Lactuca virosa | 'Opium Lettuce'

How to Grow Lactuca virosa from Seed

This guide should get you started with how to grow Lactuca virosa – aka ‘Opium Lettuce’ or ‘Wild Lettuce’ – providing an overview of the subject and covering all the basics required to cultivate this fascinating plant!

As noted on the listing for the Lactuca virosa seed which we sell, it’s a biennial lettuce which is a close relative of Lactuca sativa, the common lettuce’ which we all encounter regularly. A member of the Asteraceae family and a native of Africa, Europe, the UK, the USA and West Asia, Lactuca virosa has found much use as a food (it’s a great source of calcium, omega 3 fatty acids, proteins and vitamins), in homeopathy and as a source of the latex ‘Lactucarium’.

This attractive and rewarding species is quite easy to cultivate anywhere in USDA Hardiness Zones 5-9 and is a great addition to any garden. Essentially, provide moist, well-drained soil (loamy or sandy is best – with a pH level of around seven) and full sun (partial shade if you can’t do better) and you’re golden!

Make sure to sow the seeds on the soil’s surface without covering them, as they really need light to germinate to their full potential. Germination can be improved by soaking the seed for thirty minutes or so before you sow them. This is because the pre-soak stage softens the outer shell of the virosa.

How to Grow Lactuca virosa – Materials:

How to Grow Lactuca virosa – Method:

  1. We recommend sowing Lactuca virosa in containers filled with a sterilised potting soil, such as compost or a mix of earth and peat moss.
  2. Generously and evenly water the soil, but do not allow it to become soggy. From now on, maintain the soil’s moisture at roughly this level – too little water and your seedlings will surely die!
  3. Evenly sow the seeds across the surface of the soil. Remember, they need to be exposed to light in order for germination to occur (taking somewhere between a week to a month to do so).
  4. The optimal germination temperature for Lactuca virosa is approximately 21°C / 70°F. To raise the temperature and moisture levels, we recommend starting by covering the pots with Clingfilm (ensuring that the Clingfilm does not make contact with the seeds, soil or seedlings). Once the first seedlings appear, remove the Clingfilm.
  5. The young plants may be transplanted somewhere frost-free and suitably moist once they have formed a minimum of three healthy sets of leaves. They prefer a location in full sun for ideal growth, but can also tolerate partial shade.
  6. Congratulations, now you know how to grow Lactuca virosa from seed!