Lettuce flowers are self pollinating, and very rarely cross. But if you plan to save seed from more than one variety you are best to separate them by around 12 foot or plant a tall crop in between the rows or cover the lettuce with fleece/enviromesh.”
Which variety to grow and when to sow –
For varieties that can over-winter with the minimum of protection sow in late summer (Aug/Sept) or for summer varieties sow early Spring to allow plenty of time for the seed to ripen in the same year.
How to grow and save seed –
- Select two or three of the best lettuces from your row, and mark them for seed – stick a label next to them or tie some string round the bases.
- It is important not to save seed from any plants that bolt early, as you want to select for lettuces that not only stand well but have the best growing qualities/attributes.
- The lettuce will grow a long upright stalk, which has the flower heads (seeds) on it. The flowers are yellow.
- Once the lettuces have flowered, the seeds will ripen gradually. Advice is to harvest seed daily to get the maximum yield, shaking into a bag, or to wait until a reasonable number of seeds are ready and then cut the whole plant down. The seed flowers / heads are yellow and will start to dry on the plant to a dull light brown colour. When you touch them they rustle a little in your hand.
- Put the plant (with the seed heads) head first into a bucket or big bag, shaking and rubbing to remove the seeds. If you leave the whole cut plant upside down in the bucket or sack somewhere dry, slightly immature seeds will continue to
ripen over the next few days.
- Most of what you collect in the bucket will be ‘feathers’ and chaff, these are white in appearance To sort the seed, shake it gently in a kitchen sieve. Some seeds will fall through the sieve, with the rest collecting in the bottom. The feathers and chaff will rise to the top, and you can pick them off. I found it best to empty small amounts into a bowl and then rub the seeds / chaff between my fingers and the seed pods opened up fairly easily that way.
- If the seed feels a little damp, dry it further on a plate before labelling and storing. Lettuce seed should keep for around 3 years, provided it is kept cool and dry.