by Lance Hill | Jun 2, 2026 | How To, Mirliton, Uncategorized
Mirlitons don’t like wet feet. They spent some 26 million years evolving on the mountainsides of Mexico and Central America, where rain races downhill and barely gets a chance to soak into the porous slope soil before it’s gone. Our job as growers is to recreate those fast-draining, mountainside conditions down in the root zone. When we don’t, the vine lets us know — and the first thing it does is turn yellow.
Why a Waterlogged Mirliton Turns Yellow
Yellowing leaves — what botanists call chlorosis — aren’t always cause for alarm. Mirlitons constantly drop old leaves and push out new ones, so a little yellowing is just part of how the vine grows. Yellowing can also be a sign of disease, like powdery mildew or anthracnose. But when it shows up after a stretch of excessive rain, the most likely culprit is waterlogging: so much moisture in the soil that the roots can’t get any oxygen. Scientists call that oxygen starvation hypoxia.
Here’s what’s actually happening, step by step.
When water fills all the air spaces in the soil, the roots can no longer “breathe.” In response, the plant closes its stomata — the tiny pores on the leaf surface that handle gas exchange and keep the leaf from overheating. Meanwhile, down at the roots, the lack of oxygen forces them into an emergency metabolism that causes real damage and shuts down their ability to extract nutrients from the soil.
One of those nutrients is nitrogen — and nitrogen is a key building block of chlorophyll, the green pigment that captures sunlight and feeds the plant. So as the waterlogged roots stop delivering nitrogen, the chlorophyll breaks down, the green fades, and the leaf yellows and begins to die.
It gets worse underground. Waterlogged soil becomes chemically hostile: toxic compounds and acids accumulate around the roots, further crippling their ability to take up the little nutrition available. At this point, the plant is both drowning and starving.
Here’s what you can do. All these treatments are supported by scientific research (citations below)
1. You can do nothing. Most vines will recover from waterlogging on their own once the soil drains. The catch is time: the longer the roots sit in saturated soil, the more the vine weakens. Prolonged waterlogging lowers the plant’s resistance to anthracnose, stunts vine growth, and cuts into your harvest. Doing nothing is a gamble that gets riskier the longer the wet spell lasts.
2. Directly feed the roots oxygen: You can deliver oxygen directly to the suffocating roots with ordinary drugstore hydrogen peroxide (3%). When it hits the wet soil, it breaks down into water and oxygen, briefly re-oxygenating the root zone. Here’s how to use it: Mix the 3% peroxide with water at about 1 part peroxide to 4 parts water, and pour it slowly around the root zone — not on the leaves. Apply at most every 2–3 days, and only when a soil core still comes up saturated. Skip an application the moment the soil sampler core shows the soil is draining and crumbly again, even if “it’s been three days.” You can also look for new growth on the vine. That’s a sign the vine is recovering
3. Directly feed the leaves: Since the roots can’t take up nutrients while they’re drowning, you can deliver nitrogen straight to the plant through its leaves instead, bypassing the impaired root system. Potassium nitrate (13-0-46) is the right tool — you can buy it here. How to use it: Mix 1 teaspoon into a gallon of water and spray the leaves once a week, in the evening, so the solution has time to absorb before the sun hits it. If your vine is badly stressed, start at half a teaspoon per gallon to be safe, and watch for any leaf-tip burn. Important: Avoid all ammonium-based fertilizers while the vine is waterlogged — in oxygen-starved soil, ammonium actually makes things worse. Stick with the nitrate form.
4. Rain Guard it. You should have a rain guard in place before you even plant the mirliton. Only a rain guard can prevent waterlogging.
5. Soil sample it. Get a soil sampler. If you post a photo of the core sample that you pull, that’s the only way we can help you determine if your vine is waterlogged and when it’s safe to water it again.
4. Shade It. A waterlogged vine is already under stress, and its sun-capturing machinery is impaired. Piling hot, full-sun conditions on top of that just adds heat stress to water stress. A temporary shade cloth (around 30–40%) during peak afternoon sun eases that double burden while the vine recovers. Take it down after the rains pass so you don’t trap moisture and invite fungal trouble.
A few cautions: don’t make it stronger than this, since too much peroxide kills the helpful soil microbes along with everything else; test a small area first
Sources
by Lance Hill | May 19, 2026 | How To, Mirliton, Uncategorized
Overview:
As most of you know, I provide free diagnosis and treatment for mirliton plant diseases and problems to this group. I’m also training Tedra Stanley and Michelle Impastato Glore to do the same. I’m not a formally trained plant pathologist, but have learned through over 40 years of growing mirltons and researching scientific studies on plant diseases.
Expertise matters: You don’t go into your doctor’s waiting room and ask other patients, ‘What’s wrong with me?’ You wait until you see the doctor.
Here are the six steps that we follow when diagnosing and treating your mirliton problems, and the underlying theory behind our approach to handling plant problems whenever you post a photo and ask, “What’s wrong with my mirliton?”
- First, we ask questions:
Lots of them. Because each grower is unique, different varieties, different soils, different beds, different weather, and different watering methods (overhead or base). We need this information to accurately diagnose the problem. When you take a child to a doctor with what you think may be measles, you reasonably expect the first question out of the doctor’s mouth will be, “Has your child been around anyone who has measles?” We need this information because, unlike a professional plant pathology laboratory, we don’t examine the fungi on leaves and stems with a microscope, so we must rely on visible photographic signs of the disease and the plant symptoms-in-context (the plant’s response and its full history).
After you answer the questions, we may ask for additional close-up photos of the plant’s leaves and of the affected leaf or stem. Good close-up photos of the leaves are indispensable because we rely on visible signs of the diseases to diagnose them.
After that, we move forward with our approach to remedying the problem and the theory on which it is based, borrowed from medical doctors: a stepped care model.
2. Can You Get a Quick Diagnosis? Maybe:
If you walk into a doctor’s office with a nail in your foot, no questions are necessary. Same with mirlitons; sometimes we can immediately recognize the problem and recommend treatment. But generally, we need to proceed in smaller steps to give you the most accurate diagnosis and effective treatment.
3. Preliminary Diagnoses:
We will offer a tentative diagnosis of the problem — and it may not even be a disease. It may be due to environmental factors — hardening off, transplant shock, chill damage, insects, over-watering, excessive rain, or sun. We will ask you to flag healthy leaves to see if the symptoms are spreading,
4. Eliminate the Possible Causes other Than Disease:
We first try to eliminate all other possible causes before we progress to the more disease-focused ones. Using the stepped care model, we will start with the least complicated remedies, ruling out other causes before progressing to more disease-focused ones. The problem might be insects or soil moisture, so we want to try insecticides, adding shade, or changing soil moisture to see if that remedies the problem. We don’t want to amputate limbs if you just need a bandage. We want to minimize your work and costs. Medical doctors refer to it as “starting with conservative treatment.”
5. Disease Diagnoses and Treatment Plan:
If we go through all these steps and none of them correct the problem, we will go to the final step: identifying the disease and providing a treatment plan. We will recommend the simplest and least expensive fungicide.
Powdery Mildew and Anthracnose:
The two principal diseases that most frequently afflict mirlitonst are powdery mildew and anthracnose.
Powdery mildew has a simple cure. There’s a time-tested, inexpensive fungicide that will eradicate it: potassium bicarbonate. You only have to apply until the symptoms are gone.
Anthracnose is not so easy. There is no inexpensive and proven solution. The fungus that causes the disease has developed resistance to most chemical fungicides. We are currently testing an organic biofungicide — Timorex Act — but we have not yet obtained conclusive results. And it is very expensive because the company that makes it sells it only by the gallon.
The good news is that although most vines will eventually contract anthracnose, almost all will survive the infection without fungicide and will emerge with some acquired resistance to protect them from the disease the next year.
The most effective way to naturally protect the vine is to reduce water stress (over-saturation) and excessive exposure to solar radiation (by using shade cloths in the summer).
6. Final Step: Report Back so We Can do our job better:
The final step is to ask you to report back the results of any of the solutions we suggest, so we can get better at what we do!
by Lance Hill | Apr 28, 2026 | How To, Mirliton, Uncategorized
Michelle Impastato Glore’s 2026 Spring Mirlitons
We’ve made an important discovery that may change how we grow mirlitons in the U.S.A.
I say “we” because it was the observations made by growers in the Mirliton Facebook group that sparked my interest in why spring mirlitons were flowering females long before males–the exact opposite of the fall flowering sequence. And the reason is that one of the best ways to consistently harvest amid radically changing weather patterns is to focus on getting a spring crop. The fall crop is bedeviled by summer anthracnose epidemics, heat waves, heat domes, droughts, and then fall hurricanes and near-miss traumatic winds. The spring is not.
And here’s why.
The reason mirltons tend to produce females (pistillates) first in the spring is cool weather. This tendency for cool weather to produce female blooms earlier has long been observed in other cucurbits such as cucumber, melon, and squash, and we used that insight to extrapolate that mirlitons were doing the same. All mirliton flowers originate at the axil where the buds emerge. They can turn into a male or female flower. While initial flowering is stimulated by daylight length, the sex of the flower depends on cool night temperature and light intensity. All these factors combine to release hormones that determine whether a floral bud becomes a boy (staminate) or a girl (pistillate). That explains how the cool nights, short days, and lower light in the spring generally accelerate the appearance of females first.
That’s good news because it means that spring flowering and fruiting occur long before the summer heatwaves, droughts, the anthracnose epidemic, and fall hurricanes.
The spring may be your best bet for a crop–not your only crop–but your best bet for at least one crop.
So, how can we take advantage of this discovery?
- If you are starting with a sprout, container plant it as soon as possible in the fall in a 3-gallon container so the biological clock starts ticking. We know that when a sprout has been in the soil–any soil–it will flower and fruit within 110-120 days. So if it is transplanted in the first week of March, it will have time to develop a good canopy and flower lots of females during the ideal spring weather. Always overwinter in containers, then plant in the first week of March. (You can run out and tarp it in the event of a frost)
- If you have an established vine, don’t cut it back in the fall. If you cut back your vine at the end of the fall, you are eliminating your chances for a crop during the safest growing season of the next year—the spring. Frost-protect it through the fall and winter so it emerges with a large canopy that can host hundreds of female flowers in spring. That canopy will receive the full benefit of the cool temperatures during January-April that trigger female flowering. Growers who tent and heat their vines will be blessed with a sure-fire spring crop. And if all things go well in the summer, you will also get a fall crop — that’s just a bonus crop.
- Freeze the male pollen. Males tend to arrive late in the spring, long after the females appear, and this can be a temporary problem because there’s no one to pollinate the females. But we know that Mirliton pollen can be frozen and is viable for at least a year. You can collect male pollen the previous fall, freeze it, and then hand-pollinate the females in the spring. We are working out the specifics of freezing pollen, and we will post the instructions separately–but it’s easy.
So Spring Up to Success Through Science!
by Lance Hill | Mar 8, 2026 | How To, Mirliton, Uncategorized
Many people want to grow their own mirliton (chayote) vine but find it difficult to find locally grown mirlitons. Because of their frustration, some people try to grow mirlitons by purchasing and planting one from the produce department in a grocery store, or online from seed stores. There are two reasons why this is not ideal.
First, all mirlitons sold in grocery stores and markets are imported varieties. They are grown and imported only as produce, just like all the other vegetables that you purchase. The USDA tried to grow these varieties a century ago and concluded that high-altitude plants have tremendous difficulty growing in low altitudes. This is because these varieties have adapted to the altitude, pests, diseases, and ultraviolet exposure in their native environment. The patterns of light and temperature influence when and if the variety will flower and fruit. Moreover, an imported variety may not have acquired resistance to diseases or disease pressures that occur in its new environment.
All imported mirlitons will sprout and send up a shoot, but most imported mirlitons will not flower and set fruit. We have received reports of this problem from hundreds of growers over the years, and I had the same disappointing experience when I tried to grow a vine using imported mirlitons.
Second, even if you could grow an imported mirliton, you may introduce new diseases that have devastated mirlitons elsewhere. Local mirliton varieties adapted to U.S. conditions have been grown for over two centuries in Louisiana and California. These were originally brought from low-altitude coastal areas in the Caribbean and Central America. In horticulture, these local varieties are called landraces —cultivars that growers have improved through traditional agricultural methods. The Louisiana heirloom mirliton is the U.S. mirliton landrace that has adapted to the regional climate, diseases, and pests through generations of trial and error. They are a reliable and healthy variety.
But they are vulnerable to new diseases. Many mirliton diseases have not reached the U.S, and some, like the destructive Chayote Mosaic Virus (CMV), are transmitted inside infected mirliton fruit without any sign of infection (seedborne and sapborne diseases). The U.S.D.A. does not screen imported chayote for diseases becuase, rightfully so, they assume that it will be eaten, not planted. If you purchase infected imported mirlitons that carry the disease and then plant them, you may spread the disease to the Louisiana heirloom mirlitons.
There is no cure for CMV and other viral plant diseases, and planting imported, unscreened chayote can potentially destroy all U.S. varieties. That applies to both grocery chayote and chayote of unknown origin sold online. Read about CMV here.
Plant diseases are constantly evolving and afflicting chayote. In Brazil, scientists have discovered two new plant diseases in chayote. One is a new fungus that causes anthracnose disease in mirlitons — another soilborne and sapborne disease that can be spread through imported chayote. Read the article here.
Read the article about the new seedborne fungal pathogens that cause anthracnose discovered in Brazilian chayote herel https://www.mdpi.com/2309-608X/10/12/847
And another has been discovered: Cowpea Mild Mottled Virus (CPMMV). Read about it here.
To summarize: Imported mirlitons may not grow and fruit in the U.S., and if they do, they may have disastrous consequences for U.S. mirlitons landraces.
by Lance Hill | Mar 8, 2026 | How To, Mirliton, Uncategorized
Many people have asked if there is a danger of interbreeding (cross-pollination) if they grow mirlitons with other squash, like Cucuzza and luffa. That’s understandable because the vines look and flower similarly. The short answer is no, mirlitons and other squash species can’t cross-pollinate.
Mirlitons can only pollinate other mirlitons, and other squash can’t pollinate mirlitons.
But here’s an easy way to determine the danger of interbreeding with any combination of plants.
We usually use common names for plants, but the key to knowing whether they can interbreed is the scientific name, called the “binomial name,” which consists of two words: genus and species. It is analogous to your personal name; your last name is your genus (family name), and your first name is specifically who you are in the family (specie).
To determine the possibility of interbreeding, simply Google the common name followed by “binomial.” For example, if you Google “mirliton binomial,” your first result is Sechium edule, the binomial name you are looking for. Then Google “Cucuzza binomial” and it will return Lagenaria siceraria. Now you know the genus and species of both.
Mirliton: The Genus: Sechium. The Specie: edule
Cucuzza: The Genus; Lagenaria. The Specie: siceraria
The two vines are in different genus (genera is the plural), and different genera seldom interbreed.
What if you have two plants in the same genus? Then look at the second name, the species. If they are the same species, they can generally cross-pollinate-that’s how botanists define species- any plants that are capable of interbreeding. There are exceptions, but to be safe, don’t plant them together until you contact a plant expert for advice.
Now, practice the method on another plant:
Find the scientific names (binomial names) for mirliton and cucumber. Compare them. Are they the same genus? If not, then it’s safe to plant them together.
( Special thanks to Dr. Joe Willis of the LSU AgCenter for his indispensable contribution to this article)
by Lance Hill | Feb 15, 2026 | How To, Mirliton, Uncategorized
1. Vineguard double-arched cattle panel trellis. This can be built using two 16′ panels, with the inside panel cut shorter to provide the canopy space between the upper and lower panels.
Vineguard Trellis with tarp as a rain guard.
Here’s an idea. Design an arched trellis structure to protect mirlitons from excessive rain, solar radiation, and cold. I call it a Vineguard. It can be used to shunt rain away from the beds, shield the vine from intense heat, and protect it from frost.
One structure–three purposes.
We invite you to design and test the concept. (post your ideas and results on the Facebook group)
The concept is simple: An arching structure that you mount above the trellis, similar to the shade cloth structure that many of you already use–but sloped. During periods of heavy rainfall, place a tarp or a single sheet of clear 6-mil plastic on top to divert the water away from the bed and prevent waterlogging.
If you use a tarp, don’t use it for more than 2 consecutive days (the vine will eventually need sunlight), but a clear sheet can be left up for several days. Make sure you allow air to circulate through to prevent overheating and discourage plant diseases. In the summertime, replace the rain guard with a shade cloth to protect from the sun. In winter, you cover the entire trellis with a tarp and enclose the vine to prevent frost damage.
The Vineguard can be built several ways. If you are already using an arched cattle panel, arch another one a few feet above it. If you’re using a horizontal cattle panel trellis, install a PVC pipe arch overhead that slopes to direct rainfall away from the bed (see photo). Or you can construct a similar pitched wooden frame with a pitched roof.
The Vineguard will work for both raised-bed and ground plantings, but it works especially well against waterlogging in tall raised beds. That’s because raised beds provide more control over soil moisture. Tall raised beds are less likely to wick moisture from the rest of the rest of the yard when its saturated.
(When you use the clear plastic rain guard, be careful to leave it up no more than two or three consecutive days, and make sure the enclosure is well-ventilated. It can generate additional heat that might harm the vine.)
We will be experimenting with Vineguards this year, and I invite all you Mirliton Wizards out there to create designs that provide the simplest, most effective, and least expensive model.
Special thanks to R. Ranjith at the Nesamony Memorial Christian College for his advice on soil hydrology and managing intense rainfall.
Thanks to Buster Avera for the photo of his shade-cloth arch, which can also serve as a rain guard.
2. Buster Avera’s arched shade cloth structure could also easily double as a rain guard.
3. Corner view of Buster Avera’s arched shade cloth structure.
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