Crown rot: identify, prevent, control

Updated October 2026

Worst in warm, wet weather on heavy or waterlogged soil, from late spring to autumn in most of Australia and through the wet season in Queensland.

Crown rot is a name for several soil borne diseases that rot the crown, the short, thick base of a plant where the roots meet the stems. Water moulds such as Phytophthora and fungi such as Fusarium, Colletotrichum and Macrophomina are the usual causes, and in strawberries several of them produce the same wilting and collapse. Once a crown is rotten the plant rarely recovers, so drainage, clean planting stock and rotation do most of the work.

Phytophthora, Fusarium, Colletotrichum and Macrophomina species

How to identify it

The first thing you usually notice is a plant that wilts on a warm day even though the soil is moist, then recovers overnight, then wilts again a little worse each day.
Leaves yellow, redden or brown from the oldest ones inward, and the plant stops growing while its neighbours keep going.
If you cut a strawberry crown in half lengthways, a healthy one is white to pale cream inside, while a rotting crown shows red brown, dark brown or marbled streaks.
In rhubarb and globe artichoke, the base of the stalks goes soft, brown and often smelly, and the stalks fall over or pull away easily.
In asparagus, spears are thin and few, the ferns yellow early and die back in patches, and dug crowns show brown, rotted roots and reddish brown streaks inside.
Plants that die from crown rot often do so in a line or patch that follows the wettest part of the bed.

What it is often confused with

Root rot

Root rot and crown rot are often caused by the same organisms and usually happen together. If the crown is still firm and white inside but the fine roots are brown and slough off, start with our root rot page.

Fusarium wilt

Fusarium wilt blocks the water conducting tissue and stains it brown, often on one side of the plant first, while the crown itself stays firm. Crown rot makes the base soft and discoloured right through.

Verticillium wilt

Verticillium wilt yellows and wilts leaves, often on one side, in cooler weather, and the crown stays firm. Cut the stem to look for fine brown streaks rather than a soft rot.

When and where it is worst

Crown rot can turn up anywhere, but it is worst in heavy clay or poorly drained soil, in beds that sit wet after summer storms, and in gardens that are watered every day in hot weather. In Queensland and northern NSW, strawberries grown through autumn and winter suffer most during warm, wet spells, and research in Queensland and Western Australia has found Phytophthora, Fusarium, Colletotrichum and Macrophomina all causing crown rot of strawberries.

Phytophthora spreads in moving water and is most active when soil is warm and saturated, so expect losses after heavy rain from November to March. Fusarium and Macrophomina favour hot weather and stressed plants, and they can survive in soil for many years, which is why old asparagus and strawberry beds often fail when they are replanted in the same spot.

Plants it affects

These plants in our library list it as a problem to watch for.

Asparagus Globe Artichoke Rhubarb Strawberry

How to prevent it

Grow strawberries, asparagus, rhubarb and globe artichokes in raised beds or mounds of free draining soil, and never let water pool around the crowns.
Plant crowns at the right depth, with the top of a strawberry crown just at soil level and rhubarb buds just at or above the surface, because buried crowns stay wet and rot.
Buy certified or virus tested strawberry runners and healthy asparagus crowns from a reputable supplier rather than taking runners from an old, tired patch.
Water deeply but less often, in the morning, and keep mulch a hand's width away from the crowns.
Rotate strawberries to a new bed every two or three years, and plant new asparagus and rhubarb beds where those crops have not grown before.
Remove and bin any plant that collapses, along with the soil right around its roots, so the rot does not spread down the row.

Organic control, step by step

Pull out and bin plants with a rotten crown as soon as you find them, because they will not recover and they shed spores into the soil.
Improve drainage before you replant by digging in plenty of compost and building the bed up at least 20 cm above the path.
Add well made compost every season, since soils rich in organic matter support microbes that compete with root rot organisms.
Rest an affected bed from strawberries, asparagus and rhubarb for several years, and grow unrelated crops such as brassicas, onions or a green manure there instead.
Solarise a small affected bed over the hottest weeks of summer by watering it well and covering it with clear plastic for six to eight weeks, which reduces the fungi in the top layer of soil.

Conventional control

There are no fungicides registered for home gardeners that will cure crown rot in strawberries, asparagus, rhubarb or globe artichokes once a plant is infected, so the focus is on drainage and hygiene.
Home garden products containing phosphorous acid or potassium phosphonate are registered against Phytophthora root rot on some fruit trees and ornamentals, but check whether your crop is on the label before using one on a vegetable or strawberry bed.
Always read the label, check that your crop is listed, and keep to the withholding period before you harvest.

Frequently asked questions

Can I save a strawberry plant with crown rot?

Usually not. Once the inside of the crown is brown the plant has lost its connection between roots and leaves. Pull it out, bin it, and if you want to keep the variety, take a clean runner from a healthy plant in another bed.

Why did my new asparagus bed fail when the old one did so well?

If you replanted in or near the old bed, the Fusarium that builds up under old asparagus can survive in the soil for many years and attack young crowns. Choose a fresh spot that has not grown asparagus, raise the bed and buy healthy one year old crowns.

Is crown rot the same as root rot?

They are closely related, and the same water moulds and fungi often cause both. Crown rot describes the damage at the base of the plant, while root rot describes the damage to the roots. A plant with either one usually has a drainage problem.