Money doesn’t grow on trees, but soap does. Soapnuts, or soapberries, have become popular over the last few years in western culture, but they have been used for thousands of years by many other cultures worldwide.
If you’re looking for an eco-friendly soap that you can use for many applications in your home, soapnuts are an awesome option you can grow yourself.
They’re also perfect for survival gardens or if you have a septic tank that doesn’t do well with chemical soaps.
What is a Soapnut Tree?
Soapnut trees and the berries from them are called many names, including soapberry, soapnut shell, soapberry nut husk, and Chinese soapberry.
Soapnut trees are deciduous and grow up to 60 feet tall (though some are more compact), and start producing nuts (actually drupes, which are similar to berries) in three to nine years.
The shell, or the outer layer of the drupe, contains saponin. This creates a soaping effect when the shell is mixed with water.
The resulting suds are totally natural and can replace many chemical-laden products that are bad for the environment and your health.
There’s a soapnut tree called western soapnut that was historically used by Native Americans for washing, and many Asian cultures used it for the same. So you can tell that this plant has a long, reputable history.
Today, people use soapnuts for cleaning laundry, as a shampoo or body-soap, and for many other cleaning projects.
Varieties of Soapnut
There are four main varieties of soapnuts that grow in North America. There are also other varieties native to India and other countries that you generally don’t see outside of those countries.
Sapindus saponaria is the variety that grows in Mexico and the southwestern United States. It’s the variety I suggest you grow if you live in those areas.
This variety grows in USDA Zones 6-9.
Sapindus marginatus is found in the area of Florida to South Carolina. It loves the temperatures and humidity in the area, so it won’t do as well in dry areas.
Suitable for zones 6-9.
Sapindus oahuensis is native to the Hawaiian Islands and grows well there, but not so much in areas outside of the islands. If you live in Hawaii, pick this one.
This variety grows best in zones 10-11.
A close relative of the western soapberry, Sapindus saponaria var. saponaria is found predominantly in the Florida Keys, Central America, and the Caribbean Islands.
Grow in zones 6-10.
How to Plant Soapnut Trees
Although soapnuts take a few years to produce, they’re worth it because they’ll provide their eco-friendly cleansing berries for years. No more needing to wash and clean with chemicals.
You can grow soapnuts in containers for a couple of seasons, but they’ll soon outgrow the pots. Plus, they don’t transplant well because of their long taproot. Your best bet is to start them in their final spot.
Plant in full sun with some partial shade during the heat of the day. My soapnut tree gets four to five hours of sun a day, with afternoon shade, and it’s happy as can be.
Soapnut is forgiving and will grow in most soil types as long as the earth holds moisture but drains excess water away. Acidic, alkaline, loamy, moist, sandy, and clay soils all work as long as you have good drainage.
If your area has a native soapnut variety, grow that particular one for the best chance of success. Plants in their native home tend to have fewer pests and diseases and need less pampering.
There’s a little bit of work to getting soapnut seeds to grow, but it’s the best method, and if you do it right, the germination rate is high.
You can use a seed collected from the berry or nut of the tree, or you can buy them (they’re sold at many places these days). Do this process in the spring (or early summer in cooler areas).
- First, you need to scarify the seed to weaken the hard outer layer. Use a nail file or fine sandpaper and scrape the drupe’s hard outer shell, scratching it all over. Some seeds are so hard you may need to damage them slightly with a hammer. Be gentle. All you want to do is weaken the outer layer, not break them open.
- Next, fill a jar with hot water (not boiling), place the seeds in, and seal with a lid. Leave for 24 hours. This is crucial because the hot water activates the seed to get it to germinate.
- Plant one inch deep in deep pots filled with good quality seed raising mix. The pot must be deep due to the long taproot soapnut trees form, even when small.
- Water regularly and don’t allow the soil to dry out as the seeds germinate. Keep in a spot with bright, indirect sunlight.
- When the plant reaches three to four inches, transplant it to its permanent home. Be careful not to damage the taproot and harden it off for a few days.
If you’re lucky enough to find seedlings of soapnuts, go for this method and then experiment with seeds later.
Make sure you dig in plenty of well rotted organic fertilizer before planting.
Dig a hole twice as wide and deep as the root ball and taproot. Place in the hole and fill in, tamping down firmly. Water often when first planted. Soapnut is drought-tolerant when older, but not when young.
Caring for Soapnut Tree
Soapnut trees are hardy and grow with minimal input, other than watering, once you get them established.
Use a general, all-purpose fertilizer and follow the instructions on how much to use. Water well and fertilize in the spring and fall.
Soapnuts need plenty of water in well-draining soil. They like a lot of water but can’t handle wet roots from standing water. Don’t let the soil dry out too much in the first two or three years.
Prune in the first few years while the tree is at a manageable height. You need to prune to ensure a well-shaped and sturdy tree, but you can let it assume a natural shape once it gets tall.
After that, just prune out damaged or diseased branches.
Companion Planting for Growing Soapnut
Due to the size of soapnut trees, I have opted not to plant anything under or around them because they cast a lot of shade when growing. If you do want to underplant them, use the following berries that suit being planted under trees, especially in a food forest or permaculture setting:
Common Problems and Solutions for Growing Soapnut
Soapnut trees are resilient to pests and diseases and have few problems. Due to the high amounts of saponin, the plant is resistant to issues that plague many other trees.
I’ve never sprayed the tree for any issues at all. The only problems I’ve had are:
If the leaves on the outer branches begin to yellow at the tips and edges, your plant might need more food.
Fertilize with a balanced fertilizer and water well. When I experienced this, the tree recovered, so keep on top of feeding.
Wilting and Scorched Leaves
Failure to water your soapnut tree causes issues like wilted or scorched leaves. Try not to let this happen because often, by the time the symptoms show, the tree is overly stressed.
Make sure you water soapnuts well in the first couple of years, especially in hot and windy weather.
Soapnut trees flower in summer, and you can collect the drupes in early winter. I wait for my soapnuts to drop to the ground before harvesting. They’ll be a little sticky, but you’ll dry them out, so it doesn’t matter.
I’ve seen some people lay a tarp on the ground, climb the trees, and hit the foliage with long sticks. This causes the berry to fall on the tarp.
Either way, collect the berries and lay them out in the sun to dry. Make sure they’re perfectly dry before you collect them for the next step.
Crack them open and remove the seed. The seed can be used for replanting since the outer shell is the only part used for soap.
Don’t worry; you’ll get the hang of cracking them open to get two or three large bits, rather than smashing them into small pieces and powder.
You did it! You’ve planted and raised soapnut trees. Now it’s time to use the drupes to clean.
Place four to six nuts in a muslin bag and put them in the washing machine with your laundry.
Use warm water to wash, as the drupes perform better in warm water, though I do use them on a cold wash as well.
At the end of the wash, remove the bag and allow it to dry. You can use it two or three more times before you need to replace the nuts.
Shampoo, Soap and General Cleaner
Place a handful of shells in a pot with four cups of water. Bring to a boil and then simmer for 10 minutes.
Remove from heat and allow to cool completely. Drain the water from the nutshells. Add one teaspoon of xantham gum or guar gum to thicken the mixture.
You can use this as shampoo or hand soap, so add a few drops of your favorite essential oils to make it smell nice.
Use this liquid as a general cleaner around the house (spot test first) or as a car wash, dishwashing liquid, or pet shampoo.
We’re all trying to decrease our footprint on the world and growing trees that let you cease the use of chemical cleaners is an amazing way to start.
Yes, soapnut trees take a while to produce, but see it as setting up for future years, when you’ll have a regular supply of soapberries.