I obtained through mail order. The tree is in it fifth year and has “frozen” back each winter. Living in Southeastern Idaho Our Winters can get in below zero at times. Is this common and natural?

  26. Sherry  Says:

    I received an Idaho Walnut tree as a gift from my daughter for Mother’s Day. Is it true that it will not produce walnuts for 10 years?? This shocked me!

  27. newy  Says:

    Witch month do you plant walnuts in Victoria Australia

  28. Administrator  Says:

    trees are best planted in the fall or spring in temperate climates, and at the start of the wet season in tropical climates.

  29. RayP  Says:

    we live in SW France where walnut trees are plentiful. We have 2 trees in our garden & they supply all the nuts we can handle. When we have a particularly plentiful year we crack the the nuts to produce a good kernel & if we gather 25kgs of kernel we then take them to a water mill where they grind & press them to produce walnut oil. !Kg of good quality kernel will produce about 1/2 Litre of oil.
    Walnuts & the oil is a fairly major industry in this part of France, the south Dordogne & Lot et Garonne area of Aquitaine

  30. Denise  Says:

    walnut seeds what a gift from God ! And from my good friend who’s allergic. Here in the west we wait for October a good wind storm or snow storm will bring them to the ground. I can crack them so fast by going to the stem site with a not so sharp perryknife I enter the vein and with a quarter turn opening the walnut remove the little pieces of wood on the sides the walnut falls into my hand.I soak in vinegar water for five minutes heard it kills mold rise and dry on cookie sheets in 250 oven or dehydrator store in one quart bagges.I can I do this when outside is green brown or black I don’t bother storing them whole to much work!I love harvesting walnuts!

  31. Robert Carriveau  Says:

    *I live in Michigan and have 2 English walnut trees.
    At first the shell would open up and the walnut would fall out, Now I have worms getin the husk and it turns black and and hard to get the nut out. Is there a spray i can use and when do I spray them,

  32. Maria  Says:

    Who can Tell when harvest of walnuts in Romania? which mounth?

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