Feverfew

Sow feverfew on the surface, about two weeks before last frost

Sow roughly two weeks before your predicted last frost date. Press the seed onto the soil surface and tamp it in lightly rather than covering it. Hold seedlings near 65 to 70 F by day and 50 F at night; germination takes 10 to 15 days. Space transplants 9 to 12 inches apart. Feverfew seed requires light to germinate, so soil raked over the top simply holds it dormant instead of covering it in.

Shear off spent blooms before the seed ripens

Deadhead or shear the spent blooms off as soon as they fade rather than leaving them to brown on the plant. If the planting has already spread, pull the volunteer seedlings while they are small. Feverfew self-seeds aggressively, and every seed head left to ripen becomes next season's colony in the surrounding bed.

⚠ Handling the foliage can cause contact dermatitis, so wear gloves when shearing.

Check leaf undersides for spider mites

Turn a few leaves over through the summer and look for fine stippling and webbing. Feverfew has no serious disease or insect problems, so mites are the one pest worth tracking on this plant. Spider mites are the only pest that reliably troubles feverfew, and they build up on the undersides of leaves where the damage is easy to miss until the foliage is bronzed.

Cut the top two-thirds before or during bloom

Harvest any time from before bloom through full bloom by taking the top two thirds of the plant. Leave about four inches of stem for regrowth so you can take a second cut later in the season (per Manitoba Agriculture), and harvest early enough to allow sufficient time for that regrowth. Cutting twice in a season yields more total dry material than a single harvest. Dry the cut material in shade out of direct sunlight, then rub it through quarter-inch hardware cloth to separate the leaves and flowers from the stems. Leaf and flower are the marketable and medicinal fraction, standardized on parthenolide, and the stems are screened out afterward, so the harvest is timed and cut to take the leafy top rather than the whole plant.

⚠ Feverfew causes contact dermatitis and airborne dermatitis has occasionally been reported (NC State Extension Plant Toolbox). Wear gloves and long sleeves when cutting, and avoid breathing the dust when rubbing dried material through a screen.