Jekka's tips on maintaining, growing and caring for your herb plants in autumn & early winter

Jekka's tips on maintaining, growing and caring for your herb plants in autumn & early winter

Autumn, early winter, is the time to put your feet up, relax and look back on the year as the plants go into hibernation.

That is one approach, needless to say, gardening jobs never stop and there is always something to be doing. Building on our previous blog about 'Sowing your winter culinary herbs' we now look at what herb maintenance activities you can be doing to ensure a herb filled autumn and winter as well as a successful year ahead.

In the late autumn you should clear the garden, remove annual weeds and then mulch around established shrub herbs with well-rotted compost or leaf mould.  If you are surrounded by trees that shed their leaves in winter, check that they have not fallen on any low growing herbs, especially thymes or oreganos, because if left these herbs will slowly rot under the damp leaves.

Cut back, this should be the final pruning of a few outstanding plants. For example: mints and lemon balm.

Dig-up and remove any of the annuals that have finished. For example: dill, coriander, borage, summer savory, and sweet marjoram as well as the second year biennials: chervil and parsley especially if they have run to seed.  

Lift, divide and bring in for the winter. For example: you can force roots of tarragon and mint  for use through the winter.  Herbs such as lovage, sorrel,  chives, lemon balm, bergamot, hardy oreganos can be divided and either replanted or potted up for replanting in the spring.

Plants in containers. At this time of year you should start reducing the amount of water you give container herbs as they go into hibernation that means they require little water. If you are leaving tender herbs outside in containers, it is a good idea to position them against a wall as this will not only protect them from the rain, they will also gain the residual heat from the wall.  If they are in terracotta’s it is worth wrapping the containers in sacking.  Also, for those you have brought inside, be careful not to over-water as this often causes mould and botrytis.

Final seed collection. If you have not done this already, collect any remaining seeds on a dry day and store in paper bags or large old envelopes in a dry place. We dry our seed heads, like lovage, fennel or angelica, on paper in the seed store. Alternatively you can hang them upside down with a paper bag tied lightly around the seed heads, so that the seeds dry and fall into the bag.

Fresh herbs available for use in the kitchen. At this time of year there is still a wide range of fresh herbs that one can pick in the garden. These include bay, rosemary, parsley, thyme, sage, hyssop, oregano, chervil, winter purslane, salad burnet, coriander. If you have sown it in September, mustard, mizuna and, if you have forced it, mint. You can also make vinegars, pesto, tapenades, herb butters, sauces and soups as well as preserves with your herbs, see our herb-based recipes for some ideas.

Jekka's herb specific maintenance tips:

  • Sage, Oregano, and Thyme - Hopefully you have already cut back after flowering.  However note that some, like pineapple sage, often flower late into winter.  To save these getting mildew remove the flowers as they fade, do not cut back as the plants will not heal and this can lead to damage in wet conditions.  In the UK climate, hardy sage, oregano and thyme will be fine outside unprotected as they can tolerate temperatures as low as -10C as long as they are growing in a well-drained soil.  
  • Mint - We have somewhere in the region of 40 different mints in Jekka's Herbetum. They are planted in pots to avoid them spreading and mixing, which both makes them manageable but also keeps their uniqueness and individual flavours. If your mint plants are in pots you will need to lift and divide or plant them into bigger pots annually. It is also the time to take mint cuttings from the rhizomes to propagate new plants. You can also put a small amount of root into a seed tray, bring in and force for Christmas.
  • Rosemary - Rosemary is a robust perennial evergreen mediterranean herb that will survive outdoors when grown in a free draining soil.  It will tolerate temperatures of -10C and will survive most UK winters, even if we have snow. 
  • Lavender - With the changing climate we now prune our lavenders " one 8th in the 8th month", which translates to cutting back an 8th of the new growth in August. Remember not to cut back into the old  wood where there is no new shoots as it will not regenerate. This enables the plant to form a tight shape that protects it from the now frequent heavy downpours that we have. Also ensure your soil is well drained as it is the dampness, more than cold, that is responsible for killing lavender plants in the winter.

    It is time to put your herbs into hibernation mode and here is a summary of Jekka's autumn, early winter, action list:

    • Reduce the watering of herbs grown in containers.
    • Protect plants like lemon verbena, bay and myrtles in outside containers with fleece and, if possible, move them to a south-facing wall for the winter.
    • Sow your last winter herbs: parsley, chervil and winter purslane.
    • Take root cuttings of horseradish, tarragon and mint.
    • Divide herbs like, oregano, lovage, sorrel, chives, lemon balm, salad burnet, alecost and bergamot.
    • Collect and dry your seeds.
    • Clean your tools ready for next year or put some new tools on your Christmas List! See our gardening tools here.

    Then perhaps you can put your feet up with a herbal infusion and think of warmer days while planning next years’ sowing and growing. Check out Jekka’s blog, videosbooks and master classes for further inspiration and ensure you subscribe to our newsletter to find out what we have in store for next year.