Arizona gardeners benefit from planting calendula seeds in October when temperatures begin to drop. Finding the Best Time To Plant Calendula In Arizona is crucial for getting those bright orange and yellow blooms through our unique desert seasons. Calendula, also known as pot marigold, actually thrives in our cooler months, unlike many other flowers that struggle with the intense summer heat.
If you plant at the right time, you can enjoy flowers from late fall all the way through spring. The key is to avoid our scorching summer temperatures. Let’s break down exactly when and how to plant calendula in Arizona for the best results.
Best Time To Plant Calendula In Arizona
The ideal window for planting calendula in Arizona is from early October through November. This timing allows the seeds to germinate in warm soil, then grow strong roots as temperatures cool down. You can also plant again in late February or early March for a spring bloom, but fall planting gives you a much longer flowering season.
Calendula is a cool-season annual that actually stops blooming when temperatures consistently go above 90°F. In Arizona, that means your main growing season runs from October through April. The exact timing depends slightly on where you live in Arizona.
Planting Calendula In Different Arizona Zones
Arizona has several climate zones, from the low desert around Phoenix to the high country near Flagstaff. Your planting time will vary based on your elevation and local temperatures.
- Low Desert (Phoenix, Tucson, Yuma): Plant seeds from mid-October through November. You can also do a second planting in late February.
- Mid-Elevation (Prescott, Sedona, Payson): Plant seeds in September or early October. These areas get frost earlier, so start a bit sooner.
- High Country (Flagstaff, Show Low): Plant seeds in late August or early September. You’ll get blooms before the first hard frost, then again in spring.
No matter where you live, avoid planting calendula during the hot summer months. Seeds won’t germinate well when soil temperatures are above 85°F, and plants will quickly bolt and die.
Why Fall Planting Works Best For Arizona
Calendula is native to the Mediterranean region, which has a climate similar to Arizona’s cooler months. The plant naturally grows during mild, wet winters and dies back during hot, dry summers. By planting in fall, you’re working with the plant’s natural cycle.
Here are the main benefits of fall planting:
- Longer bloom period: Fall-planted calendula can bloom from November through April, giving you six months of flowers.
- Less water needed: Cooler temperatures mean less evaporation, so you water less often.
- Fewer pests: Many common garden pests are less active during cooler months.
- Better germination: Soil temperatures in the 60-70°F range are perfect for calendula seeds.
Spring planting works too, but you’ll get a much shorter bloom period. Plants started in March may only flower for 6-8 weeks before the heat shuts them down.
How To Plant Calendula Seeds In Arizona
Planting calendula is straightforward, even for beginners. Follow these steps for the best results in our desert soil.
Step 1: Prepare The Soil
Calendula isn’t picky about soil, but it does need good drainage. Arizona’s native soil is often heavy clay or caliche, which can hold too much water. Amend your soil with compost or aged manure to improve drainage and add nutrients.
If you’re planting in containers, use a good quality potting mix. Calendula does well in pots as long as they have drainage holes.
Step 2: Sow The Seeds
Calendula seeds are large and easy to handle. They look like small, curved crescents. Plant them about 1/4 inch deep in the soil.
- Make a small hole with your finger or a dibber.
- Drop in 2-3 seeds per hole.
- Cover lightly with soil.
- Space holes about 8-12 inches apart.
You can also scatter seeds on the soil surface and rake them in lightly. Calendula self-seeds readily, so you might get volunteers next season.
Step 3: Water Properly
After planting, water the seeds gently but thoroughly. Keep the soil consistently moist until seeds germinate, which usually takes 5-14 days. Once seedlings appear, water deeply but less frequently.
In Arizona’s dry climate, you might need to water every 2-3 days during germination. After that, watering once or twice a week is usually enough, depending on temperatures.
Step 4: Thin Seedlings
When seedlings have their first set of true leaves, thin them to one plant per hole. Choose the strongest seedling and snip the others at soil level. Don’t pull them out, as this can disturb the roots of the remaining plant.
Thinning gives your calendula room to grow and prevents overcrowding, which can lead to disease.
Caring For Calendula In Arizona
Once your calendula is established, it requires minimal care. Here’s what you need to know to keep them blooming all season.
Watering
Calendula prefers consistent moisture but doesn’t like wet feet. Water deeply when the top inch of soil feels dry. In Arizona’s dry air, you might need to water more often during windy periods.
Drip irrigation works well for calendula. It delivers water directly to the roots without wetting the foliage, which helps prevent fungal diseases.
Fertilizing
Calendula isn’t a heavy feeder. A light application of balanced fertilizer at planting time is usually enough. If your soil is poor, you can fertilize once a month with a half-strength liquid fertilizer.
Avoid high-nitrogen fertilizers, which promote leaf growth at the expense of flowers. Look for a fertilizer with a higher middle number (phosphorus) to encourage blooming.
Deadheading
Remove spent flowers regularly to encourage continuous blooming. Simply pinch or snip off the faded flower heads. This tells the plant to produce more flowers instead of setting seed.
If you want calendula to self-seed, leave some flowers on the plant at the end of the season. The seeds will drop and germinate on their own next fall.
Pest And Disease Management
Calendula is relatively pest-free in Arizona’s cooler months. You might occasionally see aphids or whiteflies. A strong spray of water from the hose usually takes care of them.
Powdery mildew can be a problem if plants are overcrowded or if humidity is high. Space plants properly and water at the base to minimize this issue.
Companion Planting With Calendula
Calendula is an excellent companion plant for vegetables and herbs. It attracts beneficial insects like ladybugs and lacewings, which eat aphids and other pests. The flowers are also edible and make a colorful addition to salads.
Good companions for calendula include:
- Tomatoes (plant in spring before it gets too hot)
- Peppers
- Eggplant
- Beans
- Lettuce
- Herbs like basil and parsley
Avoid planting calendula near potatoes or brassicas like cabbage and broccoli. Some gardeners report that calendula can inhibit the growth of these plants.
Harvesting And Using Calendula
Calendula flowers are not just pretty, they’re useful too. The petals have anti-inflammatory properties and are commonly used in salves, teas, and skincare products.
Harvesting Flowers
Pick flowers when they are fully open, usually in the morning after the dew has dried. Choose flowers that are bright and fresh, not faded or damaged.
For the best quality, harvest every few days during peak bloom. This also encourages more flowers to form.
Drying Calendula
To dry calendula, spread the flower heads on a screen or drying rack in a warm, dark, well-ventilated area. Avoid direct sunlight, which can fade the color and reduce potency.
Once the petals are completely dry and crisp, store them in an airtight container away from light. Dried calendula petals can last up to a year.
Using Calendula
Here are some common uses for calendula:
- Calendula tea: Steep dried petals in hot water for 10 minutes. The tea has a mild, slightly bitter flavor.
- Calendula oil: Infuse dried petals in a carrier oil like olive or jojoba oil for use in salves and lotions.
- Calendula salve: Combine calendula oil with beeswax to make a soothing balm for dry skin or minor cuts.
- Edible flowers: Add fresh petals to salads, soups, or rice dishes for a pop of color.
Common Problems And Solutions
Even with the best care, you might encounter some issues. Here are common problems Arizona gardeners face with calendula and how to solve them.
Leggy Growth
If your calendula plants are tall and spindly with few flowers, they’re probably not getting enough light. Calendula needs full sun, which in Arizona means at least 6 hours of direct sunlight daily.
Solution: Move plants to a sunnier location or trim back nearby plants that might be shading them.
Yellow Leaves
Yellowing leaves can indicate overwatering, underwatering, or nutrient deficiency. Check the soil moisture first. If it’s soggy, let it dry out before watering again.
Solution: Adjust your watering schedule. If the soil is dry and leaves are still yellow, try a light application of balanced fertilizer.
No Flowers
If your calendula is all leaves and no flowers, the most likely cause is too much nitrogen or not enough sun. High temperatures can also cause calendula to stop blooming.
Solution: Switch to a fertilizer with higher phosphorus and potassium. Make sure plants are getting enough sun. If temperatures are above 90°F, wait for cooler weather.
Bolting
Bolting is when a plant suddenly sends up a flower stalk and goes to seed. This happens when temperatures get too hot or when the plant is stressed.
Solution: Plant at the right time to avoid heat stress. Keep plants well-watered and mulched to keep roots cool.
Frequently Asked Questions
Can I plant calendula in the summer in Arizona?
No, summer temperatures in Arizona are too hot for calendula. Seeds won’t germinate well, and plants will quickly bolt and die. Stick to fall and early spring planting.
How long does calendula bloom in Arizona?
With fall planting, calendula can bloom from November through April, giving you about 6 months of flowers. Spring-planted calendula blooms for a shorter period, usually 6-8 weeks.
Does calendula need full sun in Arizona?
Calendula does best in full sun, but in Arizona’s intense summer heat, some afternoon shade can help. For fall and winter planting, full sun is ideal.
Can I grow calendula in pots in Arizona?
Yes, calendula grows well in containers. Use a pot with drainage holes and quality potting mix. Water more often than in-ground plants, as pots dry out faster.
Is calendula drought tolerant?
Calendula is somewhat drought tolerant once established, but it blooms best with regular water. In Arizona’s dry climate, don’t let the soil dry out completely for extended periods.
Final Tips For Success
Planting calendula at the right time is the most important factor for success in Arizona. Remember these key points:
- Plant seeds in October or November for the longest bloom period.
- Choose a sunny spot with well-draining soil.
- Water consistently, especially during germination.
- Deadhead regularly to keep flowers coming.
- Enjoy the blooms from fall through spring.
Calendula is one of the easiest flowers to grow in Arizona’s cooler months. With minimal effort, you’ll have a continuous supply of bright, cheerful flowers that brighten up your garden and your kitchen. Start with a small patch this fall, and you’ll likely find yourself planting more next year.
The key is timing. Plant too early and the heat will kill your seedlings. Plant too late and you’ll miss the best growing weather. Stick with the October through November window, and your calendula will thrive in Arizona’s unique climate.
Once you see those first orange blooms in late fall, you’ll understand why calendula is a favorite among desert gardeners. It’s a rewarding plant that gives back so much for so little effort. Give it a try this season and see the difference proper timing makes.