Common names: Chrysanthemum, Mum, Pellitory
Chrysanthemum is a derivative of two Greek words, chrysos or ‘gold’ and anthemon or ‘flower’. For the past fifteen years, or forever it seems to confused gardeners, botanists have been arguing about the naming of this plant family. Mum is an obvious derivative of chrysanthemum.
Pellitory comes from the Latin parietarus meaning ‘belonging to the walls’. Some old forms of Chrysanthemum were typically found growing in cracks in rocks and in the cracks of stone walls.
Gardeners still call them Chrysanthemums but botanists have now separated them into Leucanthemum, Tanacetum, and other more scientifically appropriate names. I’ll describe them as described by the most recent information I have, and the botanists will likely find another reason to rename the entire family by the time you read this.
- Bloom time: Early summer to midsummer
- Height:12” to 40”
- Sun needed: full sun to light shade
- Bloom color: Yellows, whites, shades of red
- Planting space: 12” to 24” apart
- Soil preferred: Well-drained but high in organic matter.
- Propagation method: Division, cuttings, seeds
Leucanthemum x superbum or Shasta Daisy as it is more commonly known. (Formerly Chrysanthemum superbum) This is the white-flowering daisy that we all love to have in our gardens. If it is kept reliably dead-headed (the blooms removed as soon as they start to wilt) then it is the longest-blooming daisy in the garden. It will tolerate more shade than most of the other plants described here so a bit of experimentation is in order. The shorter forms will take more shade than the taller but if the blooms are not heavy or the stalks are flopping, then the plant is not receiving enough sunshine. It is important to deadhead or shear these varieties after blooming to encourage a second or third flush of blooms.
- ‘Alaska’ is the old 36” standard form. Easy to grow and reliable.
- ‘Little Miss Muffet’ and ‘Little Princess’ are both 12 to 18” tall and heavy bloomers.
- ‘Snowcap’ 14” plants and mounds of white blossom from early to late summer. A classic plant and well worth growing.
- ‘Summer Snowball’ a tall 30” variety, double-white flowers from early to late summer if you deadhead. Even though it is tall, it tolerates winds and heavy rain quite well unlike some other fully double flowers that fall over.
Tanacetum coccineum (formerly Chrysanthemum coccineum) or Painted Daisy. This old-fashioned flower brightens up any cottage garden. It can be floppy so it is best planted in masses or next to other flowers that will hold it upright. If you deadhead this variety regularly, it will be encouraged to produce extra flowers. The one disadvantage to this plant is that it can be short-lived. Some gardeners say that regular dividing and encouraging new growth keeps the plant alive much longer. This plant is easy from seed and can be easily started by beginning gardeners. The ‘Robinson Hybrids’ and ‘James Kelway’ are the most commonly available forms both in nurseries and in seed catalogs.
Tanacetum parthenium (formerly Chrysanthemum parthenium) or Feverfew. This small-flowered daisy has large numbers of blooms in bunches on the ends of tall stems. They are quite aromatic and like many of the mum family, they will be much more bushy and attractive if they are pinched back to half their height in mid- to late June. The rule of thumb in our garden is that when the plant gets to one foot in height – pinch. This might be early June in a warm year or late June in a cooler summer. The one-foot rule works no matter where you garden. In our gardens, these have been short-lived perennials but with any luck at all, they self-sow. A well-drained soil is absolutely essential if you want this plant to overwinter; clay is a killer. Varieties include
- ‘Aureum’ a yellow-tinged-green foliage with white flowers containing a yellow eye.
- ‘Double White’ has small pom-pom buttons of flowers.
- ‘Golden Ball’ is a yellow button flower form with compact growth habit. One of the better forms.
Most of this related plant family does best in full sun. While some of the shorter and thicker-stalked plants will grow in light shade, they do tend to get floppy in shadier gardens. They are plants of open meadows and resent standing water. They resent it so much that their lifespan is much shorter in clay soils than in sandier ones. Overfeeding tends to produce floppy plants so a single spring application of compost is adequate for the season’s growth.
Potions and Poisons
Culpepper in his herbal tells us that this plant is a fine purge for the brain (whatever that does). It has also been used for toothache, a snuff to clear the head, and when used as a gargle, it is reputed to ease the partial paralysis of the tongue. This is not likely going to hurt you but it is not recommended for use without a physician’s supervision.
Blooming Too Early?
If your mums are blooming too early, the cause is a simple one – stress. And in this summer season, we’re about to blame heat stress and (maybe) water stress.
Water stress normally causes early blooming when the plant is quite young. So if we have a dry spring and you don’t get out the hose – or if you’re growing in a container and go light on the water, then water stress is going to kick the plant into bloom early.
The most likely culprit this year for much of North America will be heat stress. The heat of this summer has stressed many plants and we’re starting to see the results this fall.
What can you do about it?
Well, you could take a stiff drink and sit on the porch admiring the early blooms. But there’s nothing you can do once the bloom starts to initiate; the plant’s in charge then.
If you don’t deal with the stress early, you get to enjoy the blooms – early too.
Fall Blooming Tips
OK, so it’s garden mum time and you may be experiencing some difficulties in getting them into bloom.
One of the things many gardeners don’t understand is that this plant is very much controlled by temperature and light levels. Fall mum flowering is primarily controlled by fall-type environmental variables. As the daylight levels decrease because of shorter days, the buds are initiated. And as night temperatures drop, bud initiation is initiated. So – cooler nights and lowered light levels kick mums into bloom.
Last year (you may remember) August was cold and the mums bloomed early. This year, it’s been hotter and the mums are hanging on later.
Here are a few techniques that might help you with timing on your mums. While this isn’t particularly a problem in the garden, it can be a big problem if you’re trying to grow and flower those mums in containers.
If you need to push them along – to get them into flower faster, you want to increase feeding of nitrogen but particularly of “ammonium” based forms. This is clearly not “organic” but you’ll get a good boost if you use a fish-emulsion fertilizer that tends to be readily soluble and readily used by plants.
Do not use urea-based (common household fertilizer) as this pushes the leaf growth along and not the flower development. You’ll know you’ve done this when you see soft leaf or stem growth shoot up over the developing buds and the buds are being hidden by this growth.
In the nursery, we used to use what we called “constant liquid feed” and this meant that every time we watered we fed our plants. Feeding a weak solution of plant food at every watering meant our plants kept on developing no matter how much water we had to put onto the pots (remember when you water, you drive soluble nitrogen out the bottom of the pot so if you don’t replace it, your plants will not be fed). If you do this, try cutting back the plant food to zero once or three times a week (every second watering) to “shock” the plants and get them into bloom.
This is a tricky one. If you keep your plants constantly wet, then they’ll constantly grow. Combined with a good feeding regime, you may have some difficulty bringing those mums into a decent bloom because they want to really, really grow (and overgrow the buds).
The trick here is to allow the pot to dry out “slightly” between waterings. Not let them wilt exactly, but not keep them happy with the amount of water either. A “just” starting to wilt is OK (as in the buds just looking like they may wilt but not bent right over) I confess this is a “feel” kind of thing but you’ll know you’ve let them get too dry if you see the buds laying over and/or some leaf burning (dry conditions along with too much plant food will burn leaves).
Also – put your water on in the mornings. Do not water at night. A plant does most of it’s vegetative growth at night so reducing the amount of water at night will slow the plant down. This works for all plants by the way.
So. By altering the amount you feed and by altering the way or timing you water, you can either bring a mum into bloom faster or delay that bloom time.
You might want to mess about with some experiments in your garden by feeding some mums heavily or allowing others to wilt a bit so see what happens. Each gardener is going to have their own watering style and will have to adjust it for the plants being grown. (it’s why we call it advanced gardening) 🙂 And you’ll only learn by messing about in your own garden.
Chrysanthemums Sold As Houseplants
These are generally not considered hardy north of a USDA 6. Trying to grow them outdoors is just not going to work in the average garden.
One trick you might try (but it comes with absolutely zero guarantees) is to
- Plant your mum in the garden (in the fall after it finishes blooming in the house.)
- Mulch it like crazy with at least 6-inches of mulch.
- If it doesn’t rot with spring freeze-thaw and excessive moisture, it may throw a few shoots the following spring
A second technique is to grow them indoors on a sunny windowsill for the winter treating them as an annual.
- They will become long, leggy and quite ugly.
- Take cuttings in the spring – they root easily
- Grow outside as any other mum but don’t expect them to live. Unless you dig them up and repeat the process indoors
Or – simply treat them as annuals and enjoy them while they’re in bloom (and then give them to somebody else to kill) 😉