Feverfew in Zone 6A — Mountain West

Feverfew is a fantastic addition to any Mountain West garden. Its cheerful, daisy-like flowers bring a touch of cottage charm, and its reputation as a traditional herbal remedy adds a layer of practicality. Plus, the cool nights we often have here seem to intensify its aromatic oils, making it even more delightful.

Our high altitude, intense sun, and short growing season certainly present challenges. But with a little planning, you can successfully grow Feverfew in our Zone 6A gardens. With a growing season around 153 days, you'll find that Feverfew's relatively quick maturity means you can enjoy its benefits even with our shorter summers.

Starting Feverfew indoors is an option, especially if you want a head start on the season, but direct sowing works just fine, too. If you choose to start indoors, aim for mid-February through mid-March, about eight weeks before you plan to transplant.

Use seed trays filled with a good seed-starting mix. Keep them consistently moist by bottom watering to avoid disturbing the tiny seeds, and provide warmth (around 70°F) and plenty of light – a grow light is highly recommended, especially given our late springs and often cloudy days early in the season.

Remember that our spring weather in the Mountain West can be unpredictable. Starting indoors gives you more control, but requires careful monitoring to prevent leggy seedlings due to insufficient light.

Transplanting Feverfew outdoors should happen late April through late May, once the danger of hard frost has passed. Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Choose a spot with full sun to partial shade, and space the plants 12-15 inches apart. Keep an eye on the weather forecast. We can still get surprise frosts during this time, so be ready to cover your young plants if necessary.

Direct sowing Feverfew is a simple and effective way to get these plants going in the Mountain West. Wait until early May through early July, when the soil has warmed up a bit.

Prepare a well-drained seedbed and sow the seeds shallowly. Gently press them into the soil. Keep the soil consistently moist until germination. Thin seedlings to 12-15 inches apart. Direct sowing is less work upfront, but the plants will take a bit longer to mature.

Feverfew is relatively drought-tolerant once established, making it a good choice for our dry Mountain West climate. However, consistent watering is important, especially during the first few weeks after planting, whether you've transplanted or direct-sown.

During the heat of summer (which, at our altitude, is more "moderate" than scorching), check the soil moisture regularly. Stick your finger about two inches deep into the soil. If it feels dry, it's time to water. Aim for about 1 inch of water per week, delivered in one or two deep soakings rather than frequent light sprinklings.

Water at the base of the plants to avoid wetting the foliage, which can reduce the risk of fungal diseases in our low-humidity environment. Signs of underwatering include wilting and yellowing leaves. Overwatering can lead to root rot, so ensure your soil drains well. A layer of mulch, like shredded bark, will help retain moisture and regulate soil temperature.

Deadheading is key to keeping your Feverfew blooming throughout the season. Simply snip off the spent flowers just below the flower head. This encourages the plant to produce more blooms rather than putting energy into seed production.

Throughout the growing season, remove any yellowing or dead leaves to keep the plant healthy and attractive. After the main flowering period (around early October, before our first expected frost), you can cut the plant back to a few inches above the ground. This helps tidy things up and encourages new growth in the spring. Be aware that Feverfew self-seeds readily, so if you don't want it spreading, be diligent about deadheading before the seeds mature.

You can expect your first Feverfew harvest in early July through early October, about 70 days after planting. Look for the small, daisy-like flowers to be fully open and vibrant. The flowers are the part typically used for herbal remedies.

To harvest, simply snip off the flower heads with a pair of scissors or pruners. Harvest in the morning after the dew has dried for the best flavor and potency. Feverfew will continue to produce flowers throughout the summer if you keep deadheading, so you can harvest multiple times.

As the first frost approaches in early October, you can harvest any remaining flowers to dry for later use. Even if the plant gets nipped by frost, the roots are hardy, and it will likely return next spring.

Here are the most common problems you might encounter with Feverfew in the Mountain West:

Self-Seeds Prolifically

• What it looks like: Seedlings popping up everywhere in your garden where you didn't plant them.
• What causes it: Feverfew is an enthusiastic self-seeder. Letting the flowers go to seed guarantees a swarm of new plants next year.
• How to fix/prevent it: Deadhead regularly! Remove spent flowers before they form seeds. If you want to save seeds, collect only a few flower heads and dispose of the rest properly.

Aphids

• What it looks like: Clusters of tiny (green, black, or white) soft-bodied insects 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. Our warm days and cool nights in the Mountain West can create ideal conditions for aphid outbreaks.
• 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: Pale, winding trails or blotches on leaves. You might see tiny larvae inside the tunnels if you hold the leaf up to the light.
• What causes it: Leaf miner larvae tunnel through the leaf tissue, feeding as they go.
• How to fix/prevent it: Remove and destroy affected leaves. Cover plants with row covers to prevent adult flies from laying eggs. Beneficial nematodes can help control soil-dwelling stages.

Mountain West Specific Challenges: Feverfew generally handles our moderate-at-altitude summer heat and low humidity well. The dry climate helps reduce the risk of fungal diseases that plague other regions. However, be vigilant about watering during dry spells, and protect young plants from intense UV radiation with shade cloth if needed. Hail can also damage foliage, so consider providing some protection during severe storms.

Feverfew makes a good companion plant for several garden favorites in our Mountain West gardens. Plant it near tomatoes to help repel certain pests. Roses also benefit from Feverfew's presence, as it can deter aphids and other rose pests.

Herbs like rosemary and thyme are good companions, too. Their strong scents can help confuse pests, and they share similar growing requirements (full sun and well-drained soil). Avoid planting Feverfew near anything in the brassica family (cabbage, broccoli, kale), as it can attract cabbage white butterflies.