DIY Garden Fertilizer

 Plants need food,  just like we do, and there are many ways you can make your own fertilizer to help keep your plants healthy and happy. Here are just a few.

Do I need to say it? Organic is best! You can feed the soil but putting toxic chemicals on the plants or in the soil will kill most or all of the beneficial organisms that make soil alive and healthy. Its a complicated, amazing ecosystem that, when cared for properly (organically), will feed and care for your plants as nature intended. If you use chemicals most of this info is a waste of your time and energy. With chemicals you have dirt, not living soil and you will need to add more fertilizer (may as well use the cheap chemical varieties). 

What makes a fertilizer? Anything that adds nutrition. You will see 3 numbers on bags of store-bought fertilizer. They are NPK - nitrogen, phosphorus, potassium. These are the big 3 that are the most crucial but, like us, plants also need other nutrients to be healthy.  If you are having odd problems growing things in your garden I recommend getting a soil test to see if you are low on a specific thing. 

Compost- can be one of the best, but quality and nutrients depend on what goes in to it and how it's made. Compost is NOT the same as rotting, which is a stinky, anaerobic process. Composting is the breaking down/decomposing of natural materials. There are literally thousands of written instructions out there on composting so I won't go into detail here. Many people like to try to make it a complicated process but I'm a fan of keeping things simple so I follow the 50% green, 50% brown/dry mixture ratio, mixed or lightly layered. There are 2 general ways to go, so called "hot" and "cold". Hot composting is faster but requires more work. You make a pile, let it heat up and then as it starts to cool down you turn/mix it, repeatedly, until it breaks down. You want to not be able to easily recognize the original materials. If there are chunky things left over you can sift them out and throw them back in for further breakdown. Fresh, well broken down compost will have many of the nutrients found in the original material plus lots of other good stuff like beneficial bacteria, enzymes, critters and fungus. Cold composting is easier on your back but takes much longer. You just mix or layer your green and brown material and wait. Optimum pile size is said to be 3 feet square. Smaller doesn't heat up as easily, a lot larger can be difficult to break down evenly. Compost is a fantastic soil amendment and mild fertilizer. Can also be made into "tea" by soaking in water. Some like to add other nutrients to the water and a bubbler to add more good stuff. 

Worm Castings- also fantastic and in some different ways. I'm a big fan and have 3 "worm bins" to keep a good supply of castings and "tea" on hand. Decomposing worms are part of natures clean up crew and create a different form of compost called Vermicompost. As they chow down on plant material they turn it into manure which is full of the natural bacteria, fungus and critters present in the soil too, helping multiply these in your garden. They also have an enzyme in their gut called "chitonase" which breaks down chiton, one of the main components in an insects shell/exoskeleton. Many believe this is what helps worm castings act as a natural, systemic insecticide. Whatever the reason, I have seen the effects and they are amazing. All plants seem to love worm castings and you will see rapid new growth and flowers as well as fewer insects. It works better to control White Fly than anything else I have ever used (over 50 years of gardening/landscaping), including toxic chemicals. Whenever a plant looks unhealthy or has bugs I give it some castings (just throw around the root zone and water in) or "worm tea" (foliar spray or watering can, diluted). 

Blood and Bone Meal - back before you could buy organic fertilizers at the store many people would buy these 2 to use. Blood Meal is almost all nitrogen and Bone Meal is high in Phosporus. Together they provide large amounts of 2 of the main nutrients needed. Bone Meal on its own was always recommended for healthy bulbs.

Animal manure - used for millenia as a fertilizer. Manure from all common farm animals is used but only from herbivores. You need to follow recommendations about how to manage the manure before using it as some are too "hot" or salty and need to be aged or composted first or may harm your plants. Rabbit is one of the few manures that can be added straight without harm. Several years ago I adopted 2 abandoned bunnies that needed a caretaker in exchange for supplying me plant food. Love it! Very low odor, easy to spread little pellets and hay, constant supply. Doesn't hurt that they are adorable, friendly, soft little fluff balls.  I also keep chickens and use their manure but it requires composting or aging to use safely. Although highly controversial these days, for thousands of years we have used human excrement as fertilizer also. Urea (urine) is listed as an ingredient on many fertilizers and I chuckle at the popular term "Humanure". Many people don't know that the popular, local, So Cal garden brand Kellogg used human waste from the Hyperion Plant in most of their products for decades (maybe still do?). "Nitrohumus" was mostly, if not all, sewage sludge. Thats why they became the dominant brand here, because their fertilizer source was free "Humanure".  PS: other products such as  "Milorganite" is similar. Main issues are contamination from chemicals and medications and possible spread of diseases and parasites.

Rotting plant juice - one method that is recommended by many is to add high nutrient plants to water, cover, let it sit for awhile (days or weeks) to release the nutrients into the water, strain, dilute and use. The major downside to this method is the horrendous stench of rotting plants. My nose can't handle it.

Korean Traditional Gardening techniques - this part of the world developed some different ways to improve soil and plant health which were not well known here in the US until fairly recently. One which I have used is called FPJ or Fermented Plant Juice. As soon as I read that it didn't smell horrible I had to try it. Rather than the plants rotting in water (an anaerobic, stinky situation), they are fermenting to extract the nutrients and add beneficial probiotics/enzymes/etc. You simply add sugar to the plant material and water and let sit for awhile, stirring as often as you can, then strain and use. You should dilute this liquid (opinions vary but at least 10 times seems to be the minimum) and then can spray as a foliar feed or water around the base of the plants. Your imagination is the only limit to the ingredients. 

Another method is to simply drop plants on the soil and let nature and critters slowly break it down. It will be mulch at first and eventually compost. Permaculture came up with a term that always makes me chuckle, "Chop n'Drop". I do this all the time in my own and some clients gardens. One of the best things you can do for a plant is let it's leaves/flowers/debris stay on the soil, break down and recycle the nutrients that it had taken up to create it. There are some exceptions such as diseased or insect covered foliage, which should usually be removed. You can also use other plants that have nutrients you want to add.  Some plants pull lots of nutrients from the soil or air and then can be used to add them back in. 

Nitrogen-fixing plants, mostly in the legume family (bean/pea) have nodules on their roots that gather nitrogen they collect from the air. When the plant dies or is stressed it can release some of that nitrogen into the soil to be available to other plants. Beans and peas are the most talked about but there are also perennial bushes and trees for long term use. I started growing a few Alfalfa plants in my garden, one of the most efficient nitro fixers and great for your health because of all the nutrients it pulls up.

Cover crops - called "green manure" by some, these are plants that are grown specifically to chop n'drop or turn under to compost in place. Many are chosen for specific purposes such as Daikin Radish with deep roots that help break up heavy soil or legumes that will add nitrogen or ones that pull nutrients from deeper than usual.

High Nutrient Plants/Biodynamic Accumulators:

Comfrey- queen of hi nutrients, deep roots pull nutrients from lower than many can reach. Often recommend as a fertilizer all by itself. Also highly medicinal. 

Borage - a cool season annual that self-seeds freely, is edible and medicinal. Is it invasive? Depends on you perspective. I do chop n'drop, feed it to animals, worms and the compost pile as well as put it in Oxymels so the more the better in my garden.

Alfalfa - a healthy superfood, nitrogen fixer, animal favorite.

Most "weeds" including stinging nettle, chickweed, purslane, dandelion, motherwort, lambs quarters, mallow, thistle, wild lettuce, etc. Many have medicinal value too!

Aquarium and pond water is full of nutrients unless you have lots of plants which are taking them up. When doing a water change, throw it on your garden.

Pond/water plants- they pull and accumulate nutrients from the water (think fish, snail, bug, etc). The floating plants Duckweed and Azolla are almost 50% nitrogen (protein), which is much higher that most plants. Commonly used as a fish and livestock food and maybe human soon also. Water Hyacinth are being used to make a fertilizer in SE Asia. Most water plants are very fast growers, considered invasive, but I use my extra for food and fertilizer. My Koi would eat as much as I would give them and the chickens love them too.

Kelp/algae - fantastic mineral accumulators. Make sure to wash well to remove the salt.

There are many more methods and great plants. Feel free to leave a comment or add your favorite or unusual way or plant. Also, let me know if there is a particular topic you would like me to cover.

Happy gardening!