Liquid Feeds for Garden Plants

Liquid Feeds for Garden Plants

Liquid feeds provide nutrients in a form that is readily available to plants. They do not really comply with the organic principal of feeding the soil-living creatures, but there are times when the use of a liquid feed is necessary. Vigorous, hungry plants growing in a restricted environment such as a pot, tub or growing bag, for example, will need a liquid feed to keep them adequately supplied with nutrients.

liquid plant food In the open garden liquid feeds may be used where the soil is poor, or applied as a foliar spray where soil conditions or root damage prevent sufficient uptake of nutrients by a plant’s roots.

Liquid feeds are not an alternative to a good, rich potting mix or a regime of long-term soil improvement.

Using liquid feeds

Liquid feeds can be applied to the soil or to plant foliage (foliar feeding). Plants can take up more through the soil but a foliar application can be useful when root action is restricted.

Always dilute liquid feeds as instructed; an overdose can inhibit growth. A liquid of unknown analysis, such as that collected from a worm compost bin, should be used in a very diluted form.

Liquid feeds should be applied to moist potting compost or soil. When feeding plants in the soil, it is a good idea to sink a plant pot into the ground near each plant and feed into this. This takes the liquid down into the soil, and also helps you to measure how much each plant is getting.

The rate of use of liquid feeds will vary with the feed, the fertility of the potting compost or soil, the size of the pot, the type of plant, its stage of growth and the growing conditions. A vigorous tomato plant in full fruit production will, for instance, require a great deal more feeding than a few bedding plants planted in a large tub.


Proprietary organic liquid feeds are available — fish emulsion, plant extracts and liquid animal manures, for example. Where possible, purchase only those carrying a recognized organic symbol.

It is very simple to make your own liquid feeds using easily available ingredients.

Home-made liquid feeds

Comfrey leaves make a liquid high in potash, with reasonable levels of nitrogen and phosphate. It is particularly good for greedy fruiting plants such as tomatoes and peppers, but can also be used more generally. Its nitrogen levels may be slightly low for plants growing in a very restricted environment, such as a hanging basket, which need a lot of feeding.


Nettle leaves (Urtica dioica z 3) make a good general liquid feed, a little low on phosphate, but supplying magnesium, sulphur and iron. Nettles collected in spring contain the highest levels of nitrogen, potash and phosphate. The main disadvantage of this product is its smell. Both comfrey and nettle liquids, being slightly alkaline, are not recommended for use on acid-loving plants.

Liquid feeds can also be made from various types of animal manures. Their analysis varies depending on the manure. Sheep manure is said to make the best, but cow, horse or goat is also suitable.


Liquid feeds can be made by steeping comfrey leaves, nettle leaves or animal manure in water.

You will need: a plastic container of any size, with a lid; comfrey leaves — 3kg (6-3/8lb) per 45 litres (12gal) water or nettle leaves — 1kg (2-1/41b) per 10 litres (21/4gal) water, or animal manure — 4.5 litres (1-1/5gal) tied in a sack per 54.5 litres (14-2/5gal) water. A tap, such as that on a water butt, is useful but not essential.


Place the container in a site where the smell it may produce will not cause a nuisance. Fill the container with ingredients as listed above and replace the lid. The sack of manure can be suspended on a length of rope. Leave for two weeks for nettle and manure liquids, four weeks for comfrey liquid.

Comfrey and manure liquids are used without further dilution. Nettle liquid should be diluted with 10 parts water. Any residue from these liquids can be added to a compost heap.

Comfrey concentrate

Comfrey leaves can also be used to make a concentrated liquid feed. This can be stored for a longer period than the dilute form and it does not need such a large container. Also, it does not smell so much.

Seaweed extract

Seaweed extract is a plant growth stimulant rather than a supplier of plant foods. It contains trace elements and other compounds which promote healthy growth. It has been shown to have remarkable effects on plant growth and pest and disease resistance, though where growing conditions are good it seems to have little effect.

Seaweed extract does not contain the major plant foods and seaweed products on the market sold as liquid feeds, rather than as a plant stimulant, are likely to have had their nutrient value boosted with chemical fertilizers.

29. January 2011 by Dave Pinkney
Categories: Manures and Fertilisers, Soil Cultivation | Tags: , | Comments Off on Liquid Feeds for Garden Plants


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