St John's wort

St John's wort: plant 40 cm (16 in) apart in the row and 50 cm (20 in) between rows, 1 per square. No known bad neighbours.

Key facts

Spacing in the row	40 cm (16 in)
Between rows	50 cm (20 in)
In a 30 cm (1 ft) square	1 per square
Sun	Full sun, 6–8 hours a day
Root depth	25 cm (10 in)
Height when grown	60 cm (24 in)
Crop rotation group	Herbs, flowers and perennials
Support	None needed

How it is started	Started in trays, by dividing a clump
Seeds per hole	3
Plants kept after thinning	1
Sowing depth	0.1 cm (0 in)
Soil temperature	from 13 °C, best 18–24 °C
Days to emerge	14–30 days
Light while germinating	Needs light, barely cover
Before sowing	Chill moist for a few weeks
When to plant	Indoors 6 weeks before the last frost; outdoors after the last frost; soil at least 12 °C

After emergence	16–22 °C; take the cover off as soon as they show
Pricking out	at 2 true leaves
Takes transplanting	Easily
Hardening off	7–10 days
Life cycle	Perennial
Cold tolerance	Takes a light frost → hardy, takes hard frost
Soil	Light, sandy, free draining, pH 6–7.5
In a pot	5 L, 20 cm (7.9 in)
Watering	Water when the soil is dry two fingers down
Feeding	Little
Support and training	None needed; pinch the tips

Open the free planner, drop St John's wort onto a bed and see how many plants fit.

Plant out	Apr–May
Harvest	Jun–Aug

My country Last spring frost where I live

Give the date once and this page, the sowing calendar and the planner all follow it.

Months for a temperate climate: about a month later in the north and a month earlier in the south. Give your own last frost date for exact dates.

Crops that need about the same room and care, from another family.

Crops that still have time to grow on the same spot once it is lifted, from another rotation group.