Could You Grow Your Own Soap?

Could you grow your own soap? A fun but practical blog to look at which plants and other garden items you could use to make soap. The finished product may not be good for the guest room, but you should certainly be able to grow and make soap which is fine to use for floors and more.

The plants I’ll suggest are ones that are easy to grow in the United Kingdom. They’re also able to be turned into a soapy liquid without needing extra ingredients such as oil and lye. And I’ve thrown in a few spring cleaning tips for your garden too. But we’ll start with a quick look at the history of plant-based soap.

A Brief Look at the History of Soap

“Soap is perhaps the first manufactured substance with which we come into contact in our lives and it remains a daily necessity thereafter.”

John A. Hunt

We have been using soap, rather than just water, for cleaning at least 5000 years. Originally this may have been for ritual cleansing rather than personal hygiene and clothes washing.

Wood ash appears early on mixed with boiling fat such as tallow, for example in Babylon as early as 2800BC. Whilst still plant based (trees!) the scouring effect of the ash would not have been pleasant on the skin although fine for cleaning temples and washing clothes.

soap stacked for drying in 100s of years old method, photo taken c 1900 – 1920

Classical Era

The Ancient Egyptians, Greeks and Romans used a combination of scraping the skin to remove dirt, certain soft clays to exfoliate, steam (sauna type, think Roman baths) and soap. Cleopatra bathed in donkey milk not to get clean but to preserve her youthful looks.

Soap was certainly known and used during the Roman period. There was a soap factory in Pompeii. But we have to get to the 4^th century before there is mention of the trade of “saponarius” or soap maker.

Unless scented with oils, and fully filtered these early soaps would have been harsh on the skin. However, archaeology shows that the Romans used to plant Soapwort, Saponaria officinalis, near their bathhouses to use the leaves as part of the bathing process. We also know that they used Olive oil and fine wood ash to create soap. With this knowledge we can see that the question could you grow your own soap is not as daft as it may have originally sounded.

Dark Ages & Middle Ages

Which in Europe is roughly from the Fall of the Roman Empire c500CE to the Italian Renaissance in the fifteenth century. There is of course a difference between commercial soap production and homemade soap. Whilst the latter would have been pretty continuous, soap factories seem to have disappeared from Europe during the early part of the Dark Ages.

But by the end of the first millennium, soap was being produced in Marseilles and Savona. In Britain references appear in literature at the same time, and by 1192 there were sufficiently large numbers of soap makers in Bristol for the unpleasant smells to be commented upon.

Renaissance to Victorian Times

Although London and Bristol became the major producers of soap in Britain, there were centres in other towns and cities such as Coventry.

As with many trades, soap producers tended to be in the same locality, so we find road names such as Soper’s Lane in Cheapside, London.

The Bristol Company of Soapmakers for 1562-42 records more than 180 individuals who were engaged in the trade, including longstanding families in the business.

These commercial soap producers were taxed, a useful source of revenue. To the extent that the soap pans (large open vats) had to be locked and an excise official in attendance at each soap boiling! It wasn’t until the Victorian concerns about germs, infection and cleanliness that the soap duty was cancelled. This was in 1852 and the tax revenue then stood at £1,126,000 pa.

Of course this commercial soap involved various chemicals with which we are not going to get into with our homemade soaps and the plants to grow to use in them.

The Plants You Need to Grow Your Own Soap

Saponins are surface-active compounds with a similar chemical structure as soap, typically occurring in the tissues, roots, flowers, fruit, or seeds in more than 100 plant families. How to make soap from these plants is covered in the section following our plants.

Indeed, there are so many soap-worthy plants that are also pollinator friendly and ornamental that I shall give them a blog to themselves to do them justice (or you’d be sitting here reading this blog all day). The four below are native or naturalised in the United Kingdom.

Soapwort

Saponaria officinalis is also known as soapwort, crow soap, wild sweet William, bouncing-bet, soapweed, and is native to Europe, and parts of Asia. It has been one of the most used plants for soap, for both people and their clothes.

The plant grows best in in some shade, for example under a hedge or deciduous trees. A damp soil is preferred but the pH is not critical. If you have a smaller garden it may be better to grow it in large containers as it can be a spreader.

Ragged Robin

Lychnis flos-cuculi, other common names include crow flower and meadow pink. Still found in damp sunny meadows, this British native makes a good perennial for pond margins and bog gardens. Bubble-gum pink is the ‘natural’ colour, but a white form can also be found.

As well as being an excellent source of nectar for moths and bumblebees, it’s also a food source for bats. The roots are used for soap.

Bracken

Pteridium aquilinum, is another native plant, whose leaves are well known for use as animal bedding. The rhizome is rich in saponins and used for soap; the roots to make glue.

Horse Chestnut

Aesculus hippocastanum a naturalised British plant rather than native, it has long been used for soap. The seeds, ie conkers, are rich in saponins and make a fairly effective cleanser although the conker smell tends to linger.

You’d need a large garden to grow your own Horse Chestnut tree, but there is always the option of responsible foraging.

Grow Your Own Soap

Particularly in regard to smaller scale production, the basic recipe for making soap has not changed for thousands of years. Liquid soaps made with saponin rich plants do not need complicated processing equipment.

Saponification is what gives soap its sudsy cleaning action. And we can combine plant material with one or more of water, ash, oil or animal fats to create that. So that when wetted and mixed, or ‘agitated’, saponin-rich plants create a nice foamy lather that can be used as a gentle cleanser.

NB do not drink the soapy liquids or allow children or pets to do so. Keep the liquid away from fish and wildlife ponds too. Saponin is a toxic glycoside and though it may not kill you if ingested, it will cause nausea and worse. But don’ t let this put you off having a go. If you read the labels of most proprietary soaps for the garden and clothes washing, you’ll find they have this warning too!

How to Make Soap

But if you fancy a go at making your own soap with any or all of the plants above, the process is simple and quick.

Method

Although rubbing the relevant part of the plant in your hands and adding some water will give you soap, to use it for cleaning plant pots and so on, you need a larger amount. Quick methods for making a soapy liquid form each of our plants is as follows.

Soapwort – chop up roots, leaves and flowers (whichever parts you’re using depending on the season)
Ragged-Robin – chop up roots
Bracken – chop up the rhizome into small pieces
Conkers – soak overnight to soften them before chopping.

NB keep different plants separate if you’re doing more than one type at the same time.

Place the chopped plant parts in a pot of hot, nearly boiling, water. Stir well to create a soapy lather.

Strain out the plant debris and allow the liquid to cool before using. If the lather isn’t easily forming, then strain out the debris after the water has cooled.

Tip for Winter Soap making

Gather horse chestnuts in autumn and store for later use.
Grind them up in the blender, then air or oven-dry until they are completely dehydrated. Store in an airtight jar.
When you need a soapy solution, take 1 -2 tablespoons of crushed conkers per cup of boiling water and stir. Strain before using.

Garden Spring Cleaning Tips – Where to use your homegrown soap

The first time I use these liquid soaps on a new surface, I dilute them and carry out a spot check.

They are fine to use on most floors inside your house.

In the garden –

NB, be sure there is no water run-off into garden ponds and streams

paths, patios, decking, drives
garden furniture
shed, potting sheds
greenhouses – frame, staging, floor
garden tools
plant pots
seed trays, gravel trays, seed sowing equipment

These soapy solutions can be used on glass too. And if used with a stiff brush, make removal of mould and moss an easier task. Because of the anti-fungal properties of saponin, mould regrowth is slowed down.

Some people may have skin that reacts with these saponin soaps; others may enjoy a softer skin. It could go either way, so you may prefer to wear gloves as you would do when washing the dishes.

And finally

Growing your own soap isn’t all you can grow – what about growing your own broom for sweeping the dust away? (see link below) You could use it at Hallowe’en as a prop for your fancy dress party too…

But back to gardening related matters. If you would like help with designing a practical, pretty, fun garden or learning how to grow a range of useful plants do get in touch. We offer both planting designs and 1-2-1 gardening courses to support you and improve your garden.

For further gardening advice and inspiration, check out Plews Potting Shed blogs, including the selection below and our monthly Tipsheet – You could come and find us on Instagram Pinterest and Facebook too.