The botanical name of Calendula is Calendula officinalis and is actually a short-lived perennial in warmer climates. However in cooler climate zones the plant is usually grown as an annual flower in garden beds and containers. Calendula is also commonly known as pot marigold, although is actually different from the common marigold (Tagetes spp.). Calendula plant is part of the Asteraceae family along with chrysanthemums and daisies, and it really has a daisy-like appearance. Calendula flowers are planted in spring after the last frost and they grow relatively quickly, flowering 6 to 8 weeks from seeding.
Calendula Plant Info
The botanical name: The botanical name is Calendula officinalis.
The common name: The common names are Calendula, common marigold, pot marigold.
Family: Belong to Asteraceae family.
The plant type: Calendula is perennial, annual.
The mature size: The mature size is about 1-2 feet tall, 1-2 feet wide.
The sun exposure: The plant prefers full, partial sun.
The soil type: The plant does well in well-drained soil.
The soil pH: Neutral
The blooming time: The blooming time is spring, summer, fall.
The flower color: The flower colors are orange, yellow, white, red, pink.
Plant hardiness zones: USDA 2a-11b
The native area: Calendula is native to Mediterranean.
Calendula Plant Care
This plant is primarily an annual plant unless you live in hardiness zones nine to eleven, where the plant can be easily grown as a perennial.
Calendula plant is actually easy to grow from seeds directly sown in the garden or containers. The seeds can be planted indoors in early spring and then repot or transplant the sturdy seedlings after the danger of frost has passed. The plant can tolerate poor conditions but they grow best when it has rich soil. Once it’s established, the plant does not need much water or fertilizer to grow. Calendula plant is actually a full sun plant, nevertheless the plant it’s not a fan of sweltering hot temperatures and it might start wilting in intense heat.
Pinch back the young plants in other to promote more compact, bushy growth and it will also prevent the plants from becoming leggy. You can deadhead the old flowers to encourage re-blooming.
Light requirement: Calendula plants generally prefer full sun, although it sometimes languishes during the hottest months unless the plant receives some afternoon shade.
Soil requirement: Calendula plant is like most members of the daisy family, they actually need a well-drained soil that is high in organic material. A dense, wet soil can easily cause the roots to rot. Calendula plant tolerates a wide range of soil pH although prefers a slightly acidic to neutral soil (6.0 to 7.0).
Water requirement: Water the plants frequently until the plants are established. The mature Calendula plants thrive on only occasional watering. You need to avoid too much water with these plants.
Temperature and humidity requirement: The plant actually prefers mild summer temperatures and they may die away by the end of summer in very hot climates. A hard freeze can kill the Calendula plants. If you’re expecting some frost for a day or so, you can protect the Calendula plants with a frost blanket overnight and then uncover them as the sun warms up the air the next day. 3 to 4 inches of mulch will also protect the Calendula plants from cold temperatures.
Fertilizer requirement: The Calendula plants do not need much in the way of feeding. If they are planted in fertile garden soil, the plant requires no additional feeding at all. Marginal soils may require you feeding them with a balanced, water-soluble fertilizer. On the other hand over-feeding them can make the plants leggy and spindly.
Container grown Calendula plants may require monthly feeding with a diluted, balanced fertilizer.
Varieties of Calendula
There are several cultivars of Calendula officinalis. Some of the popular varieties are:
- Pink Surprise Calendula: This particular variety has ruffled gold and yellow flowers and sometimes with pink edges and dark apricot centers.
- Calendula Touch of Red: Calendula Touch of Red has flowers with a mixture of orange and red shades with red-tipped petals.
- Calendula Greenheart Orange: Calendula greenheart orange has flowers with orange petals surrounding the lime-green centers, the plant is a very unusual looking plant.
- Calendula Citrus Cocktail: The Calendula Citrus Cocktail is a compact, short plant with yellow and orange flowers, they actually works well in containers.
- Calendula Dwarf Gem: This particular variety is a compact variety with double-petal blooms of orange, yellow, and apricot, they also work well in containers.
- Calendula Indian Prince: Calendula Indian Prince is a tall variety and they are heat-tolerant with orange and yellow blooms.
- Calendula Golden Princess: This particular variety comes with bright yellow blooms with a contrasting black center.
How to Harvest Calendula
Most people actually find the peppery taste somewhat bitter, calendula flowers and leaves can be used as edible flowers in salads and other recipes, either dried or fresh. Also the petals can be used to create a very rich yellow dye.
You can easily collect the calendula flowers in the late morning after the dew has dried. You should pick the flowers when they are fully open. To dry the calendula flowers, spread out the cut flower heads on a screen in a very dry, shady spot. You have to turn them occasionally until they are papery dry and then store them in canning jars until you are ready to use them.
Pest and disease control
This plant actually has no serious insect or disease problems. The Calendula plant can sometimes be susceptible to powdery mildew, which you can easily remedy by providing good air circulation.
Most times slugs and snails feed on the Calendula plants, most especially when the plants are young. Make sure you keep the ground clear of debris to minimize slug and snail damage. Whiteflies and aphids can sometimes be a problem. To control whiteflies and aphids you can easily spray them with water or treat them with insecticidal soap.