Tender Perennial Herb · zones 9–10 · 3 varieties

Sweet Marjoram

Origanum majorana (syn. Majorana hortensis)

Lamiaceae — the same plant family as english lavender, basil, bee balm, mint and 11 more here. Relatives share pests and diseases, which is why rotation plans group by family.

Sweet Marjoram (Origanum majorana (syn. Majorana hortensis)) is a tender perennial herb for USDA zones 9–10. It wants full sun and pH 6–8 soil, with about 0.5–1 in of water weekly. It matures in about 70–90 days from sowing, or 45–60 days from setting out a transplant. Watch for aphids and root rot. Below: its full sourced profile from 9 extension sources, plus a planting calendar timed to your frost dates.

Zones 9–10 — USDA USDA
Sun Full sun
Water Low
Matures 45–60 days — from transplantest from transplant
Mature size 0.7–2 ft
Spacing 12 in
Soil pH 6–8
Frost Tender
When to plant sweet marjoramtypical · zone 6b
Your zone
…or your ZIP, for your real frost dates

Germinating
Seedlings
Growing
Harvest
Dormant

Typical dates for zone 6b — set your zone or ZIP for yours. This calendar assumes the crop is started indoors. Timing is a guide from the crop's sourced growth stages; confirm with your local frost dates and extension before you sow.

Growing sweet marjoramevery fact says where it came from

What we will not put a number on

We do not give a feeding rate for this crop, and that is deliberate rather than a gap. The figures published by extension services are pounds of nitrogen per acre for a production field — they do not convert safely to a raised bed or a pot without knowing your soil test and your fertilizer's analysis, and guessing errs toward burning roots. It is also why every chart you find online disagrees with the next one.

We give watering as a depth per week rather than gallons per plant, because that is how it is actually measured and how the published figures are written. A gallons-per-plant number depends on your spacing, your soil and whether the plant is in a pot — so it would look more precise than it is.

We do not give a direct-sowing date for this crop, and that is a decision rather than a gap. Extension services do publish one, but it is a date for sowing under row covers or cloches — and on its own, next to the fact that frost kills this plant, it reads as an instruction to sow outdoors before your last frost. That is how you lose a crop. Start this one indoors and plant it out once frost is past; the indoor start date is on this page.

Site & soil

Hardiness zones
9–10
This is the winter-survival line, not a growing limit. Colder than zone 9, marjoram is simply grown as an annual and replanted each spring.
Sun
Full sun
Soil pH
6–8
Soil texture
Sandy loam, Loam, Sandy, Well drained
Frost tolerance
Tender

No published figure for the temperature frost starts to hurt it and the temperature that would kill it. We looked — where a number is missing here it is missing from the research, not skipped. The crop’s frost and heat tolerance above still applies.

The plant

Mature height
0.7–2 ft
Mature spread
1–2 ft
Growth rate
Moderateest
Spacing in row
12 in
Between rows
18 in
Planting depth
0–0.25 inest
Container size
2–3 gal — low end is the minimum, high end is better
Support
Self-supportingest
Grown from
Seed, Transplant, Direct sow, Cutting, Division

Water & feeding

Water needs
Low
Water per week
0.5–1 in/wkest
Critical water
Establishmentest
Feeding
Low

Timing & fruiting

Days to maturity
70–90 days from seed · 45–60 days from transplantest
Harvest cues
Flower buds

Planted again for autumn

Set plants out by
early Sep typical · zone 6b

45 days to maturity from setting a plant out — that is what our sources measure for this crop, so this is a date for planting out and not a sowing date, counted back from the first frost above. Not published for anywhere in particular: it is your own frost date and this crop's own figure, which is why it works wherever you are. A days-to-maturity figure is a catalog number for a good season rather than a promise, and a cold month moves it.

Edible parts per source: leaf, flower.

What tends to go wrongmost-cited first
PestsAphidsSpider mitesWhiteflies
DiseasesRoot rotPowdery mildew

Compiled from the extensions cited below. Which ones actually show up depends on your region — your extension's local list is the last word.

⚠ Reported toxicityverbatim from cited sources

Different parts differ — the edible part is the leaf and flower; the notes below flag other parts or preparations.

Petsdogs, cats

Recorded exactly as the source states it — not medical or veterinary advice. If a person or animal may have eaten a toxic part, call Poison Control (1-800-222-1222) or your vet / the ASPCA line (888-426-4435).

All 3 varietiesthe ones with their own page are linked
Variety TypeHabit DaysColorWhat it is known for
Compact Marjoram Compact Compact 45–60 Green Jackson's Nurseries describes this assmaller than most
Hardy Marjoram Hardy Bush 45–60 Green St. Louis Herb Society describes this astakes the cold
Heirloom Sweet Spreading 80–95 Green Botanical Interests describes this asthe flowers are edible · gets by on less water · happy in a pot
Sources9 cited · 7 organizations
  • ASPCA Animal Poison Control Center
  • Missouri Botanical Garden
  • NC State Extension
  • UC Master Gardener Program of Sonoma County (UC ANR)
  • University of Florida IFAS Extension (Pasco County)
  • University of Illinois Extension
  • University of Maryland Extension

We compile bare facts from these university-extension and horticultural sources, never copied prose. 14 of the 20 values on this page carry a citation. The rest are marked est; hover one and it says why — either nobody publishes a figure we could point at, or a person set it and attached no source. Figures vary with climate and seed source; confirm with your local extension before you buy.

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