Organic Liquid Fertilizers I Make For My Plants

Using organic liquid plant feeds is a natural way to deliver a boost of nutrients to specific plants at a particular time.

Woman cares for plants, watering green shoots from a watering can at sunset. Farming or gardening concept
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Taking care of fertility in an organic garden is not that complicated. The main strategies for fertility that I use in my own garden are mulching, companion planting and holistic planting design, cover crops/green manures, dynamic accumulators (plants that gather beneficial nutrients from the soil) to chop and drop, and organic liquid plant feeds. Making and managing fertility systems and protecting and improving the soil are among the most important tasks in any organic garden.

The great news is that in a well-planned garden, you should not need any external materials to make your own organic liquid feeds. Following, I will talk about why making organic liquid feeds is such a good idea, and how I do so in my own garden.

Why Make Your Own Organic Liquid Feed?

In organic gardening, we often think longer term. We make sure that through adding slow-release fertilizers like compost, well-rotted manure, and other organic matter, we maintain the balance of nutrients available in the soil for the uptake of our plants.

Sometimes, however, plants may require a boost in the short term. Using organic liquid plant feeds is all about delivering particular nutrients to specific plants at a particular time. The nutrients in a liquid fertilizer will be available to plants far more quickly. And yet unlike synthetic liquid feeds, these organic alternatives are a sustainable and eco-friendly solution.

Understanding Fertility: What Plants Need

All plants need nitrogen, phosphorus, and potassium (NPK). These three key nutrients are the basis of commercial liquid feeds. However, it is important to avoid oversimplification, and in addition to these three key nutrients, there are a further range of micro-nutrients that plants require (and that we must obtain from them). Reducing fertility needs to NPK formulae can be reductionist and can lead to a range of problems. The key to organic fertility lies, as in so many things, with diversification.

Fortunately, novice gardeners will not usually have to delve too deeply into plant nutrition to grow healthy and productive crops. Simply take care of your plants, and – most importantly – your soil, and it will continue to look after you. Making liquid plant feeds is part of that picture.

Making Compost Tea

Making your own compost is important in an organic garden. And no matter how or where you do so, it can help you recycle nutrients in your growing areas and maintain fertility. Compost is added as a mulch or used to top-dress growing areas in a no-dig garden – I spread compost (made with vegetative materials and well-rotted chicken manure and bedding) across my annual growing areas each spring, and in gaps throughout the year. But I also use some compost to make a relatively balanced, multi-purpose liquid feed.

Making compost tea could not be easier. It simply involves adding some of your compost to water to make a liquid that delivers the nutrients plants need. Of course, the nutrient composition of a compost tea will vary depending on your compost. But it can be a useful boost for many plants.

I usually fill a container 1/3 full of compost, then top up the remaining 2/3 with rainwater. I give it a good stir, put on a lid, and leave it for a couple of weeks. I then strain the particulates from the liquid and use that liquid within a couple of days to water my mature plants.

Another interesting thing to consider is that compost tea can be used to steep charcoal, to make biochar, which can be a very useful soil amender in some areas.

You can also use leachate from a composting container or wormery, and dilute this to make a compost tea. The compost tea should bring benefits, as long as you are creating a good quality compost in your composting system.

Plant-Based Organic Liquid Feeds For Your Plants

A flowering Comfrey plant, Symphytum, growing in the wild in the UK.
A flowering Comfrey plant, Symphytum, growing in the wild in the UK. sandra standbridge / Getty Images

I also add plants to water to make organic liquid feed. For example, I make a comfrey tea. Comfrey is a well-known permaculture plant that has a range of uses in an organic garden. While it is not the most effective dynamic accumulator, it is relatively good at gathering potassium (and a few other nutrients), and with its deep roots, can gather a proportion of those nutrients from deep below the soil surface, where other plant's roots won't reach.

I use comfrey liquid feed as a boost for tomatoes, as an alternative to tomato fertilizers. It is beneficial to a range of flowering and fruiting plants. I generally harvest comfrey twice over the summer and use some as mulch. Some I add to water to make my liquid feed. I simply place comfrey, chopped up, into a large bin with a lid, covering it with water. Then dilute the stinky solution to use as a liquid plant feed after around 4 to 6 weeks.

I also make a general-purpose, nitrogen-rich "weed feed" for leafy crops and other nitrogen-hungry plants. This simply involves adding stinging nettles, plantain, dock, goosefoot, chickweed, and other weeds to water. Then, as with the comfrey tea, dilute this and use it to water my plants.

Seaweed Plant Feed

Finally, I sometimes use seaweed sustainably collected on our local seashore to make a seaweed liquid feed. Seaweed contains micro-nutrients, and trace elements not present in other garden plants. It can, where available, be very useful for boosting fertility in your garden.

I steep seaweed in water for a couple of months, then dilute it at a ratio of 1 part seaweed mix to 3 parts water and use it as a general-purpose feed in my garden.

These are just a few examples of the organic liquid plant feeds you can make at home. But they should give you a good starting point for your own experiments.