Daisy

Which daisy you mean changes the answer

Daisy is one of the loosest common names in gardening. Three plants carry it in most American gardens and they behave differently.

Shasta daisy, Leucanthemum x superbum, is the border perennial with 2 to 3 inch white flowers on 2 to 4 foot stems. It is what this entry records, and what most people mean.

English daisy, Bellis perennis, is the small lawn daisy, a short-lived perennial grown as a bedding plant.

Oxeye daisy, Leucanthemum vulgare, is the wild roadside one, and it is listed as invasive or noxious in a number of states. It looks like a smaller, scruffier Shasta daisy, and it is worth telling them apart before moving one from a field into a bed.

Shasta daisy itself is a garden hybrid, developed in the 1890s near Mount Shasta in California, so it is not a native plant despite looking like a wildflower.

The daisies people actually search for

Beyond those three, half a dozen more plants are sold as daisies, and they are not variations on the same thing. They come from different genera, they differ in hardiness by six zones, and the care that keeps one alive kills another. This table is the shortest way to find out which one you have.

African daisy, which is three plants rather than one

This is the loosest name of the lot. The NC State toolbox lists African daisy as a common name for Arctotis and for Gazania rigens as well as for Osteospermum, and garden centers use it for all three. If you are buying by the tag alone, check the botanical name underneath it.

Osteospermum is the one usually meant. It grows 12 to 18 inches in full sun and moist, well-drained soil, and flowers from May through October in lavender, pink, purple, white, yellow and bicolors on glossy, slightly succulent foliage. It does well in containers, which is how most people grow it.

The one behavior that surprises people is what it does in summer. Osteospermum tends to stop blooming in real heat and pick up again when the weather cools, so a plant that goes quiet in July has not failed. Newer cultivars are bred for more heat tolerance and are worth seeking out in a hot climate. At the other end it takes light frost and keeps flowering, which makes it one of the better plants for a cool spring or a late fall container.

Marguerite daisy

A frost-tender shrubby daisy growing 2 to 3 feet, grown as an annual in most of the country and as a tender perennial where winters are mild. It flowers through the summer in white, pink and yellow, with double-flowered cultivars and some with blue-green foliage, and deadheading extends the display.

Its limitation is humidity rather than heat. It suits both dry and moist sites but declines in high humidity, and in hot climates it wants a sheltered spot with protection from afternoon sun. Bloom slows considerably in the peak of summer heat, in the same way Osteospermum does.

Painted daisy, and the insecticide in it

Painted daisy is the hardiest plant in the table after oxeye, perennial in zones 3 to 7, growing 1 to 3 feet tall and 1.5 to 2 feet wide with flowers in pink, red, purple or white around a yellow center in June and July. It wants full sun to partial shade and well-drained, moist, sandy to loamy soil, and it is deer resistant.

The detail worth knowing is in its other names: pyrethrum, pyrethrum daisy, and Persian insect flower. The flowers are the original commercial source of pyrethrins, the botanical insecticide that is still sold today. That is a matter of interest rather than a technique to copy, since extracting a useful concentration is an industrial process rather than a garden one, and pyrethrins are broadly toxic to bees and other beneficial insects as well as to pests.

Pinch back the new growth when the plant reaches 6 to 8 inches. It produces more stems and more flowers for it, and the pinched plant stands up better than the unpinched one.

Santa Barbara daisy

A low evergreen perennial under 12 inches, covered in small daisies from spring through fall, hardy to about 20°F. The flowers open white and age to a pinkish lavender, so an established plant carries both colors at once, which is most of its charm. It takes full to partial sun and well-drained, even sandy or chalky ground, and once established it is very drought tolerant, though it looks better with water through a hot summer.

The care that matters is restraint on its spreading. It seeds itself and also runs at the root, and in a mild climate it will take over a bed. Shear the whole plant to the ground in late winter and reduce the clump then; an occasional light shearing during the season encourages more flowering and cuts down the seed it sets. Deadheading is not otherwise necessary.

Daisy colors, and what the color tells you

Daisy blooms cover a much wider color range than the white-and-yellow default suggests, and the range maps closely onto which plant you are looking at. That makes color a useful shortcut for identification as well as for choosing.

• White with a yellow center is the default. Shasta, oxeye and Santa Barbara daisies are all white, and if a plant in the ground is white and hardy through winter it is almost certainly one of those three.
• Red, orange and salmon mean gerbera. No hardy garden daisy in this group produces those colors, so a scarlet or coral daisy in a pot is a gerbera and needs to be treated as a tender plant.
• Purple and lavender point to African daisy. Both Osteospermum and the marguerites reach into pink, but the true purples and lavenders belong to Osteospermum.
• Deep pink and red on a hardy perennial is painted daisy, which is the only reliably cold-hardy plant here that flowers in strong pink and red.
• The center disc is worth looking at too. Gerbera centers run from yellowish to nearly black, and a dark-centered daisy in a florist bunch is a gerbera almost by definition.

One caution on color that applies across the group: bicolors and dark centers are frequently deepened in catalog photography, and the flower in the ground is usually a shade or two softer than the picture that sold it.

Growing daisies from seed

Which daisies come from seed sensibly depends on whether the plant is a species or a hybrid, and that distinction decides more than any technique does.

Oxeye daisy sets seed abundantly, up to 200 seeds per flower head, and also spreads by underground rhizomes. That is exactly why it is listed as invasive in a number of states, and it is the reason not to bring one home from a roadside. If it is already in a garden, deadhead before the seed sets rather than after.

Shasta daisy is a garden hybrid, raised near Mount Shasta in the 1890s, so seed from a named cultivar does not come true. Seed-raised plants are a lottery on flower size and form. Division every two to three years, which the plant needs anyway, is both the reliable way to increase it and free.

Gerbera daisy seed loses viability quickly, which is the practical obstacle rather than germination itself, and gerbera seedlings are slow to reach flowering size. The one thing that decides whether a young gerbera lives is planting depth: set the crown at or slightly above soil level, never below it, because a buried crown rots.

Daisy seedlings in general are small and slow, and the common mistake is treating them like the mature plant. A seedling has no root system to draw on, so it wants steady moisture and shelter until it is established, and only then the leaner, drier treatment that suits the adult plant.

Does gerbera daisy need full sun?

Less than the name suggests, and this depends on where you garden. Clemson recommends morning sun and afternoon shade rather than full sun, because the intensity of southern afternoon heat is more than the plant wants. Further north, full sun is fine.

The rest of gerbera care follows from the crown being the vulnerable part. Grow it in well-drained soil rich in organic matter, use containers or raised beds where drainage is poor, and let the crown dry out between waterings. Avoid overhead watering entirely, since wet foliage brings on the fungal problems the plant is prone to, and water early in the day so anything that does get wet dries. It is hardy in zones 8 to 10 and treated as an annual elsewhere; a plant brought indoors wants 45 to 50°F and very little water.

What it wants

Hardy in zones 5a to 9b, growing 2 to 4 feet tall and 1 to 3 feet wide.

Full sun at six hours or more, or partial shade at two to six. In shade the stems stretch and the plant leans, which is the usual reason a clump falls open in the middle.

Soil can be clay, loam, sand or high organic matter, at acid to neutral pH, wanting good drainage and tolerating moist or occasionally dry conditions. NC State adds the qualifier that matters most: it is intolerant of winter wet.

That single condition explains most Shasta daisy losses. The plant survives cold perfectly well and rots in ground that stays saturated from November to March. In heavy soil it belongs on a slope or in a raised bed.

Keeping it going

Shasta daisies are vigorous and short-lived, which is a combination that catches people out. A clump that was magnificent in year two is thin and woody in the middle by year four.

1. Divide every 2 to 3 years

   NC State’s interval, and it is not optional maintenance. Lift the clump in spring, discard the woody center and replant the vigorous outer sections.

2. Deadhead through the season

   Removing spent flowers encourages reblooming and extends what would otherwise be a short June to August window.

3. Support the tall cultivars

   Four-foot stems carrying wide flat flowers go over in rain. Grow-through supports put in early are invisible by June.

4. Do not enrich the soil heavily

   Rich ground gives soft tall growth that flops. This is a plant that performs on ordinary soil.

5. Cut back after flowering

   Taking the whole plant down once flowering finishes keeps the foliage tidy and reduces the leaf spot that builds up on old growth.

Which Shasta daisy to buy

Cultivar choice settles two of the three problems below before they start, because the differences between them are in stem strength and disease resistance rather than in looks.

• Becky is the one to buy if there is only going to be one. It reaches 3 to 4 feet with flowers 3 to 4 inches in diameter, its stems are rigid enough not to need staking, and it has excellent resistance to phytophthora, which is the root disease that accounts for most losses on this plant.
• Alaska is the cold-hardy standard at 2 to 3 feet with 3 inch flowers, blooming July into August, and its stems are also stiff enough to stand without support.
• Crazy Daisy is the frilled double, 2 to 2.5 feet with twisted, quilled white rays on 2.5 inch flowers from June to August, hardy to zone 4 and carrying several flowers per stem. Worth noting against the point below on pollinators: a double flower like this feeds far less than a single.

Whichever you plant, the winter drainage rule still applies. No cultivar in this group survives soil that stays saturated from November to March.

What goes wrong

NC State lists aphids, leaf miners and spider mites among insects, and verticillium wilt, leaf spot, powdery mildew, stem rot and phytophthora among diseases, noting that resistance varies by cultivar.

Leaf miners are the visible one: pale winding tunnels inside the leaf. They are cosmetic on an established plant and picking off affected leaves is enough.

The serious pair are the root and crown problems, stem rot and phytophthora, and both trace back to the same cause as the winter losses: ground that holds water. Verticillium wilt is soil-borne and incurable, showing as one side of the clump wilting while the rest looks healthy.

The complaint that is not a disease is a clump that has gone thin and sparse in the middle. That is age, and division is the answer.

Two more symptoms come up often enough to name, because both are read as disease and neither is.

• Flopping stems after rain. A four-foot stem carrying a wide flat flower head goes over under the weight of water, and it does so most on plants growing in rich ground or in too much shade. The fix is cultural rather than a treatment: ordinary soil, full sun, supports set early, and a shorter cultivar where the site is exposed.
• A short flowering season. Shasta daisy flowers June through August, and a plant that finishes in five weeks has usually not been deadheaded. Removing spent flowers as they go over is what extends the display; leaving them on tells the plant its work is done.

On the tender daisies the diagnosis runs the other way, and it is worth stating because it accounts for most of the gerbera and African daisy that people lose. On gerbera the problems are gray mold, powdery mildew and anthracnose, and all three follow moisture sitting on the plant, along with whiteflies, aphids, thrips and spider mites on the foliage. On Osteospermum and marguerite the usual complaint is not a disease at all: a plant that stops flowering in midsummer is responding to heat and will resume when it cools.

What it brings

NC State records that the plant attracts butterflies, bees and other insects.

The flat open flower is the reason. A wide landing platform with an accessible center suits a much broader range of insects than a deep or double flower does, which is worth remembering when choosing between a single Shasta daisy and one of the frilly double cultivars. The doubles look impressive and feed far less.

Toxicity, in plain terms

NC State describes Shasta daisy as mildly toxic if ingested, causing hypersalivation, mouth irritation, vomiting and diarrhea, and notes it can cause skin irritation and contact dermatitis.

This is a plant that makes an animal briefly unwell rather than one that puts it in danger. Gloves handle the dermatitis question for anyone who reacts when dividing or cutting back.

Frequently asked questions

Why did my Shasta daisies die over winter?

Almost certainly winter wet rather than cold. NC State describes the plant as intolerant of winter wet, and it is hardy to zone 5. In heavy soil it needs a slope, a raised bed or improved drainage.

Why has the middle of the clump gone bare?

Age. Shasta daisies are vigorous and short-lived, and the center goes woody within a few years. Divide every two to three years, throw the middle away and replant the outer growth.

Why do the stems flop?

Too little sun, too rich a soil, or a tall cultivar with no support. All three produce soft stems that cannot carry a wide flat flower through rain.

Is the daisy in my lawn the same plant?

No, that is English daisy, Bellis perennis, a much smaller plant. The roadside one is oxeye daisy, Leucanthemum vulgare, which is listed as invasive or noxious in several states and is worth identifying before bringing into a garden.

Are daisies poisonous to pets?

Mildly. NC State lists hypersalivation, mouth irritation, vomiting and diarrhea if eaten, plus possible skin irritation from handling. Unpleasant rather than dangerous.

Companion plants