The weeks around the summer solstice are the peak harvest window for a remarkable range of medicinal herbs, and the herbalist who is paying attention is busy. The light is long, the volatile oil content of aromatic herbs is at its highest in summer warmth, and the flowering tops of the most important aerial-part herbs are at their most medicinally concentrated before they go to seed. What you harvest and how you harvest it in these weeks is directly reflected in the quality of your apothecary through the coming year.
What to Harvest in June
St. John’s Wort flowering tops: harvest when the first flowers are opening, in the morning of a dry sunny day. The red oil-glands in the petals and leaves are at peak concentration at this moment. Make the oil immediately from fresh plant material.
Elderflower: if not already harvested in May, the last of the elder flowers are available in early June. Harvest the fully open, strongly fragrant corymbs on a dry morning. Use the same day for fresh preparations or dry quickly at low temperature.
Lavender: harvest the flowering spikes when about half the flowers on each spike are open. Bundle and dry hanging in a cool, dark, well-ventilated place.
Lemon balm: harvest the leafy tops before the plant comes into full flower, when the volatile oil content is highest. Fresh plant is always preferable for this herb; freeze-dry or tincture immediately if possible.
Calendula: harvest flowers daily or every other day once they are fully open. This constant harvesting keeps the plant flowering prolifically through summer.
Drying Well
The quality of your dried herb depends almost entirely on how quickly and at what temperature you dry it. High-volatile-oil herbs (lavender, lemon balm, chamomile) need to be dried quickly at temperatures not exceeding about 35 to 40 degrees Celsius, in good airflow and away from direct light. A dehydrator set at its lowest temperature is often the best tool for reliable consistent results. A well-ventilated dark shed with plants spread on screens works well for larger quantities.
Store dried herbs in airtight, opaque containers (amber glass or dark tins are ideal). Label with the plant name, part used, and harvest date. Check the smell: dried herbs should smell alive and characteristic of the fresh plant, not flat or musty. If the smell has gone, so has most of the medicine.
The Herbalist Codex app has detailed harvest and drying guidance for each herb in season right now. This is the moment the apothecary is built. Use it well.