Summer is prime time for the gardener and your herb garden. You can reap the benefits of your hard work during the spring and enjoy the plants that are now becoming established.
This blog is part of the ‘Jekka’s Seasonal Tips’ series that includes early spring, late spring and autumn & winter. Together they form the basis of Jekka’s guide on how to grow herbs.
Summer can also be a challenging period in the garden where the weather can vary from heat waves to down pours and this summer is no exception. Therefore, as with any other season, you have to be on your toes. One of the most important things you can do is ensure your plants have enough water and feed; particularly if they are in containers.
Seasonal tasks in the Herb Garden and for Containers
- Trim and/or cut back your perennial herbs
After they have flowered you should cut back your perennials to remove the dead flowers and to maintain their shape, especially plants in the Lamiaceae family, that includes both Lavender and Thyme (check out our Lavender blog on our website for more tips on how and when to prune Lavender). As soon as Mint starts to go over or get mildew cut back hard, this will promote a second flush of leaves that can be used until the first hard frosts. Other plants you might consider trimming or clipping are Box and Cotton Lavender.
- Give extra care to your herb plants in containers
In periods of high wind and temperatures, keep an eye on your containers and ensure they do not dry out. Some days you might need to water more than once if it gets really warm and it’s best to water in the morning so the plants have the water when they need it throughout the day.
- Feed your herbs
Ensure you feed weekly with a liquid fertiliser, we use Maxicrop liquid seaweed. For the more established herbs in containers it might be beneficial to pot up into bigger pots or top dress with new compost.
- Water your herbs
If this is the plants first summer in the garden and the plants are not yet fully established it is important to make sure they do not dry out, so water regularly. Once established, many plants are tolerant of drought; however, keep an eye out on leafy plants such as mint, parsley and comfrey that all need water to flourish.
Jekka’s top watering tip: don’t water basil after midday, water Basil before lunch so he does not go to bed wet when the night temperature falls below 15C.
Propagation & growing herbs in summer
- Time to take cuttings
Continuing on with the spring activities, you can take semi ripe wood cuttings of Southernwood, Lemon Verbena, Sages, Myrtles Lavenders and Thymes. Choose non flowering material. Check out Jekka’s video on taking cuttings for the best technique.
- Sow herbs from seeds.
The ground is now warm enough to sow seeds outside. Jekka’s list of herbs that you could sow are:
- Angelica (Angleica archangelica) (Use only fresh seed; germination at this time of the year is about 10 days. If you sow in the spring you will need to stratify the seeds to awake dormancy.)
- Chives (Allium schoenoprasum)
- Chervil (Anthriscus cerefolium)
- Coriander (Coriandrum sativum)
- Dill (Anethum graveolens)
- Parsley (Petroselinum crispum)
- Harvest herb seeds
Later in the summer, as the season wanes, the biennials and annuals will start to go over and it is time to start thinking about next year and ensure you collect and store seeds.
Here at Jekka’s Herb Farm we collect as many varieties of herb seed as possible. During the summer we are continually checking to see if the seeds are ripe. The signal to start collecting is when the seeds start to naturally drop. Collect on a hot dry day, make sure you have some paper bags or envelopes and a pen so you can write the name of the seed onto the packet. We store seeds in a dark airy room until they are dry. Once fully dry we clean them and then file them in paper envelopes and then store them in a filing cabinet in an unheated shed with a dehumidifier. For home use, choose a box with a fitting lid, then store it either in a dark shed, the garage or in the lettuce compartment of the refrigerator. Not in the greenhouse.
Seeds we have recently harvested are:
- Alliums (early flowering) – Read Jekka’s Blog “All About Alliums”
- Angelica (Angleica archangelica)
- Buckler Leaf Sorrel (Rumex scutatus)
- Calamint (Calamintha Grandiflora)
- Caraway (Carum carvi)
- Jekka’s Peony Poppy
- Pot Marigold (Calendula officinalis)
- Painted Sage (Salvia Viridis)
- Sea Kale (Crambe maritimum)
- St John’s Wort (Hypericum perforatum)
- Woad (Istatis tinctorial)
Using and preserving herbs
- Use fresh herbs in the kitchen
There continues to be a good supply of herbs for the kitchen from the spring and the majority, if not all, of the culinary herbs in your garden can be harvested now. As plants go to flower don’t forget these are also edible and can add more flavour, depth and colour to meals. Try eating the flowers of Dill, Chervil, Coriander, Sage and Savory.
Jekka’s top culinary tip: chop herbal flowers through butter and serve on warm pitta.
- Start preserving
Now is a great time to start thinking of the colder months to come and the harvesting of herbs for preservation. You could make Tarragon vinegar (see our ‘All About Tarragon’ blog) or dry herbs such as sage, lemon balm or lemon verbena for herbal and oil infusions. You can also freeze herbs in ice cube trays for later use, herbs that freeze well include chives and mint.
Jekka's summer action list
- Deadhead flowering plants regularly
- Water, water, water! - particularly containers and new plants
- Collect seed from flowering herbs, dry and store for next spring.
- Feed container herbs – we recommend Maxicrop liquid seaweed
- Do not remove the shade from greenhouse until autumn has set in, it prevents the young plants from sun scorch.
- Sow seeds for winter herbs and for use next year.
- Take cuttings for next year
For more information, you can sign up to our newsletter or follow us on Instagram @jekkasherbfarm for more tips. When we are able, we will be running our Master Classes and Herb Experiences for more hands on techniques (see our events calendar).
Herb plants and seeds are available from Jekka’s and you can organise a collection from our herb farm in South Gloucestershire or at one of our Open Days or Herb Experiences. Please see our 'Looking Good List' for availability and use our webform or email your list directly to us (sales@jekkas.com). We no longer offer a mail order service for our plants.