Plant Nutrition

Fertiliser is not medicine. It supports a plant that is already growing; it cannot fix bad light, damaged roots or a watering habit that keeps the mix soaked. This guide covers what the numbers on the bottle mean, how much to actually give, the iron problem that Kuwait’s alkaline tap water creates in almost every pot, and how to read a plant that is telling you something is missing.

1. Light first, then food

The one ruleFertiliser is not light. A plant in a dark corner does not need feeding, it needs moving.

A plant builds its own sugars from light. Fertiliser only supplies the mineral elements it needs to turn those sugars into tissue. Feeding a plant in a dark corner does not make it grow — it just leaves unused salt in the pot, which then burns the roots. So before you buy anything: is the plant getting bright indirect light for most of the day? If not, move it or add a grow light on a timer for 10–14 hours a day, roughly 30–60 cm above the canopy depending on the fixture. Plants need a dark period too; leaving a light on around the clock is not better.

2. Reading the label

The one ruleN for leaves, P for roots and flowers, K for robustness — and the micronutrients matter as much as the three numbers.

Every fertiliser carries three numbers — N-P-K.

• N, nitrogen — leaves and stems. High N feeds are for foliage plants.
• P, phosphorus — roots, flowers and fruit.
• K, potassium — general robustness, water regulation, disease resistance.

Below those come the micronutrients: iron, magnesium, calcium, manganese, zinc, boron. They are needed in tiny quantities and are exactly where problems appear in Kuwait.

Plant	Look for
Foliage houseplants (monstera, pothos, ficus)	Balanced or higher N, applied at half strength.
Flowering plants and orchids	Higher P and K during budding.
Herbs and leafy vegetables	Gentle, frequent N. Organic feeds suit edibles.
Cacti and succulents	Low N, a few feeds a year only.
Citrus and fruiting plants	A citrus-specific feed with added iron and magnesium.
LECA and semi-hydro	A complete hydroponic nutrient — there is no soil to supply anything.

3. Liquid, granular, tablets or spikes

The one ruleIndoors, a liquid concentrate you dilute yourself beats spikes and granules every time.

Form	How it behaves	Best for
Liquid concentrate	Fast, precise, you control the dose exactly. Needs repeating.	Indoor plants. The default choice.
Slow-release granules	Release over months with warmth and water. Little control.	Outdoor pots and beds.
Tablets and spikes	Convenient, but concentrate the feed in one spot near a few roots.	Large pots, people who forget. Space several around the pot rather than one in the centre.
Organic (seaweed, fish, castings)	Slower, milder, feeds soil biology and is hard to overdose.	Edibles, herbs, sensitive plants.
Root stimulants and mycorrhizae	Not food — they help the root system take up what is there.	At repotting and after root damage.

4. How to feed, without burning anything

The one ruleWater first, then feed at half the label dose. Never fertilise a dry root ball.

1. Water first. Never put fertiliser on a dry root ball. Water, wait an hour, then feed — or feed with the watering itself, as a dilute solution.
2. Start at half the label dose. Indoor plants in pots are almost always overfed. Half strength twice as often is safer than full strength.
3. Measure. Use the cap or a syringe. “A splash” is how roots get burnt.
4. Feed only while it is growing. New leaves unfurling means feed. Nothing moving for a month means stop.
5. Flush the pot monthly. Plain water until roughly twice the pot volume drains out. This is not optional with Kuwait tap water — see the watering guide.
6. Never feed a sick plant. Rotted roots, sunburn, pest damage or a plant wilting in a heat event cannot use fertiliser and will be damaged further by it.
7. Never mix two products unless both labels say you can.

5. The Kuwait problem: alkaline water and locked-out iron

The one ruleYellow new leaves with green veins are iron lock-out, not hunger — flush the pot, then use EDDHA chelated iron.

This is the single most common nutrition issue we see, and it is usually misdiagnosed as “needs more fertiliser”.

Kuwait’s tap water sits around pH 7.5–8 and is mineral-rich. Every watering nudges the mix more alkaline. Above roughly pH 7, iron becomes chemically unavailable to the roots even though there is plenty of it in the pot. The plant then shows interveinal chlorosis: new leaves come out yellow while the veins stay green.

What to do

• Flush the pot to wash out accumulated salts.
• Use chelated iron — EDDHA. Ordinary iron sulphate and EDTA-chelated iron both stop working above pH 7. EDDHA stays available in alkaline conditions. It is the one product worth being specific about here.
• Add magnesium if older leaves yellow between the veins while new growth is fine — that is magnesium, not iron.
• Lower the pH slowly on outdoor beds and large pots with agricultural sulphur or gypsum, over a season.
• Switch that plant to filtered water if it is a known acid-lover — citrus, gardenia, hibiscus, blueberry.

Salt build-up

A white crust on the mix or the pot rim, brown crisp leaf edges on a plant that is watered correctly, or a sudden decline after months of regular feeding all point to accumulated salt. Scrape off the top centimetre of crusted mix, flush the pot thoroughly twice a week apart, and hold off fertiliser for a month.

6. Reading the symptoms

The one ruleCheck light, watering and roots before you reach for a bottle.

What you see	Most likely	Do this
New leaves yellow, veins stay green	Iron lock-out from alkaline water	Flush, then apply EDDHA chelated iron.
Old leaves yellow between veins, new growth fine	Magnesium shortage	A feed containing magnesium.
Whole plant pale, growth slow and thin	Nitrogen shortage — or not enough light	Check light first, then feed at half strength.
Brown crisp leaf edges, white crust on the mix	Salt build-up	Stop feeding, flush twice, resume at a lower dose.
Lower leaves yellow and soft, sour smell	Overwatering, not hunger	Check the roots. Do not fertilise.
Leaf tips brown in an AC room, soil still damp	Dry air and hard water, not deficiency	Move out of the draught; flush; consider filtered water.
Fine webbing or sticky residue	Pests	Treat the pest — see biological pest control.
Long gaps between leaves, plant leaning	Too little light	Move it, or add a grow light. Fertiliser will not help.

7. A feeding year in Kuwait

The one ruleFeed while the plant is actually growing, and stop when the growth stops.

Period	Indoor plants	Outdoor pots
November – February	Growth slows with the weaker light. Feed monthly at half strength, or pause if nothing is moving.	The main outdoor growing season. Feed every two to three weeks.
March – May	Peak growth. Feed every two weeks at half strength.	Feed every two weeks, then taper as the heat arrives.
June – September	Growth often continues under stable AC and light. Keep feeding, but flush monthly without fail.	Survival mode. Stop or reduce heavily; a stressed plant cannot use it.
October	Restart normal feeding as the heat breaks.	Resume as temperatures drop.

The rule underneath the table: feed the growth you can see, not the month on the calendar.

Continue with the other care guides

• Watering
• Soil & substrates
• Propagation & cuttings
• All plant care

Everything linked here is stocked by NABAT and delivered across Kuwait in 1–4 business days. Free delivery over 10 KD.