German chamomile is one of those plants that rewards a light hand, so resist the urge to pamper it. Sow seed right on the surface in early spring — the seeds need light to germinate, so don't bury them; just press them into a finely raked bed and keep it lightly moist until they sprout. It actually prefers leaner, well-drained soil, so skip the heavy compost and rich feeding that you'd give a vegetable bed. The most common mistakes I see are overwatering and sowing too deep, both of which lead to leggy, sad seedlings. Give it full sun, thin the plants to about 8-10 inches so air moves through, and you'll have a froth of blooms by early summer. It self-seeds generously, so let a few flowers go to seed and you'll likely never have to sow it again.
The flowers are the prize here — harvest them on a dry morning once the white petals start to reflex downward, when the essential oils are at their peak. Dried and steeped, they make the classic calming tea that's been used for centuries to ease an upset stomach, settle the nerves before bed, and soothe restlessness. Traditionally a cooled, strong infusion was used as a gentle skin wash for irritation and minor inflammation, and as a hair rinse to brighten fair hair. In the kitchen the apple-scented blooms lend themselves to infused syrups, custards, and shortbreads — use them sparingly, since too many turn the flavor bitter. Dry the harvest thoroughly on screens out of direct sun and store in a sealed jar to keep that sweet, hay-like aroma through winter.
Powdery mildew
White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.
Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.
Damping Off
Seedlings collapse at the soil line with thin, water-soaked stems; seeds may fail to emerge or rot before sprouting.
Sow in well-draining mix, avoid overwatering, and ensure good airflow. Remove affected seedlings and let the surface dry between waterings.
Botrytis (grey mould)
Grey fuzzy mould on petals and stems, worst in cool wet conditions.
Remove affected parts immediately. Improve air circulation. Avoid overhead watering. Apply copper fungicide if severe.
Aphids
Aphididae →Clusters of small soft insects on new growth and flower buds.
Knock off with a strong jet of water. Ladybirds and lacewings are natural predators. Insecticidal soap as last resort.