Learn how to Determine and Handle Delicate Rot in Lettuce

Some plant illnesses are worse than others. You may fairly simply dispatch powdery mildew if you happen to catch it early.

However others, like delicate rot, haven’t any recognized remedy and infrequently end in a lettuce crop that’s completely inedible.

A horizontal close up of a lettuce leaf with soft rot on the edges of the leaf.
Photograph by Kristine Lofgren.

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Sorry to begin out on a downer, however I’m not going to sugarcoat issues. Delicate rot sucks.

When it assaults, there isn’t an entire lot that may be performed and it would consign your homegrown veggies to the rubbish bin.

Don’t throw your arms up in despair – although I perceive the impulse. There are issues you are able to do to forestall this illness in your backyard.

And also you additionally wish to be certain your crops don’t have one of many different illnesses with similar-looking signs that can be handled.

That’s the place this information may help. Coming proper up, right here’s what we’ll go over:

That salad isn’t going to make itself. Let’s determine what’s happening together with your lettuce!

What Is Delicate Rot? 

Delicate rot is a illness that infects lettuce and plenty of different species. It’s attributable to the micro organism Erwinia persicina, Pectobacterium carotovorum, and P. polaris.

These micro organism dwell in residing and useless plant tissue and soil, and they are often carried on instruments, clothes, containers, water, soil, crops, or by bugs.

A horizontal close up of a lettuce leaf that has water soaked lesions along the edges.
Photograph by Kristine Lofgren.

When temperatures are between 65 and 95°F, the pathogens quickly multiply.

As soon as temperatures climb above 95°F, or in the event that they dip under 35°F, the micro organism cease reproducing altogether.

The pathogens usually infect a plant by wounds created by pest or mechanical harm, however they’ll additionally soak into the stomata, that are the pores of the plant, when carried by water.

In some areas, that is essentially the most harmful illness of business lettuce.

And along with lettuce, these pathogens can infect different veggie patch crops like cabbage, celery, chilis, tomatoes, potatoes, and squash.


Seeds contaminated with delicate rot will fail to germinate, nevertheless it’s unimaginable to inform whether or not this was the trigger with out sending them to your native extension for testing.

At any price, there’s nothing you are able to do at that time besides take preventative measures subsequent time you sow.

Additionally, in case your seeds fail or your seedlings are symptomatic, toss them out. It’s doubtless the entire packet is contaminated.

A horizontal shot of a lettuce plant in a garden with soft rot along the edges of the leaves.
Photograph by Kristine Lofgren.

Delicate rot causes seedlings to fully collapse. For those who look at the younger plant carefully, you may often see intensive rot on the base.

In older crops, this illness causes water-soaked brown spots to kind on the leaves, in addition to rot within the heart of the crown. Because it progresses, this could trigger the plant to die.

The harm often begins on the older, outer leaves and finally makes its option to the middle of the plant.

To make issues worse, you may suppose your greens escaped this dastardly illness, solely to seek out that they begin rotting after you’ve harvested.

Delicate Rot, Lettuce Drop, or Backside Rot?

Lettuce drop is a illness that appears extraordinarily much like delicate rot. It causes brown, rotten decay on the leaves and stems, and may also be accompanied by a fetid scent.

As well as, you may additionally see wilted patches with a cotton-like mould rising on them on the underside of the leaves. It’s this latter symptom that units lettuce drop aside.

Brought on by Sclerotinia minor, signs are usually solely famous on elements of the plant which might be touching the soil.

Backside rot is commonly confused for delicate rot as properly, not as a result of the signs look the identical however as a result of their names are comparable. Backside rot is attributable to Rhizoctonia solani, which lives within the soil and infects quite a few species.

On leaves that make contact with the soil, rusty brown spots kind alongside the decrease midribs. Stems don’t grow to be symptomatic till the whole plant collapses.

Certain that delicate rot is what you’re coping with? Let’s speak about treating it.


This part left deliberately clean.

I child, however there isn’t any efficient therapy as soon as your plant is contaminated with delicate rot. It’s one of many causes this illness is so devastating.

All you are able to do is pull the plant and eliminate it in a sealed rubbish bag to forestall the an infection from spreading.


To begin with, prevention is all about good gardening practices, like solely utilizing sterile potting media and at all times cleansing your pots and instruments earlier than utilizing them.

A horizontal photo of a gardener's hand in a glove digging in rich garden soil with a wooden-handled gardening trowel.

When planting, maintain your lettuce properly spaced to enhance air circulation, and apply straw mulch across the base of the crops to cut back water splashing.

Don’t water on prime of the foliage. Be sure to’re watering on the soil stage.

Subsequent, do your greatest to maintain pests away as they create openings for the pathogens to enter by. You also needs to take care when pulling out weeds to not harm your crop.

When harvesting, be tremendous cautious to not trigger any harm to the foliage. Do your harvesting within the afternoon when the leaves are dry.

After harvest, retailer your greens between 35 and 39°F within the fridge to forestall the micro organism from reproducing if it’s current.

Lastly, selecting resistant cultivars to start with is your greatest guess at prevention.

Resistant Cultivars

There are lots of delicate rot-resistant cultivars and new ones are coming in the marketplace on a regular basis.

A horizontal photo of lettuce plants growing in rows in a garden. The beds are mulched all around with straw.

Search for the frilly, pink, oak leaf ‘Bacchus,’ the tight heads of the Batavia referred to as ‘Minetto,’ the ruffled iceberg ‘Empire,’ or the Bibb-type ‘Sylvesta.’

The iceberg ‘Ithica’ is an alternative choice, developed by Minotti at Cornell College within the Nineteen Sixties in an effort to create a cold-hardy, disease-resistant plant that may tolerate poor soil and drought.

It gained’t bolt in the summertime warmth both. No marvel it nabbed the All-America Choices vegetable class award in 1963.

A square product photo of Ithaca Crisphead lettuce against a black background.


Add it to your backyard by heading to True Leaf Market. They carry packets of seeds in varied sizes.

‘Magenta’ is one other resistant cultivar, and it has stunning, ruffled inexperienced and bronze foliage on a summer time crisp sort.

It’s a preferred cultivar within the Pacific Northwest as a result of it could possibly deal with nonstop rain for weeks and weeks with out succumbing to rot. It’s definitely harder concerning the winter rain within the space than I’m!

A square product photo of Magenta lettuce.


Carry house seeds for planting from Excessive Mowing Natural Seeds in portions starting from 500 to 500 million.

If free leaf is your factor, ‘New Crimson Fireplace’ is fairly sufficient to be a decorative. It has giant, ruffled leaves which might be inexperienced on the base and transition to pink on the tops.

Much less prone to bolt in the summertime than many different cultivars, it resists fungal illnesses in addition to delicate rot.

A square product photo of New Red Fire lettuce against a white background.

‘New Crimson Fireplace’

Go to True Leaf Market to buy a two-gram, one-ounce, four-ounce, or one-pound package deal of seeds.

Banish This Soiled, Rotten Illness

Like I stated, delicate rot isn’t one thing you wish to encounter. For those who’re already coping with it, my honest condolences.

However now you’re hopefully armed with the data to keep away from it sooner or later. I do know that since I began being extra diligent about prevention, I’ve not often encountered this situation.

A horizontal shot of a few leaves of lettuce suffering from soft rot in the palm of a gardener's hand.

For those who’re going through this drawback now, which signs are you seeing? Or perhaps you could have a favourite resistant cultivar that you just’d prefer to share. Both manner, tell us within the feedback part under.

I’m hoping that you just by no means should face this foe once more!

When you’re on the highway to glad, wholesome, leafy greens, you may wish to be taught extra about rising lettuce. Listed here are just a few guides to get you began:

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