Illustration
David Howard
Dahlia 'David Howard'
David Howard blooms from July through October.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing David Howard
Plant it in full sun. It prefers high water. It is hardy in USDA zones 8–10. Expect it to reach about 3 ft tall and 1.5 ft wide at maturity, in roughly 1 year (not yet checked).
What was checked
Mature height and spread, hardiness zones, sun and the trait tags were checked against named botanical sources for this plant. The bloom months and water need on this page were not, and each fact above says which. The planting, spacing and size sections are derived from these checked facts by a fixed rule, not checked separately, and the plant type is the library's own classification.
When to plant David Howard
David Howard is tender: plant it out after the last frost, once the soil has warmed. In zone 9, the middle of its hardy zones 8 to 10, that means February or March; where spring comes later, it goes out later. Expect flowers from July to October.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 9, the middle of this plant's hardy range, start with zone 9 in February. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does David Howard get?
3 fttall5 ft 7 inan adult1.5 ftwideSee David Howard in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
Where these facts come from
David Howard's height, spread, hardiness zones, sun and trait tags were checked against 13 published sources on July 31, 2026. Each one is linked below with every fact it carried, which can include a fact this page still marks as not yet checked, because a source carrying a value is not the same as the value being held to the standard. Facts not in that list, and the planting, spacing and size sections, are not covered by these sources.
- NC State ExtensionPlant Toolboxheight, spread, hardiness zones, sun, years to mature size and trait tags
- adrbulbs.comA.D.R. Bulbsheight, spread, hardiness zones, sun and trait tags
- Missouri Botanical GardenPlant Finderheight, spread, hardiness zones, sun and trait tags
- RHSRoyal Horticultural Societyheight, spread, sun, years to mature size and trait tags
- University of Florida IFASExtensionheight, spread, sun, years to mature size and trait tags
- BBC Gardeners' WorldMagazineheight, spread, sun and trait tags
- Fine Gardeningheight, hardiness zones and sun
- fleurfarm.comFleur Farmheight, sun and trait tags
- flowerfeatherfarm.comFlower Feather Farmheight, sun and trait tags
- University of Illinois Extensionhardiness zones, sun and trait tags
- bearcreekfarm.comBear Creek Farmheight and sun
- oldhousegardens.comOld House Gardensheight and sun
- University of Georgia Extensionsun and trait tags
How the checking works, and what each standard covers, is on the verified plants page.
Good to know about David Howard
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note.
Safety
Toxic to dogs, cats and horses, causing mild stomach upset and mild dermatitis. The leaves and tubers can also irritate skin, worse with sun exposure. per ASPCA and NC State
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Design a garden with this
Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.