One of the most popular fall flowers, the Chrysanthemum is a reliable ornamental plant. The range of varieties on offer means that you will find flowers suitable for filling large spaces as well as smaller varieties that are ideal for pots or window boxes. They are also pleasingly easy to grow.
Chrysanthemum plants are hardy in planting Zones 5 to 9. Some cultivars are also hardy in Zone 4. While dwarf and compact varieties are available, most cultivars enjoy a spread of 1 to 3 ft and achieve a similar height. They can flower in shades of purple, red, orange, yellow and white. Some varieties also produce bicolor blooms.
Here is everything you need to know about growing chrysanthemum flowers.
Showy chrysanth flowers are a staple of the late summer and fall garden.
Warning Chrysanthemum plants contain substances that can be toxic to dogs, cats and horses if consumed.
Different Chrysanthemum Varieties
You can purchase either chrysanthemum plants or rooted cuttings. Both are sold ready for transplanting into pots or flower beds. While garden stores often have a number of chrysanthemum plants for sale, specialist nurseries may have a wider selection available.
Take the time to explore the different varieties and find something that suits your garden.
Purchase the healthiest plant that you can find. Try to buy plants that have more buds than open flowers.
The vast range of varieties on offer means that you are sure to find something that appeals to your taste.
Chrysanthemum flowers come in a range of shapes, sizes, colors and flowering times. They are often divided into 8 distinct types.
Single Chrysanthemums are one of the most common varieties. Including varieties such as Tenderness and Daisy the flowers have a flat center and up to 5 rows of long, daisy like petals. The foliage is usually lobed but can also be toothed and often releases a distinct aroma when crushed.
Pom pom is the smallest variety, producing several pom pom like flowers on each stem. The smallest cultivar is known Button Chrysanthemums and includes cultivars such as Baby Tears and Small Wonder. Larger pom pom flowers include the attractive Moonbeam cultivar.
Anemone flowers have a raised center that is surrounded by dark, short petals. These offer contrast with the flowers radiating daisy-like petals. Cultivars include Mansetta Sunset. Anemone ‘mums are not often seen at garden stores. Instead these plants are usually found at specialist nurseries.
Spider ‘mums are named for the flowers’ long, curling spider-like petals. This is one of the more unusual cultivars. Varieties include Cremon and Anastasia.
Spider cultivars have distinctive, curling petals.
Spoon ‘mums produce attractive flowers with long, spoon-like petals. Happy Face and Starlet are among the more commonly grown varieties.
Decorative ‘mums are short plants that produce large, showy flowers with curved petals. Cultivars include Indian Summer and Tobago.
Quill flowers are known for their straight, tube-shaped petals. A delicate cultivar that struggles to survive cold temperatures it is best grown as an annual. Cultivars include Muted Sunshine and Matchsticks.
Cushion is a hardy variety. A bushy, low growing cultivar, it produces scores of mid-sized flowers. Chiffon, Ruby Mound and Valour are all popular cushion varieties.
You may also encounter plants described as Garden and Florist chrysanthemums. Garden chrysanthemums, also known as Belgian ‘mums, are hardy and suited to planting outside where they are usually grown as annuals. Florist varieties are better suited to planting indoors in pots.
Where to Plant
In the ideal position, if cared for correctly, chrysanthemum plants flower from late summer until the first frost.
Chrysanthemum plants prefer full sun positions during the growing season. They also grow well in partial shade positions. However, the plants may not be as strong or flowering may not be as profuse when compared to plants in sunnier spots.
Sun loving flowers, flowering begins as daylight hours decrease.
Chrysanthemum plants are ideal for both flower beds and raised beds. They are also suitable for container gardens. If you are growing in containers, try moving the plants to a shadier spot after the buds have developed. This can prolong the flowering season.
Plant in rich, well draining soil. Working in organic matter before planting helps to enrich the soil. It also helps to improve drainage.
Chrysanthemum plants are short-day plants. This means that their flowering is triggered by the shortening of daylight that occurs in late summer and early fall. To force the flowers to emerge earlier in the year you can grow in a light controlled greenhouse.
When to Plant
Plant perennials in early spring or at least 6 weeks before the first harsh frost. This gives the plants time to establish themselves before the winter temperatures hit.
If you are growing chrysanthemum plants as annuals, plant them when they are in flower. This is usually at some point from late summer until early fall.
In northern areas plant hardy cultivars in the spring. In the south plant in spring or fall. Many growers prefer to plant in the fall. This helps the plants to avoid the summer heat.
Chrysanthemums can be planted in flower beds or containers. They can also successfully be grown indoors.
Growing Chrysanthemum Plants Indoors
Position your chrysanthemum in a light position, a healthy flowering plant requires at least 4 hours of light every day. A south facing windowsill is an ideal position. The position should not be filled with too much artificial light, especially at night. This can stress the plant and deter flowering.
Avoid overly humid positions. Ideally your plant should be somewhere where air is able to freely circulate.
How to Plant
Chrysanthemum plants happily grow in beds and containers.
To plant in a flower bed, dig the soil over before planting. Working in organic matter such as well-rotted manure or compost helps to enrich the soil. It also improves drainage.
Dig a hole in the soil large enough to hold the plant or rooted cutting.
Position the plant in the center of the hole. The top of the root system should sit just below the level of the soil. When you are happy with the position of the plant, gently backfill the hole. Be careful not to sink the plant down too deeply as you fill in the hole.
Firm down the soil and water well.
Continue to water well, making sure that the soil doesn’t dry out, for about a fortnight. This gives the plants time to become established in their new home.
These can be bushy or dense plants. Correctly spacing them out helps the air to circulate between the plants. This, in turn, helps to keep plants healthy and disease free.
If you are planting more than one chrysanth, space the plants about 8 inches apart. This helps air to circulate between the plants, keeping them healthy and disease free. Spacing requirements can vary between varieties. For the exact spacing, check the information on the plant label before planting.
Planting in Containers
After purchase, repot your plant as soon as possible in a slightly larger container.
You also need to repot perennial plants if they become root bound. The most obvious sign that your plant has outgrown its home is roots sticking out of the drainage holes in the bottom of the pot. The soil may also dry out more quickly and flowering will be less profuse.
Repot root bound plants in a similar sized, or slightly larger, pot. The best time to repot is in the spring.
The new pot should be clean, have drainage holes in the bottom and be filled with fresh potting soil.
Carefully remove the plant from the pot and gently separate the roots if they are in a tight ball. If the plant is difficult to remove, squeeze the sides of the pot. This helps to loosen the soil.
Make a hole in the fresh soil large enough to comfortably hold the root system. Position the plant in the hole, the top of the root system should sit level with the soil. When you are happy with the position of the plant, firm the soil down and water well.
Place the pot in a light position. Continue to water well for two weeks after repotting plants. This helps the plant to establish itself in its new home.
Caring for Chrysanthemum Flowers
Once planted chrysanthemum care is pleasingly straightforward.
Keep the area around your plants clear and weed free. Weeds can harvest moisture and nutrients from the soil, depriving your flowers. They can also smother slower growing plants.
Taller varieties may require some support. A simple stake, such as a bamboo cane, is best installed when planting. Garsum Bamboo Sticks provide sturdy support for growing plants. They also come in a range of sizes, meaning they are suitable for a number of ornamental flowers as well as fruiting plants.
When Should I Water my Flowers?
Chrysanthemum plants have a shallow root system. This means that they require frequent watering especially during warm or dry periods.
Mulching around the plants helps to keep the roots cool. It also helps the soil to conserve moisture.
For a low maintenance option plant in self watering pots.
When watering try keep the foliage as dry as possible. Damp foliage is more likely to develop fungal problems.
How Frequently Should I Fertilize?
If you have purchased an annual chrysanthemum plant that is already in bud, it will not require fertilizing.
If you are growing the plants as perennials however, you will need to fertilize.
Fertilize from early spring until flower buds begin to form. This promotes lots of healthy foliage to form.
When the plants are developing new foliage apply a fertilizer rich in nitrogen and potassium. As well as encouraging lots of healthy foliage this also promotes the development of a robust root system.
Begin fertilizing as soon as any chance of frost has passed. This means that new growth promoted by fertilizing won’t be damaged by frost conditions. Continue to fertilize regularly until the plants begin to form flower buds, this is usually in June or July.
How much and how frequently depends on what type of fertilizer you choose to apply. Aim to apply a diluted 5-10-5 fertilizer several times before buds emerge. Alternatively a good application of slow release fertilizer can be given in early spring. This should last until early July, when buds are beginning to form.
How to Prune Your Plants
Some newer varieties do not require pinching out. However, most cultivars benefit from the practice.
Pinching out branch tips helps to create a sturdy, compact plant. As well as encouraging branching, pinching out also helps to prevent legginess.
Begin pinching out when new growth reaches 4 to 6 inches in length. Pinch about 1 inch from the branch tips two or three times during the growing season.
Removing the stem to the second set of leaves encourages low growth and prevents early flowering. Cut stems can be rooted and grown into new plants.
You should also pinch out any early flower buds. This encourages more flowers to form later in the year.
As a rule, don’t pinch out flower buds any closer than 3 months before the predicted flowering time. For example, if your plants predicted flowering time is in October, continue pinching out flower buds until mid-July.
Pinching out early flower buds helps to promote more profuse flowering later in the year.
Can I Overwinter my Chrysanthemum?
While chrysanthemum plants are commonly grown as fall flowering annuals, some varieties are perennial.
To overwinter in colder areas allow the top growth to remain in place. Cover the plants as best you can with a loose mulch such as straw. Alternatively, you can cover your plants with an insulating horticultural blanket. The Agribon Fabric Plant Cover insulates plants against potentially harmful frosts while still allowing light and moisture to permeate through to the soil.
Cut the plant back in spring and remove the mulch or cover.
Alternatively, once fall flowering has finished, lift the plant and cut it back. Store in a dry, frost free place such as a garage and replant in the spring.
Container plants can simply be moved undercover in the fall, once flowering has finished.
In warmer areas, where harsh frosts are unlikely, simply cut the plant back to about 6 inches in height once flowering has finished.
Chrysanthemum plants look particularly effective either on their own in a container or planted in combination with other fall flowers. Good companion plants include:
How to Propagate a Chrysanthemum
Taking divisions of perennial plants is the easiest way to propagate. Additionally, perennials should be divided once every two or three years. This helps to keep the plants healthy and promotes profuse flowering.
Division is best done in the spring as soon as new growth begins to appear.
To divide dig up the plant once new growth begins to appear. If you are digging up a larger plant you may need to use a shovel.
Carefully brush any remaining soil from the root section. You will notice that while the center of the root system is dying, the outer parts remain healthy.
Divide or separate healthy sections of the plant from the dying center. Each division should have a decent root section and some new shoots. Replant the divisions as quickly as possible. Discard the dying center.
Propagation via Cuttings
Cuttings can be taken in the spring or summer. This is the quickest way to get new plants.
With a sharp garden scissors, cut a healthy section of new growth just below the leaf node. The cutting should be 2 to 3 inches in length.
Remove foliage from the bottom half of the cutting and dip the cut end in rooting hormone if you are using it. Rooting hormone helps to promote root growth but is not necessary.
Plant the cutting in a small pot filled with either fresh potting soil, perlite or peat moss.
Place your cutting on a sunny windowsill and keep the soil moist. New growth should soon begin to emerge. Pinching out some of the new top growth encourages more lateral growth.
Once the plants have produced a healthy amount of new foliage and have established a root system they can be potted on or transplanted into a bed.
Growing From Seed
While it is rarely done, growing from seed is a pleasingly straightforward process.
Be warned, seeds are unlikely to grow true to the parent plant. This means that you never know quite what you are going to get. If you want exact replicas of the parent plant, propagate by cuttings or divisions.
As petals fall from the spent flower and the stem turns brown cut the flowers from the plant. On a plain surface or piece of paper remove the remaining petals from the flowers. As you do this the seeds also separate. If the seeds remain in the pod, carefully open the pod and remove them yourself.
Chrysanthemum seeds are small seeds, usually around 3mm in length. They are either dark brown or tan in color.
Alternatively cover the spent flowers in a small piece of fabric like cheesecloth. Tie the fabric over the flower.
Once the pod has split, cut the spent flower from the plant. Carefully open the fabric cover and remove the seeds. You may need to open the pod yourself to remove any stubborn seeds.
Allow the seeds to dry out in a bowl in a dark airy room. This can take around 4 days. Once dry seeds can be stored in a sealed bag or airtight jar, such as a Kilner jar. Keep the seeds in a dark place where the temperature averages 55 to 65 ℉. A warmer or light position can cause premature germination.
Chrysanthemum seeds do not keep well. Use as soon after harvesting as possible.
Sow your seeds undercover 6 to 8 weeks before the last frost. Place in a light position and keep the soil evenly moist. If you struggle to find a light enough position, try germinating the seeds under grow lights.
Following germination, allow the seeds to grow on before transplanting when they are 6 to 8 inches in height.
Seeds can also be sown outside in the spring. Sow into a well worked bed and cover with a light mulch. Keep the soil evenly moist.
Common Problems and How to Solve Them
Leaf spot, mosaic and powdery mildew can all target chrysanths. However, if your plants are correctly spaced and planted in a light location they should remain problem free. Keeping the foliage as dry as possible when watering also helps to prevent mildew.
As well as powdery mildew adopting good growing practices also helps to prevent rust and blights. Should your plant develop a problem, cut away and destroy affected foliage. Plants can also be treated with an anti-fungal spray.
Regularly check the foliage for pests such as caterpillars, spider mites, leaf miners and aphids. Should you notice any pests, wipe the foliage with some cotton wool soaked in neem oil or homemade insecticidal soap. This cures most infestations.
How to Encourage Flowering
Cutting back the plant in spring encourages branching stems to form. This provides more places for buds to form. These are hardy plants, don’t be afraid to cut back to about 2 inches above the ground.
Liquid fertilizer applied in early spring and pinching out early buds also encourages more flowers to emerge.
Fertilizing in the spring and deadheading spent blooms helps to prolong the flowering period.
Chrysanthemum plants are a popular way to add a late season pop of color to your garden.
Bright, colorful and easy to grow the chrysanthemum is a staple of the fall garden and it is easy to see why. The range of cultivars and colors on offer means that you are certain to find a plant or a combination of plants that will bring enjoyment and color to your garden.