Feverfew in Zone 6A — Pacific Northwest

Feverfew is a fantastic addition to any Pacific Northwest garden. Its charming daisy-like flowers brighten up borders, attract beneficial insects, and the cool nights here seem to intensify its slightly bitter, medicinal aroma. Plus, it's relatively low-maintenance, making it a great choice for our busy lives.

While we might not have the scorching summers some regions do, our cool soil in spring and occasional late blight scares present unique challenges. But with careful timing and attention, Feverfew thrives in our 148-day growing season, rewarding you with blooms from mid-summer well into fall.

Starting Feverfew indoors is an option, especially if you want a head start. Begin in early to late March, about eight weeks before you plan to transplant outdoors. Use seed trays or small pots filled with a good seed-starting mix and gently press the tiny seeds into the surface – they need light to germinate.

Keep the trays consistently moist, using bottom watering to avoid disturbing the seeds, and maintain a temperature of around 70°F. A heat mat can be helpful since our springs tend to be slow to warm up. Once seedlings emerge, ensure they get plenty of light, either from a sunny window or a grow light.

Transplant your Feverfew seedlings outdoors in early to late May, once the danger of frost has passed. Before planting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the cooler temperatures and stronger sunlight.

Choose a spot with full sun to part shade and space the plants 12-15 inches apart. Our overcast spring days can sometimes linger, so waiting for a stretch of sunshine will help your transplants settle in quickly.

Direct sowing Feverfew is a straightforward method, especially if you’re not in a rush to get blooms. Sow seeds outdoors from early May through mid-July. The soil needs to be workable and ideally around 60-70°F for good germination.

Prepare the soil by loosening it and removing any weeds. Scatter the seeds thinly over the surface and gently press them into the soil. Keep the soil consistently moist until seedlings emerge. Thin seedlings to 12-15 inches apart once they are a few inches tall.

Feverfew is wonderfully drought-tolerant once established, making it a great fit for our dry summer months in the Pacific Northwest. During the wet springs, you might not need to water at all, relying on natural rainfall to keep the soil moist. However, during our drier summer stretches, keep an eye on the soil moisture.

Use the "finger test" – stick your finger about two inches into the soil. If it feels dry, it's time to water. Aim for about an inch of water per week during dry spells, watering at the base of the plant to avoid wetting the foliage and minimizing potential fungal issues.

Since our humidity is typically low during the summer, overhead watering isn't as problematic as it might be in more humid climates, but watering at the base is always preferable. Watch for signs of underwatering, like wilting leaves, or overwatering, such as yellowing foliage. A light layer of mulch around the base of the plants can help retain moisture and keep the soil cool.

Deadheading is key to keeping your Feverfew blooming continuously throughout the season. As soon as the daisy-like flowers start to fade, snip them off just below the flower head. This encourages the plant to produce more blooms rather than putting energy into seed production.

You can deadhead throughout the summer and into early fall. After the main flowering period, or as the first frost approaches in early October, cut the plants back to about half their size. This tidies them up and prepares them for winter. Be aware that Feverfew self-seeds aggressively if you let the flowers go to seed.

You can expect your first Feverfew harvest starting in mid-July and continuing through mid-October, about 70 days after sowing or transplanting. The best time to harvest is when the small, daisy-like flowers are in full bloom. Look for vibrant, healthy foliage and flowers that haven't started to fade.

To harvest, simply snip off the stems just above a leaf node, using clean scissors or pruners. Harvest regularly to encourage continued production. As the first frost approaches in early October, you can harvest the remaining foliage and flowers for drying and later use.

Here are a few common problems you might encounter with Feverfew in the Pacific Northwest:

Self-seeds prolifically:

• What it looks like: Numerous small Feverfew seedlings popping up everywhere in your garden, even in unwanted areas.
• What causes it: Letting the flowers go to seed allows the plant to spread its seeds widely. Our mild, wet winters often provide ideal conditions for germination.
• How to fix/prevent it: Deadhead regularly to prevent seed formation. If you miss some, be diligent about pulling out unwanted seedlings as soon as you spot them.

Aphids:

• What it looks like: Clusters of tiny soft-bodied insects (green, black, or white) on stems and leaf undersides. Sticky honeydew residue. Curled or distorted new growth.
• What causes it: Rapid-reproducing sap-sucking insects. Populations explode in warm weather. Ant colonies may farm them for honeydew.
• How to fix/prevent it: Strong water spray knocks them off. Encourage ladybugs and lacewings (natural predators). Insecticidal soap for heavy infestations. Neem oil works systemically. Avoid excess nitrogen fertilizer (it attracts them).

Leaf Miners:

• What it looks like: White or yellow winding trails or blotches on the leaves.
• What causes it: Larvae of small flies burrowing between the upper and lower leaf surfaces, feeding on the leaf tissue.
• How to fix/prevent it: Remove and destroy affected leaves. Use row covers to prevent the adult flies from laying eggs on the plants. Insecticidal soap or neem oil can also be effective.

Pacific Northwest Specific Challenges: Although Feverfew is fairly adaptable, our mild heat and dry-summer rainfall can create conditions for aphid infestations. Regularly inspect your plants and take action quickly to prevent problems from escalating.

Feverfew makes a good companion plant for several garden vegetables and ornamentals. Planting it near tomatoes can help deter pests, as its strong scent repels some insects that bother tomatoes. Roses also benefit from Feverfew's presence, as it can help to repel aphids and other rose pests.

Additionally, many herbs, such as rosemary and thyme, thrive alongside Feverfew. Avoid planting Feverfew near plants that are highly susceptible to leaf miners, as it may attract these pests and spread them to other plants in your garden.