The chrysanthemum is an attractive plant that creates profuse, attractive blooms. When grown alongside flowering perennials, it will add color to your garden well into fall. These flowers come in a range of colors, shapes and sizes, and there’s a chrysanthemum for every garden and container. From selecting your plants to watching them bloom, this guide will help you get the best out of your mums every step of the way.
Chrysanthemum Varieties
Most varieties are classed as tender plants. They can be either hardy or half hardy depending on the variety and growing conditions. Chrysanthemums are suited to growing outdoors in USDA zones 5-9. Elsewhere, grow them indoors or in greenhouses where you can better control conditions.
There are a number of different varieties available, so take your time to find some that you really love.
Decorative Spray Chrysanthemums are a popular variety, often grown outdoors. They’re attractive in containers or garden beds, and they also provide scores of long-lasting cut flowers.
Varieties include:
- Bruno Bronze
- Payton Lady Purple
- Pennine Ski White
- Payton Blaze Red
Outdoor Bloom Chrysanthemums are the flowers you’ll see most often in florist shops. These produce attractive large flower heads, and are best grown in borders or raised beds.
Varieties include:
- Tom Pearce Red
- Creamist White
- Regal Mist Purple
- Creamist Gold
Hardy Garden Mums are a free branching, bushy variety, and pinching out encourages its copious flowering habit. They’re ideal for containers and borders, and are fully hardy. As a result, they’ll flower until the first frosts.
Varieties include:
- Padre Red
- Aluga Yellow
- Amiko Violet
- Conella Orange
Late-Flowering Chrysanthemums grow best in greenhouses, or locations where they’re sheltered from frosts. They’ll flower from late October until early winter, so they provide attractive, late-season color. They’re also great cut flowers, just like all other chrysanthemums.
Varieties include:
- Spider bronze
- Cobra Yellow
- Froggy
- Jaguar Red
If space is at a premium, try a dwarf variety such as Fanfare Improved Hybrid F1. This plant provides you with attractive flowers that can decorate containers or vases.
Planting Chrysanthemums
Gardeners rarely grow chrysanthemums from seed. Instead they’re purchased as young plants.
As soon as you get your plants, check the soil. Water dry plants with a fine spray or sit them in a shallow tray of water. Plant chrysanthemums as soon as possible. Within 24 hours is preferable.
Growing on Plug Plants
Carefully remove the plant from its container. Try to handle each plant by the root ball to avoid accidental damage to the stem.
Pot each plant in a clean 3 inch container filled with fresh container or multi purpose compost. Water in and place in a bright, frost-free location to grow on for a couple of weeks. During this period, keep the soil moist, but not overly wet, and ensure that the plants are not in direct sunlight. If cold weather is forecast put the plants in a covered location or protect with a horticultural fleece.
As the weather warms up, slowly harden off the chrysanthemums. From mid May on, when the plants are acclimatised and the last local frost date has passed, replant the flowers in their permanent position.
Positioning Chrysanthemum Plants
Chrysanthemums do best in sheltered, sunny locations with rich, well-draining soil.
Before planting improve the soil by digging in well rotted organic matter. About 25lbs per square yard is ample. This is best done in the winter months as it gives the soil time to resettle before you plant.
In addition, you can add a dressing of general-purpose fertilizer, such as fish or bone meal, in April, just before you plant. Work in about 4oz per square yard.
Plant chrysanthemums to the depth of the pot, spacing 8-18 inches apart. More vigorous varieties require more space.
Watering regularly for 2 weeks after planting will help the plants to establish themselves.
Caring for Chrysanthemum Plants
Once established, chrysanthemums are fairly low-maintenance plants.
Watering and Feeding
Water chrysanthemums regularly, and don’t allow the soil to dry out. Reduce watering during rainy spells.
If you’ve prepared the beds or containers before planting, you don’t need to apply additional feed. However, a nitrogen-rich top dressing, applied in June, encourages healthy growth. Apply about 1oz per square yard of sulphate of ammonia. If you want an organic alternative, work in 2oz per square yard of dried poultry manure pellets.
Weeding, Pruning and Disbudding
Weed around your chrysanthemums regularly, as weeds can sap moisture and nutrients, stunting plant growth. Pruning brown or damaged leaves helps to prevent pests and diseases from spreading. Regular deadheading also encourages more flowers to form.
Pinching out and Disbudding
Some varieties may require pinching out. This is the process of stopping, or pinching out, the growing points. It’s usually done in late May or early June, and encourages the plant to branch out instead of getting leggy.
The large single blooms of the chrysanthemum are sometimes called disbuds. These are encouraged by maintaining the central bud and removing side buds and shoots. Consequently only one, the terminal flower bud, remains on each shoot. Alternatively, removing the terminal flower bud from spray cultivars encourages large spray formations to emerge.
Optimum pinching out and disbudding times varies between cultivars. You’ll find the information on the label or in the plant catalogue.
Staking
Chrysanthemum stems tend to break, especially if the plant is heavy with flowers. Since this is a fall-flowering plant, their heaviest period often coincides with winds and rain. This makes staking necessary. Choose stakes that are tall enough to support the plant, but not so tall that they’ll overshadow the flowers.
Overwintering
Once flowering has finished, cut the main stem down to about 8 inches.
Many early chrysanthemums are hardy enough to survive temperatures of 23F. These can be left in place if you’re growing in milder climates. Just provide them with a good covering of protective mulch such as compost or wood chips.
In colder climates, or if you’re growing less hardy varieties, your plants will need to be lifted. Chrysanthemums in exposed positions should also be lifted. After carefully lifting the plant ,shake the soil from the roots. Remove any remaining green shoots and leaves from the stem.
Once lifted, all chrysanthemums tend to look alike. Be sure to label yours so you can identify your plants the following spring.
Fill a shallow tray with about 2 inches of fresh, multi-purpose compost. Place the plants in the tray and lightly cover the roots. Store in this condition in a cold but frost-free location such as a greenhouse or conservatory. Check the soil regularly throughout the winter to ensure it remains moist and doesn’t dry out.
Growing Chrysanthemum Plants Indoors
Some varieties, such as Porto Purple and Anastasia Green, grow best indoors. These flower from late November until early January. Most chrysanthemum varieties are versatile enough to grow either indoors out outside with the proper care.
Plant rooted cuttings straight into the beds, spacing about 14 inches apart depending on the variety. Water in well. Pinch out and stake as you would outdoor varieties.
Growing Chrysanthemum Plants in Containers
Fill a 13- to 15-inch container with fresh, potting on compost. Plant one cutting or plant per pot and water in well. Stake if required and pinch out as you would outdoor plants.
After the last local frost, place outside in a sunny, sheltered position. Keep plants watered. Apply a balanced feed every 2 weeks from midsummer until flowering begins.
Return the plants to their covered location in early fall, before winds can damage them. Once flowering is finished cut the plants back and overwinter in a frost free location.
Propagating Chrysanthemum Plants
You can propagate chrysanthemums in several different ways.
Cuttings
This is the most reliable method of producing strong, healthy plants.
In early January take the over-wintered plants into a moderately heated conservatory (45-50F) or greenhouse. Keep the soil moist, and within 4 weeks you’ll notice shoots emerging from the base or crown. These will grow into strong, green shoots.
From mid February on, harvest these shoots as cuttings. Each cutting should be about 3 inches in length.
Once the cutting is taken, pot it in a small container of fresh compost and place in a light, sheltered location at 50F. From here, the cutting will grow into a young plant.
Division
Divide harvested roots, or stools, with a sharp clean knife when they get too large, or become old. The best time to do this is in the spring, when you are replanting after over-wintering.
Seeds
Some varieties, such as cascade, can be grown from seed. Sow the seeds at 59F, and you should see germination occur within 2 weeks. Following germination, grow the plants on as you would cuttings or plug plants.
Common Pests and Diseases
Chrysanthemums can fall victim to a number of pests. The most common are aphids and leaf miners. You can easily remove these pests with a blast of water from a hosepipe. Cutting away damaged or affected leaves also stops the spread.
Capsid bugs and glasshouse red spider mites may occasionally attack plants. Adopting good growing practices, such as planting correctly, regularly weeding and not over-watering will reduce the chances of attack.
Diseases
Rust diseases such as white rust can be damaging to plants, and it’s also difficult to stop. It causes pale yellow spots to emerge on the leaves’ surface, and as the disease progresses, leaves shrivel and turn brown. Growth will also be stunted and pustules may develop on other leaves and flowers.
Chemical fungicides can help to stop the spread of rust diseases. However, organic solutions and good growing practices—including promptly removing any damaged leaves—are just as effective.
Powdery mildew may appear in overly dry conditions. In contrast, grey moulds and fungal rot can strike in wet conditions. Correctly spacing the plants improves air circulation, which deters mould and mildews. During wet periods, reducing or stopping watering altogether can decrease chances of the roots becoming too wet and rotting.
Chrysanthemum Companion Plants
Bright, colorful chrysanthemums make great companion plants. Classic bedding plants, such as violas, pansies, snapdragons, gerbera daisies, dianthus, coneflowers, and bracteantha or straw flowers all compliment chrysanthemums beautifully. Many, such as straw flowers, also enjoy similar growing conditions.
Foliage providing plants such as heuchera work nicely as a backdrop to showy chrysanthemum varieties.
Vegetable Options
Tomatoes may not be an obvious choice for a chrysanthemum companion plant. However, some varieties can protect tomatoes, as well as other vegetables and ornamentals, from pests. For example, coccineum kills root nematodes while cinerariaefolium flowers produce pyrethrin: an insecticide that repels many common pests.
In addition, white chrysanthemums can deter Japanese beetles. As a result, they’re helpful companions to roses and grapes, which these pests love to target.
Planting chives with your flowers will deter aphids and other unwanted insects as well.
There aren’t any combinations that you should avoid, but be careful when planting bedding plants near chrysanthemums. Tall, bushy varieties may block out light, preventing or stunting bedding plant growth.
Hardy, long-lasting chrysanthemums are a popular way of adding late summer and fall color to your garden. Best of all, the chrysanthemum’s many different shapes, sizes, and hues mean that there really is a variety for everyone.
