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Surface sow
Press tiny seed onto moist compost without burying it. Keep good contact with the surface and avoid washing it into the compost when watering.
Sowing & propagation
Give unusual plants the right start.
A practical reference for when to sow, how deeply to plant, when cold treatment helps, and how to get young plants safely established.
Start here
Sowing calendar & reference
The table gives the quickest answer: find the plant, check whether it needs cold treatment, note the sowing depth and use the timing as your starting point. Where the plant has a catalogue page, click its name to jump straight to that plant’s growing and propagation section.
| Plant | Stratification | Depth | When to sow |
|---|---|---|---|
| Oca | No (tubers) | 5–7 cm | Plant Apr–May |
| Tiger Nuts (Chufa) | No (tubers) | 5–7 cm | Plant Apr–May (after frost) |
| Jerusalem Artichokes | No (tubers) | 10–15 cm | Plant Mar–Apr |
| Ewiger Kohl | No (cuttings) | – | Propagate cuttings Mar–Apr |
| Celtuce | No | 0.5 cm | Sow Apr–May |
| Red Amaranthus | No | 0.5 cm | Sow Apr–May (needs warmth) |
| Purslane | No | Surface/0.5 cm | Sow Apr–May (warmth needed) |
| Thyme | No | 2 mm | Sow Feb–Apr |
| Chickweed | No | Surface/0.5 cm | Sow Feb–Apr (self-seeds after) |
| Victorian Dwarf Pea | No | 3–5 cm | Sow Feb–Apr in trays or direct |
| Yarrow | Optional | 2 mm | Sow Feb–Apr or Aug–Sep |
| Rosemary | No | 5 mm | Sow Feb–Apr with warmth |
| Strawberry Spinach | No | 5 mm | Sow Feb–Apr; direct Apr–Jun |
| Chervil | No | 5 mm | Sow Feb–Mar & Aug–Sep |
| Purple Orach | No | 10 mm | Sow Feb–Mar; direct Apr–Aug |
| English Plantain | No | Surface/0.5 cm | Sow Mar–Apr |
| Lamb’s Quarters | No | Surface/0.5 cm | Sow Mar–Apr |
| Lemon Sorrel | No | 0.5 cm | Sow Mar–Apr |
| Salad Burnet | No | 0.5 cm | Sow Mar–Apr |
| Sculpit | No | 0.5 cm | Sow Mar–Apr |
| Chinese onion chive | No | 10 mm | Sow Mar–Apr |
| Scorzonera | No | 1.5–2 cm | Sow Mar–Apr (direct trays or beds) |
| Salsify | No | 1.5–2 cm | Sow Mar–Apr (direct) |
| Lemon Balm | No | Surface/0.5 cm | Sow Mar–Apr (spreads easily) |
| Babington’s Leek | No (bulbils) | 1–2 cm if seed | Sow Mar–Apr; bulbils Mar |
| Chicory | No | 10 mm | Sow Mar–Apr; direct Apr–Aug |
| Mexican Coriander | No | 5 mm | Sow May–Jun |
| Alexanders | Yes | 1 cm | Sow Oct–Nov, germinates spring |
| Good King Henry | Yes | 1 cm | Sow Oct–Nov, germinates spring |
| Silverweed | Optional | 0.5 cm | Sow Oct–Nov, germinates spring |
| Skirret | Optional | 0.5 cm | Sow Oct–Nov, germinates spring |
| Caucasian Spinach | Yes | 0.5 cm | Sow Oct–Nov, slow may take until Apr–May |
| Angelica | Yes | 0.5 cm | Sow Oct–Nov, sprouts Mar–Apr |
| Lovage | Yes | 0.5 cm | Sow Oct–Nov, sprouts Mar–Apr |
| Meadowsweet | Yes | Surface/light dust | Sow Oct–Nov, sprouts Mar–Apr |
| Sea Kale | Yes | 1.5–2 cm | Sow Oct–Nov, sprouts spring |
| Wild Garlic | No | 10 mm | Sow Nov–Jan |
| Bistort | No | 3 mm | Sow Dec–Feb and sow Feb–Apr |
| Mangelwurzel Ursus Poly | No | 2–3 cm | Sow Apr–May |
| Cinnamon Basil | No | 1–2 mm | Sow May–Jun |
The bit that catches people out
How deeply should seed be sown?
Unusual seeds vary enormously in size. Treat the depth in the table as the plant-specific instruction; these four groups explain what those depths mean in practice.
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Lightly cover
Use only a very fine dusting of compost or vermiculite. The seed should be protected from drying without being buried deeply.
1
Shallow sowing
For the many entries around 0.5–1 cm, make a shallow depression or drill, sow evenly and cover gently before watering.
2+
Deeper sowing
Larger seeds and planting material can sit deeper. Firm the compost or soil back around them so there are no large air gaps.
Cold stratification
When winter is part of germination
Some perennial seeds are adapted to experience winter before they germinate. Others do not need it at all, so cold treatment should be used because the plant calls for it — not as a blanket rule.
Natural winter sowing
Sow at the recommended depth
Use pots, modules or a protected seed bed with free-draining compost.
Leave the sowing exposed to seasonal cold
Keep it outside or in an unheated protected area where it experiences winter conditions without becoming waterlogged.
Do not assume nothing is happening
Some seeds sit apparently dormant for months and only move once conditions change in spring.
Watch moisture as weather warms
Do not let small pots dry completely just as germination begins.
Controlled cold treatment
Start with clean, slightly moist material
The aim is cool and moist, never soaking wet.
Give the seed a cold period
A refrigerator can imitate winter when natural autumn sowing is inconvenient.
Return to normal growing conditions
After the cold period, sow or move the pot to the conditions the species needs for germination.
Be patient with perennial seed
Germination can be staggered. Keep labelled pots longer than you would with quick annual vegetables.
A note about Lovage
Lovage is listed here as not requiring stratification. Normal spring sowing is the preferred starting method; cold treatment is only a fallback if a particular batch proves stubborn.
After sowing
From germination to a sturdy young plant
The exact growing conditions vary by species, but these are the habits that prevent many of the common failures with small batches of unusual seed.
Moist, not saturated
Compost should not repeatedly swing between bone dry and sodden. Fine seed is especially easy to dislodge or bury with heavy watering.
Give seedlings light
Once shoots appear, good light helps keep growth compact. Weak, stretched seedlings are harder to pot on and establish.
Add airflow
Covered trays are useful for retaining moisture during germination, but prolonged stale, humid conditions can encourage mould and damping-off.
Pot on at the right stage
Move seedlings once they are large enough to handle and have started making true leaves, unless the crop is better direct-sown because its roots dislike disturbance.
Harden off gradually
Plants raised under cover need time to adjust to outdoor wind, cooler nights and stronger light before being planted permanently outside.
Label everything
Slow perennial seed can outlast your memory of what was sown. Plant name and sowing date are worth recording from day one.
Troubleshooting
When nothing seems to be happening
Unusual plants do not all behave like fast salad crops. Before throwing a pot away, check which of these situations is most likely.
No germination yet
Check the sowing date, depth and cold requirement first. Perennial seed can be slow or staggered, particularly after autumn/winter sowing.
Seedlings appear then collapse
Reduce excessive moisture and humidity, improve airflow and avoid keeping young seedlings crowded in constantly wet compost.
Seedlings are long and floppy
Increase available light and avoid excessive warmth once germination has occurred. Potting on slightly deeper is suitable for some plants, but it is not a substitute for better light.
Only a few seeds germinated
Do not automatically discard the rest of the sowing. With some perennial species a second wave may appear later, particularly after changing seasonal conditions.
Not everything starts with seed
Other ways to propagate edible plants
Some of the collection is better, faster or necessarily propagated vegetatively. The table identifies the obvious examples; these are the main methods you will encounter.
Cuttings
Used where a plant needs to be copied vegetatively. Ewiger Kohl is the clearest example: a healthy side shoot becomes the next plant.
Division
Mature perennial clumps can often be split into rooted pieces. This is useful for plants such as sorrels, herbs and established crowns.
Tubers & roots
Oca, Jerusalem artichokes and tiger nuts are started from planting material rather than true seed, following the depths and seasons in the table.
Bulbils & offsets
Babington’s Leek can be multiplied from its bulbils or offsets, preserving the perennial plant without relying on seed.
Once it is established
The plant page takes over from here.
This section is deliberately about starting and propagating plants. Once a plant is growing strongly, its individual plant page covers position, soil, ongoing care, harvesting, cooking and nutritional value.
Browse the plant collection