Saving herb seeds

Seeds from the Secret Garden's fennel plant against the sky.

The fennel plant in the Secret Garden is now over seven feet tall, throwing out aromatic feathery leaves, delicate flowerheads which then produce a multitude of pungent fennel seeds. This is a fennel plant (Foeniculum vulgare), grown as a herb rather than the variety grown for its bulbous root (Florence fennel or Foeniculum vulgare "Azoricum"). The leaf fronds are used for flavouring fish and salads, the flowers in pickles, and the seeds in spiced foods, stuffings, and sauces.

Herb fennel is a perennial plant. These impressive high stems will die back over the winter, but you'll usually see bushy feathery regrowth at the base of the main stalks starting in autumn which will come back strongly in spring. It is happiest in a light, well-drained soil in a sunny sheltered site.

Having successfully raised your herb plants they will eventually set seed if you leave the flowerheads on the plant.  Herbs like coriander, dill, lovage and fennel have edible seeds as well as leaves. In using the seed in the kitchen as well as the leaves - and also the flowers, see our post here - you will be getting maximum value from your plants. The seeds from your own herbs will also have an unmatched freshness and concentration of flavour.

Even if you don’t eat them, you can save the seeds to grow next year. This is one way to ensure that over the generations you will raise plants which is perfectly adapted for your conditions. 

Let the plant grow and flower, after which it will set seed. Cut the seedheads before they fall to the ground. You might want to put the whole seedhead in a paper bag and snip the stem to ensure no seed is wasted. 

Next, remove the chaff – the bits of stalk and seedcase. Put the seed in a jar and seal. Label it carefully. 

Store seed somewhere cool, dark and dry, and, for culinary use, try to eat them within three months. If you're saving the seed to sow again next year, keep them in a paper bag or envelope (not plastic or polythene), rather than  a jar, again somewhere cool and dark.

For detailed advice on saving seeds for a number of vegetable plants, the best place I've found on the web is Real Seeds which has detailed and authoritative advice.