Treat Nutrient Deficiencies In Plants

Yellowed leaves, poor fruit set or a failure to thrive? It could be something your plants didn’t eat

Plant with diseased leaves, Treat Nutrient deficiencies in plants, Handyman magazine,

Treat nutrient deficiencies and get your plants thriving again. Image: Thinkstock 

When you have followed all the rules on the label for your plant but it’s still in poor health it could have a nutrient deficiency. 

These occur when the soil is lacking one or more of the nutrients the plant requires to thrive. 

Deficiencies often show up in the leaves, which may be discoloured, distorted or dropping off. 

The oldest leaves can show problems best where deficiencies have built up, though certain problems, like calcium deficiency, show first in young leaves.

A plant nutrient is any element required for normal growth. The air supplies the essential elements of carbon, hydrogen and oxygen but others are supplied by the soil. 

Synthetic or organic fertilisers can prevent or treat deficiencies. 

Some sap-sucking insects, fungi and diseases can cause similar problems, so look out for them, too. 

And check that you haven’t over or under-watered, which can also cause foliage problems.

Grow healthy plants 

Improve your soil by adding well-rotted manure or compost, and spreading organic mulches or leaf mould around existing plants. 

Digging it into the soil to a depth of 50mm can help to keep any nutritional problems at bay. 

For gross feeders such as citrus, bananas, hibiscus, zucchini and tomato, just use a good quality complete fertiliser designed for that plant. Or target the problem and treat specifically.

TIP Always water plants well before and after feeding.

Feeding pot plants 

Plants growing in pots rely on us to keep them healthy. Nitrogen is often lacking, as decomposing potting mix can use it up, keeping it from hungry roots. 

Fertilise container-grown plants regularly when they’re actively producing new growth, generally from spring to autumn. 

Use a gentle liquid fertiliser or a pelletised organic variety, as salt-based fertilisers can burn confined roots and leave excess salt crust on the pot and mix.
 

Detecting and treating deficiencies 

Look for these symptoms in your plants to identify nutrient deficiencies in the soil. Confirm your diagnosis using a soil test kit before applying the remedy, then treat at the recommended rates.

Nitrogen 

Older leaves yellow at the bottom of the plant with others pale green. Slow, spindly growth may appear.

TREATMENT Blood and bone, manure and fertilisers containing nitrate, ammonium or urea. 

Plant with nitrogen deficiency, Treat plants with nutrient deficiencies, handyman magazine
Plants with nitrogen deficiencies have older leaves yellow at the bottom of the plant with others pale green. Image: Getty Images
 

Magnesium 

Leaves turn yellow between the veins and the plant suffers from slow growth.

TREATMENT Epsom salts and dolomite. 

leaf with magnesium deficiency, treat nutrient deficiencies in plants, handyman magazine
If a plant has a magnesium deficiency its leaves Leaves turn yellow between the veins. Image: Getty Images
 

Phosphorus 

Dark red-purple leaves with older leaves looking burnt at the tips and poor fruit set.

TREATMENT Phosphate, manure and bone meal. 

plant with phosphorus deficiency, Treat nutrient deficiencies in plants, handyman magazine,
Plants with phosphorus deficiencies have dark red-purple leaves with older leaves looking burnt at the tips. Image: Getty Images

Potassium 

Yellowing between leaf veins, plus scorched and curling leaf edges and pulpy fruit.

TREATMENT Manure, seaweed extracts and sulphate of potash. 

plant with potassium deficiency, treat nutrient deficiencies in plants, Handyman magazine
Potassium deficiencies in plants are seen in a yellowing between leaf veins, plus scorched and curling leaf edges and pulpy fruit. Image: Getty Images

Calcium 

New growth is distorted and can yellow and die, and fruit is afflicted with blossom end rot.

TREATMENT Lime, gypsum, dolomite and crushed eggshells. 

plant with calcium  deficiency, treat nutrient deficiencies in plants, Handyman magazine
In plants with calcium deficiencies new growth is distorted and can yellow and die, and fruit is afflicted with blossom end rot.Image: Getty Images

Iron 

New leaves pale between veins to light green, yellow or white.

TREATMENT Seaweed extract, iron chelates, and ammonium sulphate and compost to lower pH. 
 

plant with iron deficiency, treat nutrient deficiencies in plants, Handyman magazine
In plants with iron deficiencies new leaves pale between veins to light green, yellow or white. Image: Getty Images

Vote It Up: 

See also

Eradicate Aphids

Learn how to get rid of this common garden pest. Image: Thinkstock

Aphids are small, soft-bodied insects that feed on sap and leave a sticky deposit as they suck the juice from leaves and stems...
A flower with powdery mildew, How To Get Rid Of Powdery Mildew, Handyman Magazine,

Keep an eye out for powdery mildew when the humidity is high and the weather has been dry. Image: Getty Images 

First appearing as faint white spots on leaves, this fungus gradually forms a white dusty film over the entire surface....
Plant with diseased leaves, Treat Nutrient deficiencies in plants, Handyman magazine,

Treat nutrient deficiencies and get your plants thriving again. Image: Thinkstock 

When you have followed all the rules on the label for your plant but it’s still in poor health it could have a nutrient...
Anyone who’s had a citrus tree will be familiar with bronze orange bugs. Also called stink bugs, they produce a foul-smelling...
A snail trap in the garden

Homemade traps and sprays work well in the garden

Using environmentally sustainable sprays, traps and deterrents to control insect pests and diseases is good garden practice....
A hoverfly on a leaf

Hoverfly larvae feed on aphids and thrips

Organic gardening combines several complementary strategies to achieve healthy crops. These strategies consist of an array of...