Catnip is the herb your cat already knows about: a mint-family plant whose leaves drive most cats into a happy frenzy, and a useful tea herb and bee plant for everyone else. In Zone 12 it grows easily as a perennial, but like all mints it spreads — plant it in a pot or a contained spot, or it will take over the bed.
Like every crop in the tropics, catnip rewards gardeners who work with Zone 12's seasons — the cooler, drier months and the hot, wet months — rather than against them. The planting calendar hub gives the Zone 12 picture month by month, and our guide to when to plant catnip in Zone 11 shows how the timing shifts in a cooler zone.
Zone 12 at a glance
USDA Zone 12 covers the warmest, most tropical parts of the United States — Hawaii, Puerto Rico, Guam and the U.S. Virgin Islands. Winters are warm, with average winter lows of 50 to 60°F, and the growing season never really ends.
Zone 12 is frost-free year-round: there is no average last spring frost and no average first autumn frost. That means you plant by heat and by the wet and dry seasons, not by frost dates. These are USDA zone averages, not exact figures for any one garden — always check your local extension service and the forecast before planting.
| Detail | Zone 12 guidance |
|---|---|
| Average winter low | 50 to 60°F |
| Average last spring frost | Frost-free (no frost dates) |
| Average first autumn frost | Frost-free (no frost dates) |
| Days to germination | 7–14 days |
| Days to maturity | 70–90 days |
| Sowing | start indoors or direct sow |
| Sun | full sun |
| Soil pH | 6.0–7.0 |
| Spacing | 12–18 inches |
| Water needs | low |
| Cold tolerance | hardy |
When to plant catnip in Zone 12
Plant catnip in Zone 12 in spring or autumn, when the weather is warm but not at its hottest, so young plants establish without stress. Because Zone 12 is frost-free, with winter lows of 50 to 60°F, there is no frost date to wait for — catnip grows year-round here, slowing only slightly in the coolest months. Seed germinates in 7–14 days and plants reach harvest size in 70–90 days. Check your local extension service for the best local planting window. See the Zone 12 October planting guide for what else to plant that month.
Starting catnip in Zone 12
Start catnip indoors from seed or direct sow it, since it is easy either way. Seed is small, so sow it shallowly and keep it moist until germination in 7–14 days. Transplant seedlings out when they are sturdy, spacing plants 12–18 inches apart. The most important decision is where: catnip spreads by seed and by runners, so a pot, a raised bed of its own, or a spot you are happy to let it colonise is the wise choice.
Soil, spacing, sun and water
Catnip needs full sun and ordinary, well-drained soil with a pH of 6.0–7.0. It tolerates poor, dry soil better than rich, wet soil — too much water or fertiliser makes soft, floppy growth with weaker scent. Water needs are low: water young plants until established, then water only in dry spells. In Zone 12's wet season, sharp drainage matters more than feeding, and a pot with gritty mix is often the best home for it.
Companion planting
Good companions for catnip include tomatoes, peppers, marigolds and cabbage. Its strong scent is said to deter aphids and other pests, and it is traditionally planted near vegetables for that reason — but keep it contained, since it will crowd out neighbours if left loose. The companion planting finder can suggest combinations for your whole bed.
Pests and problems
The common pests to watch for with catnip are aphids, spider mites and whiteflies. Aphids cluster on soft new growth — wash them off with water. Spider mites thrive in hot, dry air and show as fine webbing and speckled leaves; mist the plant and improve air flow. Whiteflies cloud up when the plant is disturbed; yellow sticky traps help. In Zone 12 the biggest pest is often the neighbourhood cats, which will roll in the plant — protect young plants with a wire cloche until they are established.
Harvest and storage
Harvest catnip 70–90 days after sowing, once plants are bushy. Pick leaves and flowering tops in the morning, when the aromatic oils are strongest, and use them fresh or dried. Dry bunches in a warm, airy spot out of direct sun, then crumble the leaves into a jar for tea or cat toys. Cut plants back by a third after flowering to encourage a second flush, and deadhead if you do not want it to self-seed everywhere. Use the herb drying calculator to work out drying times for your harvest.
Catnip for cats — and for the garden
About two out of three cats respond to catnip, rolling, rubbing and purring in the leaves. The effect comes from nepetalactone in the leaves and lasts ten minutes or so, after which the cat loses interest for a while. Fresh leaves are stronger than dried, so pick a sprig and offer it directly, or dry leaves and sew them into a small cloth toy.
For the garden, catnip is more than a cat toy: its flowers attract bees and beneficial insects, its scent is said to repel aphids and squash bugs, and a cup of catnip tea is a traditional remedy for sleeplessness. Grow one plant for the cats and one for yourself — in separate pots, if you want either to survive.
For a related crop, see our guide to when to plant borage in Zone 12.
Frequently asked questions
When should I plant catnip in Zone 12?
Plant in spring or autumn, when the weather is warm but not at its hottest. Seed germinates in 7–14 days and plants reach harvest size in 70–90 days, and catnip grows year-round in frost-free Zone 12.
Will catnip take over my garden?
It can — catnip spreads by seed and runners like other mints. Grow it in a pot or a contained bed, and deadhead before it sets seed if you want to limit its spread.
Do all cats like catnip?
No — about two out of three cats respond to it. Kittens and some older cats may ignore it entirely, and the effect usually lasts only about ten minutes.
Can people use catnip?
Yes — catnip leaves make a mild, minty tea traditionally used to help with sleep. Use dried leaves, steeped like any herbal tea.