Geraniums — the zonal and ivy types grown in pots and beds everywhere — are one of the most reliable flowers for a Zone 13 garden. Their round flower heads in red, pink, white and salmon bloom for months, their leaves are often scented, and in a frost-free climate they behave as the perennials they truly are, growing into woody shrubs rather than dying back each winter. With winter lows above 60°F, there is no frost to plan around at all.
The challenge in Zone 13 is not cold but wet: geraniums hate soggy soil and humid, still air, so sharp drainage, sun and space matter more than feeding. Give them a pot or raised bed that drains freely, and they will flower generously for years. This guide covers when to plant geraniums in Zone 13, with the soil, spacing, sun, water and care they need. Use the Zone 13 planting calendar to see what else to sow alongside it.
Zone 13 at a glance
USDA Zone 13 has average winter lows of above 60°F and is frost-free year-round — there is no last or first frost date to plan around. Plan by heat and by the wet and dry seasons instead: heat lovers grow year-round, while cool-season crops only succeed in the coolest months. These are zone averages, not promises for any one garden, so check your local extension service for your area.
| Detail | Zone 13 guidance |
|---|---|
| Last / first frost | None — Zone 13 is frost-free year-round |
| Average winter low | above 60°F |
| Days to germination | 7–14 days |
| Days to maturity | 70–90 days |
| Sowing | Start indoors, then transplant as sturdy seedlings |
| Transplanting / planting out | Year-round (frost-free); best results in the planting window above |
| Harvest | Flowers 70–90 days after sowing/planting; pick regularly |
| Sun | full sun |
| Soil pH | 6.0–7.0 |
| Spacing | 12–18 inches |
| Water needs | moderate |
When to plant geraniums in Zone 13
In Zone 13, geraniums can be planted at any time of year because there is no frost — average winter lows are above 60°F and the zone is frost-free, so there is no last or first frost date to plan around. The best establishment comes from plants set out in the cooler months, roughly November to February, when nights are mildest and plants root strongly before the hot season. A hot-season planting is still possible, but water carefully until established and expect softer growth. Geraniums take 70–90 days to maturity, so work back from when you want flowers. Check your local extension service for the best planting windows in your area. Frost dates are zone averages — check your local extension service before you commit to a date.
Because there is no frost to kill them, a geranium planted in the cool season can live for years in Zone 13, growing woodier and larger each season. Keep a note of your planting date and first flowers; after one season you will know exactly which weeks suit geraniums best in your own garden. Take cuttings in the cool season to renew old plants and fill new pots — geraniums root readily from stem cuttings.
Starting geraniums in Zone 13
Geraniums are started indoors, then transplanted as sturdy seedlings — or, more often in Zone 13, grown from nursery plants or cuttings. Sow seed in trays or small pots, keep them warm and give them strong light — seeds germinate in 7–14 days — and grow them on until they have several true leaves. Harden seedlings off for a week before planting out. Cuttings are the faster route: take a healthy stem, let the cut end dry for a day, then push it into free-draining mix and keep it just moist until roots form.
Set plants out on a mild day, in a pot or bed that drains freely, and water them in. Do not plant geraniums deep — set them at the same depth they were growing before — and do not overwater at planting time, since wet soil rots young stems. Pinch out the growing tip once plants have a few sets of leaves to encourage bushy growth and more flowers.
Soil, spacing, sun and water
Geraniums want full sun and lean, well-drained soil with a pH of 6.0–7.0. Do not dig in rich compost or feed heavily before planting: geraniums flower best in poor soil, and rich soil produces leaves at the expense of blooms. Space plants 12–18 inches apart, since crowded geraniums stay damp and invite disease. In Zone 13's heavy rains, drainage is everything — grow geraniums in pots or raised beds with free-draining mix so roots never sit in standing water. Mulch lightly to keep soil moisture even, but keep mulch away from the stems.
Geraniums need moderate water, and they prefer too little to too much: water deeply and less often rather than lightly every day, water at the base in the morning so leaves dry before night, and check the soil a finger's depth down, watering when it feels dry there. In Zone 13's heat, consistent watering matters, but soggy soil kills geraniums faster than drought does. The watering calculator can help you work out a routine that keeps geraniums moist without waterlogging them.
Companion planting
Good companions for geraniums include lavender, marigolds, garlic and chives. Lavender and marigolds draw pollinators and beneficial insects to the bed, while garlic and chives are traditional companions said to deter aphids. The companion planting finder can suggest combinations for your whole bed. Geraniums themselves are useful companions: their scent is said to deter some pests, and they sit well with roses, dahlias and other sunny-bed flowers in pots and borders.
Give geraniums sun and air: their worst problems in Zone 13 come from still, damp air and wet soil, so do not crowd them with tall neighbours. Pots are ideal, since you can move them into sun and shelter them from the heaviest rain. Avoid planting geraniums where the soil stays soggy, and keep them away from plants that need heavy watering, since geraniums prefer to dry out between waterings.
Pests and problems
The common pests and problems to watch for with geraniums are aphids, slugs and cutworms. Aphids cluster on shoot tips and buds and can distort new growth, so check the undersides of leaves weekly and wash small colonies off with a strong jet of water. Slugs chew ragged holes in leaves and young shoots, especially in damp weather, so look under pots and mulch in the morning. Cutworms can sever young stems at soil level, so protect fresh transplants with a simple collar pushed into the soil around each stem.
In Zone 13's year-round warmth, pests never get a winter break, so check plants weekly rather than waiting for damage to show. Good air flow helps: space plants properly, avoid overhead watering late in the day, and remove spent flowers and damaged leaves promptly. Stem rot is the main disease in wet conditions — water at the base, use free-draining mix, and never let pots sit in saucers of water.
Harvest and storage
Geraniums flower 70–90 days after sowing or planting, and deadheading keeps them coming. Remove spent flower heads every few days, snapping the whole stalk off at its base, and the plant will keep producing fresh blooms. Cut flowers in the cool of the morning for small posies, choosing heads that have just opened. In Zone 13, a well-cared-for geranium can flower for months, slowing only in the hottest, wettest weeks and picking up again as temperatures ease.
For the vase, cut stems in the morning, strip the lower leaves, and put stems straight into cool water. Scented-leaf geraniums can be used to flavour teas and baking, and their leaves are lovely in potpourri — but only use leaves from plants you have grown yourself without sprays. Take cuttings in the cool season to renew old, woody plants: a fresh cutting flowers sooner than an old shrub, and you can keep your favourite colours going for years.
Making the most of Zone 13
Zone 13's advantage is time: with no frost, you can grow geraniums as long-lived perennials rather than summer annuals. The trick is to plant for the cooler months, give them sharp drainage, and keep a simple notebook of what you planted and when it flowered — after one season you will have a record far more useful than any general guide. Related reading: dahlias share the same sunny-bed habits, and January in Zone 13 is a great month to plant. Lavender in Zone 13 is a classic companion that thrives in the same sunny spot. Related reading: Dahlias in Zone 13 share the same habits, and January in Zone 13 is a great month to plant. For a planting plan tailored to your postcode, try the planting calendar by zip.
Frequently asked questions
When should I plant geraniums in Zone 13?
Geraniums can be planted year-round in frost-free Zone 13, but the best establishment comes from planting in the cooler months, roughly November to February. Average winter lows are above 60°F, so there is no last frost date to count back from. Check your local extension service — these are zone averages, not exact dates for your garden.
How long do geraniums take to grow in Zone 13?
Seeds germinate in 7–14 days, and plants flower 70–90 days after sowing or planting. In Zone 13, a geranium planted in the cool season can live for years, growing woodier and larger each season.
Can I grow geraniums all year in Zone 13?
Yes — Zone 13 is frost-free, so geraniums grow year-round as perennials. Flowering is heaviest in the cooler months, and plants need sharp drainage and sun through the hot, wet season.
What soil and spacing do geraniums need in Zone 13?
Geraniums need full sun and soil pH 6.0–7.0, spaced 12–18 inches apart. They flower best in lean, free-draining soil — grow them in pots or raised beds, water at the base, and test your soil through your local extension service.
Why are my geranium stems rotting in Zone 13?
Stem rot comes from wet soil and still, humid air. Use free-draining mix, never let pots sit in saucers of water, water at the base in the morning, and give plants sun and space so leaves dry quickly.