Shrub · Rosaceae
Grandiflora Rose
Rosa
Tall, long-stemmed, and built to bloom from spring to frost, the grandiflora gives you hybrid-tea flowers on a floribunda frame.
Full sun
Every 4–7 days
USDA 5–9
4–6 ft · 1.2–1.8 m
Overview
The grandiflora storms into a garden as one of the taller modern roses, born in 1954 from a cross of hybrid tea and floribunda. That pairing handed it the shapely, high-centered flower of the hybrid tea and the tall, clustered habit of the floribunda, so one plant churns out cutting-quality blooms one to a stem or in full sprays. Queen Elizabeth launched the whole class and still anchors gardens everywhere.
These sun-chasing shrubs climb to 4 to 6 feet and keep firing off flowers from May clear to frost. They do want a bit of attention, chiefly steady water at the roots and one bold pruning each late winter, and they pay it back with months of nonstop color. Hand them room and moving air and they power along far healthier.
Mind the thorns, and you are golden. Grandifloras bristle with sharp prickles down every cane, so gloves and long sleeves pull their weight at pruning time. The plant itself stays safe around pets and people, with no toxin in the mix, so it is a joy to grow.
Care
The short version: load it with full sun for at least six hours, plant it in slightly acidic, well-drained soil packed with compost, water deep at the base each morning, feed it monthly through the growing season, and cut it back hard in late winter.
Light
Pour on full sun, six hours or more a day, and a grandiflora blooms its heart out. It shrugs off a touch of partial shade, but dimmer light trims the flower count and invites disease as the leaves cling to moisture longer.
Water
Water it deeply and on a steady rhythm, best in the morning so the leaves dry off by evening. Soak the root zone and skip splashing the foliage, since wet leaves are the launchpad for black spot and mildew. Hold even, medium moisture every 4 to 7 days.
Soil
Plant it in well-drained loam, slightly acidic and loaded with organic matter. A pH of 6.0 to 6.5 hits the mark, so churn in plenty of compost before planting and the roots dive deep while the plant powers up.
Temperature
Grandifloras are surprisingly tough, taking on conditions from -20°F to 95°F (-29°C to 35°C) across their hardy range. They laugh off real cold once established, though a brutal summer heat wave can wear the blooms down.
Humidity
Everyday outdoor humidity does the job, so there is no number to chase. Airflow is the real player here, because still, damp air trapped around crowded canes is exactly the buffet the fungal diseases want.
Feeding
Feed monthly through spring and summer with a balanced rose fertilizer while the plant charges ahead. Back off as the season fades, and go easy on the nitrogen, which pumps out the soft growth aphids and mildew love.
Pruning
Cut it back hard in late winter to early spring, taking the canes to roughly 12 to 18 inches from the ground. Rip out anything dead, weak, or crossing, then deadhead spent blooms all season to keep fresh flowers rolling in.
Repotting
Grandifloras thrive in the ground, not pots, so repotting barely enters the picture. If one lives in a container, bump it up a size the moment roots circle the pot or shove through the drainage holes and blooming stalls.
Size & spacing
Count on a plant 4 to 6 feet (122 to 183 cm) tall and 2 to 3 feet (61 to 91 cm) wide. Give each one enough space for air to sweep freely between the canes, your sharpest defense against leaf disease.
When to plant
Grandifloras run on the calendar, so play the seasons and they deliver. Pop new plants in the ground in early spring once hard frost clears out, or in fall where winters stay mild, then watch for that first burst of bloom in May and a nonstop parade of flowers right up until frost calls it.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: early spring after the threat of hard frost, or fall in mild climates
- Harvest: May to frost
Hardiness
USDA hardiness zones: 5–9
Temperature: down to -29°C
Troubleshooting
Almost every rose hiccup lands on the leaves and the soft new growth, and most of it circles back to wet foliage or crowding. Spot the early signs and jump on them, and a small snag never gets the chance to spread. Match what you see below, then move while it still turns the tide.
Dark spots marching up from the bottom leaves as they yellow
Spot those dark marks and you have met black spot, the fungus roses tangle with more than any other, and it kicks off low on the older inner leaves. Wet foliage hands it the door, so aim your morning water right at the base, pluck off every marked leaf, and sweep up the fallen ones. Open the plant up with a few smart cuts so light and air pour through, and reach for a fungicide when the pressure spikes. Stay on it and the rose bounces right back.
Fix:
- Remove and dispose of infected leaves and fallen debris
- Water at the base in the morning and keep foliage dry
- Improve air circulation by proper spacing and pruning
- Apply a labeled fungicide preventively if disease pressure is high
A dusty white bloom on the new growth with young leaves curling
That dusty white bloom on the fresh growth is powdery mildew, and it pounces when warm days flip to cool, humid nights. Snip out the shoots it has hit hardest, throw open more sun and breathing room, and dial back the nitrogen that keeps feeding all that soft new growth. Where it digs in, a labeled fungicide or horticultural oil clears the deck and gets the plant humming again.
Fix:
- Prune out heavily infected shoots
- Improve air circulation and sun exposure
- Avoid excess nitrogen that pushes soft growth
- Apply a labeled fungicide or horticultural oil when needed
Soft insects swarming the buds and coating them with sticky film
See soft little bugs swarming the tender shoots and you have found aphids, whose sticky honeydew can turn black with sooty mold. Blast them off with a sharp jet of water, then chase down the holdouts with insecticidal soap or horticultural oil. Better yet, roll out the welcome mat for lady beetles and lacewings, which hunt aphids all day long, and keep the nitrogen in check so you stop serving up the soft growth they crave.
Fix:
- Dislodge aphids with a strong spray of water
- Apply insecticidal soap or horticultural oil to affected growth
- Encourage natural predators such as lady beetles and lacewings
Toxicity
Here is the fun part: true roses are non-toxic to pets and people alike, so a curious nibble from a cat, dog, or rabbit sparks no poisoning at all. The petals and hips even land on the table. The only real hazard is mechanical, those sharp thorns down the canes, so just handle the plant with a little care.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Let a cat prowl the rose bed freely, since the ASPCA marks true roses non-toxic and a nibbled leaf or petal poisons nobody. Keep an eye on the thorns, though, because a sharp one can catch a curious paw or mouth.
Dogs None
A dog can nose around a rose with zero poisoning risk, foliage and all. Just scan the nose and paws for the odd thorn scratch.
Horses None
Horses ride along on the ASPCA's safe list too, so browsing the leaves does no harm. Only the prickly canes give any trouble, snagging now and then on the lips.
Rabbits None
Rabbits munch rose leaves and petals with no worries, and plenty of gardeners toss them a few as a treat. Just yank the thorns off any cuttings before they get one.
Livestock None
Goats, sheep, and cattle browse rose foliage without a hint of poisoning risk. The sharp prickles running the canes are the only snag.
Birds None
Birds get nothing but good from a rose, and the hips make a welcome winter feast for loads of wild species.
People None
Rose petals and hips land happily in teas, jams, and syrups, all of it edible. The thorns are the lone catch, so pull on gloves before you dive into pruning.
Most grandiflora roses bear sharp thorns (prickles) on the canes that can cause scratches and puncture wounds; the hazard is mechanical, not chemical. Wear gloves and long sleeves when pruning or handling.
Varieties
Only a handful of grandifloras show up in most gardens, and these are the standouts worth chasing down by name.
Queen Elizabeth
The trailblazing first grandiflora ever released, this upright grower shoots to 4 to 6 feet and throws double silver-pink blooms both singly and in long-stemmed clusters.
Gold Medal
A tall grandiflora that wins fans with golden-yellow, hybrid-tea-shaped flowers riding long stems that beg to be cut.
Tournament of Roses
A vigorous, disease-shrugging grandiflora that pumps out coral-pink double blooms in generous clusters.
Companions
Grandifloras do best beside aromatic plants that confuse pests and share their love of sun and good drainage, and worst anywhere near a black walnut.
Plant near
garlic: Aromatic alliums interplanted near roses are a traditional companion thought to help deter aphids.
lavender: Drought-tolerant, sun-loving companion that shares full-sun, well-drained conditions and attracts pollinators without crowding roots.
Keep apart
black walnut: Black walnut releases juglone, which can harm many garden plants; keep roses away from its root zone.
How to propagate
Roses multiply a few different ways, though some demand way more skill than others. Here is how each method works and what to expect from it.
GraftingDemanding
Late summer for budding onto rootstock · One growing season
This is the trick nurseries pull to keep named grandifloras true to type, budding a scion onto a hardier, disease-resistant wild rose rootstock in late summer. The new plant digs in over a single growing season. It rewards a practiced, steady hand, so most home growers hand this one off to the pros.
Stem cuttingsModerate
Late spring through summer from semi-hardwood growth · Several weeks to a few months to root
Grab cuttings from healthy, current-season stems anytime from late spring through summer, once the growth firms into semi-hardwood. Rooting runs from a few weeks to a few months, and the cultivar largely calls the shots on how fast it takes. Just remember that patented varieties cannot be legally propagated.
LayeringModerate
Spring to summer while canes are flexible · One season for roots to form
While the canes still bend easily in spring or summer, pull a low one to the ground and bury a stretch of it. Roots take hold over a season where the buried wood presses into moist soil, and then you snip the new plant free and plant it wherever you like.
Myths
Roses are poisonous to cats and dogs.
Toss this worry out, because the ASPCA lists true roses in the genus Rosa as non-toxic to cats, dogs, and horses, so a chewed leaf or petal poisons no pet. A scratch from the thorns is the only real risk. Just keep an eye out for imposters that borrow the rose name, like desert rose or Lenten rose, since those can pack a toxic punch.
Grandiflora is a botanical species of rose.
Grandiflora is a garden class, not a species. Breeders cooked it up in 1954 by crossing hybrid teas with floribundas, welding the shapely hybrid-tea bloom onto the tall, clustered habit of a floribunda.