How often to fertilize

Feed most houseplants once a month from spring to late summer with a balanced liquid fertilizer at half the strength on the label — and stop in fall and winter. Fertilizer helps a growing plant; it can’t fix a plant that’s struggling with light or water.

More is not better. Over-fertilizing burns roots and causes the same brown tips and yellow leaves people then try to fix with even more fertilizer.

When to feed

Season (US)	What to do
March–April	Start feeding when you see new growth
May–August	Monthly, half strength (every 2 weeks at quarter strength also works)
September	Last feed of the year
October–February	No fertilizer (unless the plant is actively growing under grow lights)

Never feed: a plant with bone-dry soil (water first), a plant you just repotted (wait about a month — fresh mix has nutrients), or a sick plant until you’ve fixed the cause.

Dilution chart

Most liquid houseplant fertilizers say something like “1 teaspoon per quart” or “1 capful per gallon.” Half strength means half of that dose in the same amount of water:

Label says	Full strength	Half strength (recommended)	Quarter strength (every 2 weeks)
1 tsp per quart	1 tsp in 1 quart	½ tsp in 1 quart	¼ tsp in 1 quart
1 tsp per gallon	1 tsp in 1 gallon	½ tsp in 1 gallon	¼ tsp in 1 gallon
1 tbsp per gallon	1 tbsp in 1 gallon	1½ tsp in 1 gallon	¾ tsp in 1 gallon
5 ml per liter	5 ml in 1 liter	2.5 ml in 1 liter	1.25 ml in 1 liter

Always follow your product’s label first; the chart just halves whatever it says. Water the plant normally, then use the diluted fertilizer as the next watering — or apply it to soil that’s already slightly moist.

What N-P-K means

The three numbers on the bottle (like 10-10-10 or 3-1-2) are the percentages of nitrogen (N), phosphorus (P) and potassium (K):

Nutrient	What it does	Good for
Nitrogen (N)	Leaf and stem growth	Foliage plants: pothos, monstera, ferns
Phosphorus (P)	Roots and flowers	Blooming plants: African violet, peace lily
Potassium (K)	Overall strength	Everything

For most houseplants, a balanced or slightly nitrogen-heavy liquid fertilizer labeled for houseplants is all you need. Succulents and cacti do best with a fertilizer made for them, used two or three times a year.

Types of fertilizer

Type	Pros	Cons
Liquid concentrate	Easy to control the dose	Must remember to use it
Slow-release granules	Feed for 3–6 months	Hard to stop if you overdo it; keep away from pets
Fertilizer spikes	Convenient	Concentrated in one spot; can burn nearby roots
Organic (fish emulsion, worm castings)	Gentle	Fish emulsion smells strongly indoors

Signs of too much fertilizer

• White crust on the soil surface or the pot rim
• Brown, crispy leaf tips and edges (other causes of brown tips →)
• Wilting even though the soil is moist
• Lots of weak, floppy new growth

Fix: flush the pot — slowly run water through it for a couple of minutes, about twice the pot’s volume — then skip fertilizer for two months.

Do easy plants need fertilizer at all?

Snake plants, ZZ plants and cast iron plants grow so slowly that once or twice a year is plenty. Fast growers like pothos and monstera use the most, especially in bright light.