Question
Are there any household products - things you would find int he cupboard - that would work as fertilisers?

Answer
Absolutely! The BEST fertilizers money can buy are right there in the kitchen.  Not the cupboard perhaps - unless you're made of money - but the garbage pail.

Vegetable scraps and leftover salads.  Old, stale spices and herbs.  The used Coffee Grounds and Tea leaves from the morning breakfast (and the undrunk Coffee and Tea).  Dry, moldy bread.  Orange juice, Apple juice, Pineapple juice, frozen vegetables past their expiration date.  The end of the bottle of vinegar.  Potatoes at the bottom of the bag you bought last month with sprouting eyes or traces of green on the skin.  All of it goes into a Compost pile in the corner of the yard, and in a year you have the ultimate Humic Acids producer, ready to feed your Soil, build goodwill with your Earthworms, waste not.

Remember that this Thanksgiving as you're peeling off the imperfect, rust-kissed outside layers of Lettuce for the Salad.

Save those potato peels when you're starting the Mashed Potatoes.

Celery tops, Onion skins, Pineapple cores.  These hold all kinds of complex trace minerals and macro elements that your Soil will save for the right plant.  Could be Grass.  Could be a favorite Rose.  You'll find something.  Top dress, let the Earthworms do the heavy lifting, and you're in business.

Let's get to ways you can use Baking Soda.

Sodium Bicarbonate - NaHCO3 - is one of those kitchen remedies that are so much fun to use.

Nevertheless, this is a SALT that you have to be very careful with.

As you can imagine, it does some damage.  And as you DON'T see, it does OTHER damage - to microbes in your soil that are part of the natural balance.

Those microbes have everything under control, until you come along with concentrated fertilizer (SALT) or Baking Soda (SALT) and a whimsical idea about killing a Fungus or Mildew.

Mixed with water and dishwashing liquid in the right proportions, Baking Soda alters the pH of a Peony or Rose leaf, and makes it hostile to Powdery Mildew and other Fungi and Molds.  Yes, Baking Soda works.  But personally, I think Compost Tea works better.  Maybe I just had a good year with it.  Both of them were studied at major research centers, and both got thumbs up from the scientists for inhibiting Fungal populations in experiments at university centers.  Say Yes to Baking Soda.

I know somewhere you're reading between the lines here, looking for the word SUGAR.  Sugar ain't cheap.  It doesn't spoil.  And bacteria can't use Sucrose -- they're VERY big on Glucose, especially when they're making Petri dishes with the stuff.  Fungi can use Sugar.  But in a nutshell, using large quantities of Domino's Cane Sugar to 'feed' your microbes as though they were the neighborhood cats -- well, it does not cut the mustard here.  I could go on but we have miles to cover here so we'll move on.

Now, I want to mention a few items in the house that would not be as good an idea as some people tend to believe.  Starting with Epsom Salts.

If Epsom Salts had a fan club, Jerry Baker would be its president.  Baker, who calls himself 'America's Master Gardener' and has amassed a following and a fortune probably in the millions with his simple, easy style, recommends you use Epsom Salts for all kinds of problems.  This is after all pure Magnesium Sulfate.  Use it whenever you need Magnesium.

Questions is, DO you need Magnesium?

Odds are, No, you do not.

Magnesium comes FREE from God in most soil around here, and probably where you live, too, Tom.  People who live near the beach, with very SANDY soil (which has a grossly LOW Cation Exchange Capacity and can't hold onto minerals), do sometimes have to deal with real Magnesium deficiencies in their crops or gardens.  But that's because Magnesium drains right out when you put it in Sandy Soil.  Those particles of Sand just cannot cling to the Magnesium particles.  And the Magnesium washes out.

Know what else?  Epsom Salts does the same thing.  It dissolves, and it washes out of your house.

Now, Magnesium is a VERY important Minerals where plants are concerned.  For starters, you can't make Chlorophyll (C55H70MGN4O6) without a Magnesium molecule.  But it does not take much, if you look at that chemical formula for Chlorophyll.  In fact, you only need ONE atom of Magnesium to make a molecule of Chlorophyll.  Most Soil has plenty of Mg.  Scratch the Epsom Salts.  It's entertaining, but worthless advice.

Now, let's take a look at the Listerine, another Jerry Baker signature concoction.  In a nuthshell, Listerine contains large quantities of alcohol.  We use alcohol as a disinfectant because it kills germs.  Germs are bacteria -- and remember, we work hard to BUILD UP the bacteria in the soil as part of the microherd.  Ethyl Alcohol kills Bacteria and Fungi on contact.  Most Bacteria in the soil is beneficial.  How can Listerine be good for the Garden or the Lawn?

Finally, a word about household Ammonia.

Ammonia (NH3) is a caustic poison that does the same damage that any concentrated Chemical fertilizer in a bag labelled by Scotts or Ortho would do.  It is true that plants do not care where their next Nitrogen fix will come from, but the microbes in the soil do.  Ammonia is a byproduct of anaerobic decay; most HARMFUL Bacteria, as I understand it, prefer Anaerobic bacteria.

Sure I've left something out.  Followup questions invited.  Thanks for writing, Tom.