Rosemary and lavender will thrive when a common food scrap is added to the soil. Woody herbs like rosemary, thyme, and lavender require a different feeding approach compared to leafy herbs, and one food scrap is the perfect ingredient to help them flourish.
Why Woody Herbs Need Special Care
Herbs are easy to grow and can even thrive in pots on a windowsill, yet many gardeners make the crucial mistake of feeding them all the same way. Leafy herbs such as basil, mint, and parsley benefit from a generous dose of nitrogen in late spring and early summer, as it accelerates growth and enhances flavour. However, woody herbs including rosemary, thyme, and lavender require a considerably different approach to fertilisation. Nitrogen encourages leaf growth, but applying it to Mediterranean herbs can actually reduce their flavour, leaving the plants weaker and more susceptible to disease.
If leafy herbs are what you are growing, they should be fed once a month with a nitrogen-rich fertiliser, or you could opt for homemade alternatives such as teabags or used coffee grounds. For hardier woody herbs like lavender, rosemary, and thyme, a light feed in spring is sufficient to give them a boost.
Eggshells: The Natural Solution
Herbalist and Simply Beyond Herbs founder Vladka Merva has revealed a straightforward method for feeding woody herbs using crushed eggshells. She explained that eggshells are a great source of calcium that seeps into the soil as you water it. Calcium is important for plant growth and nutrition, as well as for maintaining chemical balance in the soil and improving water penetration.
Boosting your woody herbs with calcium not only strengthens their general health but also promotes root growth, safeguarding them from typical issues such as blossom end rot. This extra nutrient can also increase soil alkalinity, a characteristic especially preferred by herb types including lavender and rosemary.
Additionally, eggshells, with their naturally sharp texture, act as an effective barrier against pests that might target kitchen-grown herbs, which are often vulnerable to insects indoors. Vladka noted that crushed eggshells serve as pest control, deterring slugs, cutworms, and other insects.
How to Use Eggshells for Woody Herbs
First, leave the eggshells to dry completely in a warm spot, then crush them with a rolling pin to speed up decomposition once mixed into the soil. Next, simply scatter the crushed shells around your lavender, rosemary, or thyme plants.
For those cultivating lavender, thyme, or rosemary indoors, eggshells can be cleverly transformed into attractive miniature plant containers. Carefully slice away the top of an egg using a sharp knife, making sure the base stays intact, then rinse them thoroughly to eliminate any leftover yolk, which could draw pests or mould.
While still moist, make a small hole at the bottom of each shell using a needle. Proper drainage is vital to stop water from gathering and to keep your potted herbs in good condition. Use a tablespoon to fill each eggshell with soil, ensuring you leave a one-centimetre gap at the top. Herb-specific compost is widely available at most garden centres, although woody herbs will need a light, sandy and slightly alkaline variety.
Next, simply sprinkle a few seeds into each eggshell and label them with the herb's name using a permanent marker. Water daily, place them in a sunny spot, and before you know it, you will have a flourishing herb garden in full swing.
