Free Growli tool
When (and what size) to
repot your plant.
Pick your plant, enter your current pot diameter, and tell us how long since the last repot. The calculator returns a repot-now / not-yet verdict, the recommended next pot size (typically 1 to 2 inches larger), the right soil mix, and drainage requirements for 30 popular houseplants. No signup required.
Your plant + pot
Verdict
Repot now
Your monstera is a fast-grower and is past the typical 12 to 18 months repot interval. Move it up to a 8-inch (20 cm) pot this season.
Recommended next pot
8 in / 20 cm
Step up by 2 inches in diameter — going larger traps moisture roots cannot use, which is the most common cause of post-repot root rot.
Soil mix
Aroid mix
Chunky blend of bark, perlite, and a small amount of potting soil. Mimics the loose, airy root zone aroids grow in on the forest floor.
Drainage
Pick a pot with drainage holes. If your decorative pot has no holes, use it as a cachepot and keep the plant in a smaller plastic nursery pot inside.
How the calculator decides
Each of the 30 supported species is tagged with a growth-rate band: slow (snake plant, ZZ plant, cacti, jade), medium (pothos, peace lily, spider plant, philodendron), or fast (fiddle leaf fig, rubber plant, dracaena, monstera in good light). The repot interval comes from that band:
- Slow: repot every 2 to 3 years.
- Medium: repot every 18 to 24 months.
- Fast: repot every 12 to 18 months — sooner if roots are circling the drainage holes.
Next pot size. Standard advice is to step up by 1 to 2 inches (2.5 to 5 cm) in diameter. Going larger traps moisture roots cannot use and is the #1 cause of post-repot root rot. The calculator picks the upper end (2 inches) for fast growers and the lower end (1 inch) for slow growers.
Soil mix. Tropicals want a peat- or coco-based mix with perlite. Succulents and cacti want a gritty cactus mix. Orchids want bark chips, not soil. African violets prefer a light peat blend. The output card shows the right mix for the species you picked.
Frequently asked questions
How much bigger should a new pot be than the old one?
Step up by 1 to 2 inches (2.5 to 5 cm) in diameter for most houseplants. Going larger than that traps moisture around the roots that the plant cannot use, which leads to root rot. The only exception is fast growers like fiddle leaf figs and rubber plants, which can handle a 2 to 3 inch step up.
How do I know when a plant needs repotting?
Three reliable signs: roots growing out the drainage holes, water running straight through without being absorbed, and the plant becoming top-heavy or tipping over. Slow growers (snake plant, ZZ plant, cacti) only need repotting every 2 to 3 years. Fast growers may need it every 12 to 18 months.
What soil mix should I use?
It depends on the species. Standard tropical houseplants (monstera, pothos, peace lily) want a peat- or coco-based mix with perlite for drainage. Succulents and cacti need a gritty cactus mix with extra perlite or pumice. Orchids need bark chips, not soil. African violets prefer a fluffy peat-light mix. The calculator surfaces the right mix per species.
Should the new pot have drainage holes?
Yes — drainage holes are non-negotiable for almost every houseplant. They let excess water escape so roots can breathe. If you love a decorative pot without holes, use it as a cachepot and put a smaller plastic nursery pot inside.
Can I repot a plant at any time of year?
You can, but spring and early summer are best — that is when the plant is actively growing and recovers fastest. Avoid repotting a plant that is flowering or stressed (heatwave, recent move, pest treatment). The one exception: if a plant is suffering from root rot, repot immediately regardless of season.
How is this different from the Growli app?
The calculator gives you a one-shot verdict per plant. The Growli app remembers each of your plants, tracks when you last repotted, and reminds you when each one is due — adjusted for actual growth rate from photos you upload.