Calendula, often called pot marigold, brings cheerful orange and yellow flowers to a Zone 13 garden in the months when little else is flowering. It is a cool-season annual that loves mild weather, and with winter lows above 60°F and no frost at all, Zone 13 gives it a short, bright season in the coolest months rather than a long one. That season is generous: calendula flowers for weeks if you deadhead it, and it self-seeds freely.
Calendula is also a working plant, not just a pretty one. Its flowers attract pollinators and beneficial insects, its petals are edible, and it has a long history of use in skin preparations — though you should never use it medicinally without proper advice. This guide covers when to plant calendula in Zone 13, with the soil, spacing, sun, water and care it needs. 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 | 45–60 days |
| Sowing | Start indoors or direct sow |
| Transplanting / planting out | Coolest months only; best results in the planting window above |
| Harvest | Flowers 45–60 days after sowing/planting; pick regularly |
| Sun | full sun |
| Soil pH | 6.0–7.0 |
| Spacing | 9–12 inches |
| Water needs | moderate |
When to plant calendula in Zone 13
In Zone 13, plant calendula in the coolest months, roughly November to February, when nights are at their mildest. There is no last or first frost date to plan around — Zone 13 is frost-free year-round with winter lows above 60°F — so work from the calendar and the cool season instead. Sow seed in the months before that window so seedlings are ready to set out as the coolest weather arrives, or sow direct in the bed in November. A planting made in the hot season will struggle: plants stretch, flower sparsely and are quickly finished by heat. Calendula takes 45–60 days to maturity, so a November sowing can flower early in the cool season. 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.
Keep a note of your sowing date and first flowers; after one season you will know exactly which weeks suit calendula best in your own garden. Succession sow a second batch a few weeks after the first to stretch the display, but do not sow after the cool season has passed — late plants rarely flower well before the heat arrives. Calendula self-seeds freely, so let a few flowers go to seed and seedlings will appear on their own next cool season.
Starting calendula in Zone 13
Calendula can be started indoors or sown direct, and in Zone 13 direct sowing is the easiest route. Sow seed thinly in the bed, cover lightly, and keep the soil moist until seedlings appear — seeds germinate in 7–14 days. Thin seedlings to the final spacing once they are big enough to handle. If you start indoors, sow in trays or small pots, keep them in a cool, bright spot, and harden seedlings off for a week before planting out.
Calendula is a tough, forgiving plant: it tolerates poor soil, light shade and a missed watering better than most flowers. That toughness makes it a good first flower for a new Zone 13 gardener. Water seedlings in well at planting time and mulch lightly around the base to keep the soil cool and evenly moist through the cool season.
Soil, spacing, sun and water
Calendula wants full sun and well-drained soil with a pH of 6.0–7.0. Dig in well-rotted compost before planting and space plants 9–12 inches apart, since crowded plants stay damp and invite disease. Unlike cosmos, calendula appreciates reasonably fertile soil, but do not overfeed — too much nitrogen produces leaves at the expense of flowers. Mulch lightly to keep soil moisture even, but keep mulch away from the stems.
Calendula needs moderate water: 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, even a cool-season plant in full sun dries out fast, so do not let the soil dry out while plants are in flower. The watering calculator can help you work out a routine that keeps calendula moist without waterlogging it.
Companion planting
Good companions for calendula 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. Calendula itself is a famous companion: its flowers attract beneficial insects, and it is often planted beside tomatoes and other vegetables to draw pollinators and confuse pests.
Give calendula the front of a border or a sunny bed where its bright flowers can be seen, and let it self-seed at the edges of the vegetable garden, where it does its best work. Avoid planting it where the soil stays soggy, and keep it away from plants that need very dry soil, since calendula likes steady moisture. A mixed cool-season bed of calendula, pansies and snapdragons makes a bright display in the months when little else is flowering.
Pests and problems
The common pests and problems to watch for with calendula are aphids, slugs and thrips. 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. Thrips rasp the petals and leave silvery streaks on flowers — remove badly marked blooms and keep plants well watered, since stressed plants suffer more.
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. Powdery mildew can appear in humid weather — water at the base, mulch, and give plants room to breathe rather than crowding them.
Harvest and storage
Calendula flowers 45–60 days after sowing, and picking keeps them coming. Deadhead spent flowers every few days, pinching them off just above a leaf, and the plant puts its energy into new buds instead of seed. Cut flowers in the cool of the morning for small posies, and pick petals for salads and garnishes — only use petals from plants you have grown yourself without sprays. In the heat of the hottest months, flowering slows and then stops, so enjoy the display while it lasts and compost plants once they are spent.
For the vase, cut stems in the morning, strip the lower leaves, and put stems straight into cool water. Let a few flowers go to seed at the end of the display if you want volunteers next cool season — calendula self-seeds freely in a frost-free climate, and seedlings will appear on their own in the bed. Dry petals for potpourri by spreading them thinly in a cool, airy place out of direct sun.
Making the most of Zone 13
Zone 13's advantage is time, but calendula is a cool-season exception: it gives you a bright, useful season in the coolest months and then makes way for heat-lovers. The trick is to sow for the cool season, deadhead constantly, and keep a simple notebook of what you sowed and when it flowered — after one season you will have a record far more useful than any general guide. Related reading: pansies share the same cool-season habits, and January in Zone 13 is a great month to plant. Marigolds in Zone 13 are a warm-season companion that takes over the bed once calendula finishes. Related reading: Pansies 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 calendula in Zone 13?
Plant calendula in the coolest months, roughly November to February, when nights are at their mildest. Zone 13 is frost-free with winter lows 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 does calendula take to grow in Zone 13?
Seeds germinate in 7–14 days, and plants flower 45–60 days after sowing. In Zone 13, sow in time for the coolest months so flowers arrive before the hot season, since heat shortens the display.
Can I grow calendula all year in Zone 13?
No — calendula is a cool-season flower and fades fast in Zone 13 heat. Grow it as a cool-season annual from November to February, then replace it with heat-lovers such as cosmos or nasturtiums for the hot months.
What soil and spacing does calendula need in Zone 13?
Calendula needs full sun and soil pH 6.0–7.0, spaced 9–12 inches apart. Dig in well-rotted compost, water at the base, mulch lightly, and test your soil through your local extension service.
Are calendula flowers edible?
Yes — calendula petals are edible and often used in salads and as a garnish. Only eat petals from plants you have grown yourself without sprays, and do not use calendula medicinally without proper advice.