Ornamental · Malvaceae
Hollyhock
Alcea rosea
Tall, old-fashioned spires of bloom that plant themselves once you let them go to seed.
Full sun
Every 5–7 days
USDA 3–9
5–8 ft · 1.5–2.4 m
Overview
Hollyhocks are the cottage-garden classic, and they are a wonderfully welcoming plant to start with. Their flower spikes can climb past 8 feet (244 cm) to line a fence or a back wall in summer color, and they belong to the mallow family that has cheered dooryards for generations. What people love most is the way those saucer-shaped blooms march up a single tall stalk from June through August.
Do not let the height fool you into thinking they are fussy, because they truly are easy to grow. Most are biennials, so a plant spends its first year building a low rosette of leaves and holds its flowering for the second year. They make up for that patient start by self-seeding hard, so once you have a stand going it tends to keep itself going, and any early stumble is easy to recover from.
The one habit worth learning is how to manage rust, a leaf fungus that follows hollyhocks almost everywhere. Give the plants full sun, a little room for air to move, and water at the roots instead of over the top, and you will keep the worst of it in check while the flowers get on with the show.
Care
The short version: give hollyhocks full sun and rich, well-drained soil, keep them evenly moist by watering at the base, and leave a little space between them so air can move and rust stays down.
Light
Give hollyhocks full sun and they will flower their best and stand tall without flopping over. They will accept a bit of partial shade, but where light is too thin the stalks stretch, lean, and bloom only sparsely.
Water
Aim for average, even moisture rather than letting the soil lurch from soaked to bone dry. Water down at the base with a soaker hose or drip line to keep the leaves dry, which is one of the kindest things you can do to slow rust. They will not put up with wet, soggy soil over winter.
Soil
Plant them in average, rich, well-drained loam with a little compost mixed in. They are easygoing about pH and settle in anywhere from 6.0 to 8.0, so sharp drainage matters far more than hitting an exact number.
Humidity
Ordinary outdoor humidity suits them just fine, so there is no target to chase. What really counts is airflow, because still, damp air around crowded leaves is exactly the setting rust loves.
Feeding
One feed in spring is all they ask. Work in compost or a balanced general-purpose fertilizer as growth begins, and the plants will carry themselves comfortably through the rest of the season.
Pruning
Snip the spent flower spikes to neaten things up or to rein in self-seeding if it is wandering more than you like. Just as helpful, strip off and destroy any rust-spotted lower leaves and clear away all the old debris in fall so the fungus has nowhere to overwinter.
Size & spacing
These are tall plants, reaching 5 to 8 feet (152 to 244 cm) high while staying slim at 12 to 24 inches (30 to 61 cm) across. Give each one that full stretch of room so air can move freely between them and rust finds it harder to spread.
When to plant
Hollyhocks run on a gentle two-year clock, so there is no rush. Sow the seed in late summer or start it indoors in late winter, set the young plants out after the last spring frost, and the flowers arrive from June through August of the following year.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter to early spring, about 8 to 10 weeks before the last frost.
- Plant: After the last spring frost once soil has warmed.
- Harvest: June through August.
Hardiness
USDA hardiness zones: 3–9
Temperature: down to -40°C
Troubleshooting
Nearly every hollyhock hiccup turns up on the leaves, and rust is the one you will likely meet first. Find what you see in the list below, then step in early, since most of these are far easier to head off than to chase once they take hold.
Orange freckles above, rusty bumps below
If you spot yellow-orange freckles on top of a leaf with raised rusty bumps sitting right underneath, that is hollyhock rust, and nearly every grower meets it sooner or later. Badly marked leaves turn holey and shrivel, but it is very manageable once you know the moves. Gently pick off the spotted leaves as soon as you notice them, water low at the base so the foliage stays dry, and tidy away every fallen scrap in fall so the spores have nowhere to hide.
Fix:
- Remove and destroy symptomatic leaves early
- Clear all hollyhock debris in fall
- Water at the base to keep foliage dry
- Remove weedy mallows nearby
- Apply a labeled fungicide before symptoms appear if rust is recurrent
Foliage nibbled to a lacy skeleton
When leaves turn lacy, two nibblers are usually to blame, and both are easy to handle. Japanese beetles gather in daylight and leave the veins behind like fine lace, while slugs slip in after dark and leave a telltale slime trail. Try not to worry: pluck the beetles into a cup of soapy water first thing in the morning, and set out baits or traps wherever the slugs are busy.
Fix:
- Hand-pick beetles into soapy water in early morning
- Reduce nearby turf grub habitat
- Use slug baits or traps where slugs are present
Fewer flowers and pinholes in the buds
Fewer blooms than you hoped for usually points to the hollyhock weevil, a small black insect with tan legs and a long snout that likes to perch on the buds and open flowers. It drills into buds and seeds, which quietly thins the show. The kind fix is simple: tap the weevils onto a sheet and get rid of them, then clear off old seed heads where the young ones grow up.
Fix:
- Hand-pick or shake weevils onto a sheet and destroy them
- Remove and destroy old seed heads where larvae develop
Ragged lower leaves with dark blotches
Leaf spot and anthracnose fungi tend to settle into the bottom leaves when a plant stands crowded, stressed, or wet from watering over the top, though happily the flowers stay clean. It can look rough, yet it rarely does any lasting harm. Ease your mind and just pull the worst leaves, open up a little more space so air moves, and water down at the base.
Fix:
- Remove affected leaves
- Improve air circulation
- Water at the base rather than overhead
Toxicity
Here is the reassuring part for homes with pets: the ASPCA lists hollyhock as non-toxic to cats, dogs, and horses, and the flowers are safe enough that people eat them. The only thing to keep an eye on is the bristly leaves and fibers, which can leave a mild skin rash on sensitive people, so it is worth pulling on gloves before you handle or cut the plants.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Rest easy about the cat: the ASPCA marks hollyhock as non-toxic to cats, so a curious taste will not poison your companion. A cat that overdoes it on any greenery may bring a little back up, but nothing here is dangerous.
Dogs None
Dogs are welcome near it as well. Hollyhock is non-toxic to dogs, and about the worst a leaf-chewing pup might feel is a short, mild tummy upset from the roughage.
Horses None
Horses can graze right beside hollyhocks with nothing to fear, because the plant holds no toxic principles for them.
Rabbits Safe
Rabbits can happily eat the leaves and flowers, since these mallow-family plants carry nothing that would harm them.
Livestock Safe
Cattle, goats, and sheep run no toxic risk from hollyhock if they browse a plant along the pasture or garden edge.
Birds Safe
Backyard birds and poultry are welcome to peck at the foliage and seeds without coming to any harm.
People Safe
People are safe around it too, and the flowers are even edible, lovely as a garnish or steeped into tea. The only thing to keep in mind is the bristly leaves and fibers, which can leave a mild skin rash on sensitive folks, so slipping on gloves before you handle or cut the plants is a kind thing to do for your hands.
Contact with the bristly foliage and plant fibers can cause skin irritation (contact dermatitis) in sensitive people; wear gloves when handling.
Varieties
Most garden hollyhocks are the common Alcea rosea, but a handful stand out for their color or for shrugging off rust. These are the friendly few worth knowing by name.
Nigra
You will love how its deep maroon flowers run so dark they read as nearly black against the green spike.
Russian hollyhock (Alcea rugosa)
This gentle relative offers soft yellow flowers and, best of all, shrugs off hollyhock rust far better than the common kind.
Figleaf hollyhock (Alcea ficifolia)
Its charming fig-shaped leaves give it the name, and it stands up to rust better than Alcea rosea, which makes it a forgiving choice.
How to propagate
Hollyhocks are a joy to grow from seed, and once a stand settles in it mostly sows itself for you.
SeedEasy
Sow in late summer (August to September) for bloom the following year, or start indoors in late winter for transplanting after frost. · Germinates in about 1 to 2 weeks; plants form a rosette the first year and bloom the second year.
Growing hollyhocks from seed is about as forgiving as gardening gets. Scatter seed in late summer, around August to September, for flowers the next year, or start it indoors in late winter and settle the young plants out once frost has passed. The seedlings pop up in 1 to 2 weeks, spend their first year as a low rosette, and bloom in the second. Leave the seed heads where they are and the plants happily reseed themselves, filling out into settled colonies over time.
Myths
Hollyhocks are poisonous and must be kept away from dogs and cats.
You can relax on this one. The ASPCA lists hollyhock as non-toxic to dogs, cats, and horses, so a nibble in the garden is nothing to worry about. The flowers are safe enough that people eat them. The only small catch is those bristly leaves, which can leave a mild rash on sensitive skin, so pull on gloves when you cut the plants.
Hollyhocks are reliable, long-lived perennials.
Most hollyhocks are actually biennials, growing a leafy rosette the first year and saving their flowers for the second before they fade. They feel permanent only because they self-seed so freely that new plants keep filling the same spot, so a stand really can carry on year after year.