Catnip is a tough, mint-family perennial that cats adore and gardeners appreciate for its resilience: it loves sun and heat, tolerates drought and poor soil, and in Zone 9 it will come back year after year with almost no attention. It is also a useful plant in its own right — its leaves make a calming tea, and its flowers attract bees.
The one problem every catnip grower knows: cats. A young plant can be loved to death in a single afternoon by a neighbourhood cat rolling in it. Protect young plants with a wire cloche or a cage until they are established and big enough to cope.
Zone 9 at a glance
USDA Zone 9 covers the warmest parts of the southern United States, including much of Florida, southern Texas, southern Louisiana, southern Arizona and coastal California. Winters are mild, with average winter lows of 20 to 30°F, and the growing season runs nearly all year.
The average last spring frost in Zone 9 is Jan 30–Feb 15, and the average first autumn frost is Dec 1–15. These are USDA zone averages drawn from NOAA frost records, not exact dates for any one garden — always check your local extension service and the forecast before planting tender crops outside.
| Detail | Zone 9 guidance |
|---|---|
| Average winter low | 20 to 30°F |
| Average last spring frost | Jan 30–Feb 15 (average/range) |
| Average first autumn frost | Dec 1–15 (average/range) |
| Days to germination | 7–14 days |
| Days to maturity | 70–90 days |
| Sowing | both |
| 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 9
Sow or plant catnip in Zone 9 in spring, from February through April, or in autumn, from September through November, so roots can establish in mild weather. Seeds germinate in 7–14 days and plants mature in 70–90 days to a first harvest, though catnip really hits its stride in its second year. The average last spring frost is Jan 30–Feb 15 and the average first autumn frost is Dec 1–15 — USDA zone averages, not exact dates, so check your local extension service for your own area. Catnip is hardy and survives Zone 9 winters easily; it may die back in the coldest weeks and regrow vigorously in spring.
Work back from the frost dates rather than from a calendar date: the planting calendar hub gives the Zone 9 picture month by month. The month guides for February in Zone 9 and October in Zone 9 show what else is happening at planting time.
Starting catnip in Zone 9
Start catnip seed indoors in pots or direct-sow into prepared beds — both work. Sow seed on the surface or barely covered, since it needs light to germinate, and keep the soil moist for the 7–14 days it can take to sprout. Seedlings are small and slow at first, so many gardeners buy a plant or take a division from an established clump. Harden indoor-started plants off for a week before setting them out, and space plants 12–18 inches apart. Protect young plants from cats with a wire cage or cloche until they are big enough to cope — this is the single most important step in growing catnip. Once established, a clump can be divided every few years in spring or autumn.
Soil, spacing, sun and water
Catnip needs full sun and well-drained soil with a pH of 6.0–7.0. It tolerates poor, dry soil better than most herbs — in fact, too much water and fertiliser makes soft, floppy growth with a weaker scent. Dig in a little compost before planting, but do not over-feed. Space plants 12–18 inches apart so air can move between them. Water needs are low: water young plants until established, then water only in dry spells. Catnip grows well in pots, which also makes it easy to move out of a cat's reach. A gravel mulch keeps the crown dry.
Companion planting
Good companions for catnip include tomatoes, peppers, marigolds and cabbage, and catnip itself is a useful companion — its scent is said to deter aphids and flea beetles, and its flowers attract bees. Mint is its mint-family cousin, and like mint it can spread, so give catnip its own space — though it is far less aggressive than mint. Our guide to when to plant mint in Zone 9 explains how the two mint-family herbs differ in the garden. Rotate annual crops each year, but catnip is a perennial — choose its spot with the long term in mind. 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, though a healthy plant is rarely troubled. Aphids cluster on young tips — wash them off with water. Spider mites appear in hot, dry weather; keep plants watered at the base. In practice, cats are a bigger problem than insects in Zone 9 — protect young plants with a cage, and accept that an established plant will be rolled in from time to time and will recover.
Harvest and storage
Harvest catnip 70–90 days after sowing, cutting sprigs as needed once plants are established. Pick in the morning, when the oils are strongest, and use leaves fresh or dried — catnip dries well. Cut whole stems just before flowering for the best strength, hang them upside down in a shady, airy place, then strip and store the leaves in a jar. For cats, offer a pinch of dried leaf or a fresh sprig; a little goes a long way. Cut plants back by about a third after flowering to encourage fresh growth, and divide congested clumps every few years.
Frequently asked questions
When should I plant catnip in Zone 9?
Sow or plant in spring (February–April) or autumn (September–November). Seeds germinate in 7–14 days and plants mature in 70–90 days. It is a hardy perennial that survives Zone 9 winters easily.
How do I stop cats destroying my catnip?
Protect young plants with a wire cloche or cage until they are established and big enough to cope. An established plant can handle being rolled in and will regrow.
Is catnip the same as catmint?
They are close relatives, but not the same: catnip is the one cats love most, while catmint is more ornamental and less attractive to cats. Buy named plants to be sure.
Can I grow catnip in a pot?
Yes — catnip grows well in pots, which also makes it easy to move out of a cat's reach. Use well-drained compost and full sun.