The Casual Gardener: It's important to feed to feed – but not overfeed – your plants

There are different ways to keep your plants well nourished

Well fed plants yield better crops. Picture by iStock/PA

PLANTS, like people, need food to survive. They get their sustenance via their roots, absorbing nutrients as they take up water from the earth. Weeds don't need the same level of nutrients as a crop of potatoes or pumpkins, which is why they prosper so readily.

For garden plants and vegetables, we can provide food in different ways, whether slow release or quick fix.

If you take the long view, the best method is to care for your soil and ensure it remains fertile. The principle here is simple – you aim to return the goodness that the plants take out during their lifespan, which is basically just a controlled version of nature's cycle, where something that once lived rots down over time and becomes the food for future generations of plants.

In the garden, this involves adding organic matter, such as homemade compost, well-rotted horse manure or other substances rich in NPK – the chemical symbols for nitrogen, phosphorus and potassium, the three key nutrients for plant growth. Trace minerals like zinc, copper and boron will also improve your ground's fertility.

The type and composition of soil can influence the nutrient levels and fertility. Loam and clay soils tend to be more fertile, their texture making it easier to hold the desired chemicals and compounds, whereas with sandy and chalky soils, the goodness quickly washes away. The latter can be corrected by adding organic matter that'll improve texture and give the soil greater capacity to retain moisture and fertility.

You can also add organic fertilisers as you plant, throwing in a fistful of bonemeal or fish blood and bone at the bottom of the hole you've dug. Commercial inorganic fertlisers, such as Growmore and sulphate of ammonia, will fulfil a similar role.

It's worth noting, however, that a lack of fertility is rarely the reason a plant doesn't grow, with drought, waterlogging, weather damage and pests much more likely to have an adverse impact on plant health.

If you think your plant is waning and needs fed in a hurry, then apply a liquid fertiliser. Again, there are plenty of commercial products but there are also lots of centuries-old formulas and potions that can be derived from various common plants.

With tomatoes, for instance, fermented nettle tea will deliver all the necessary nutrients for a healthy crop in a single watering. Made by leaving freshly picked stinging nettles in a container of water for a few weeks, this foul-smelling concoction needs to be diluted with 10-20 parts water to ensure your poor plants don't overdose. Some users even claim this same solution will ward off aphids and reduce the likelihood of fungal diseases.

Comfrey leaves will give you a more rounded feed, while those who live close to the coast can make a seaweed solution in a similar fashion. Seaweed contains up to 10 times the level of minerals of its land-based counterparts and is particularly rich in iodine and calcium. Again, ensure the solution is adequately diluted before sharing with your plants.

My personal favourite liquid feed is worm tea, a brown, mead-like solution that gathers in the sump at the base of my wormery. There's even a little tap with which to drain it off into a container for use at a later date. It too will make your plants more pest resistant while adding nutrients and enzymes that promote growth.

When feeding your plants, always ensure they've been watered beforehand and be careful not to overfeed, as you can easily kill them with kindness.

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