Growing pea plants can be a highly rewarding endeavor – just ask Gregor Mendel. However, that doesn’t mean that it can be free of difficulty.
On the contrary, pea plants have a habit of becoming ill without you having any idea why that might be.
Of course, all plants are subject to illness from time to time, but pea plants in particular have fragile roots, and if they are disturbed, you could spoil the entire plant. What’s more, pea plants need just the right amount of water, nitrogen, and phosphorus.
Despite thousands of years of being a mainstay in culinary traditions throughout Europe, Asia, and the Middle East, pea plants can be quite finicky for such a long-standing crop.
That’s just the beginning. Pea plants also have an annoying habit of turning yellow or brown and dying from the bottom upward. Why does this happen, and what can you do about it?
Pea Plants 101
The three most commonly planted pea plants planted in home gardens are English, snow, and snap peas. Each of these are grown early in the spring, when the soil is cold, and grow as the weather becomes warmer.
That said, all of these pea plants’ peas also have a short lifespan once they become ripe, so you’ll want to harvest them sooner rather than later.
In addition, you need to make sure that your pea plants have lots of sunlight and good drainage. Pea plants can grow in the shade, but they won’t flourish nearly as well as they will when exposed to sun.
All garden plants need a balance of sunlight and shade, but peas skew far more toward needing more of the former than the latter.
What’s more, as mentioned above, pea plants’ roots can be finicky, so it’s essential to ensure that they aren’t too moist – as we’ll see below, this can be “at the root” of many “bottom up” pea plant problems.
For best results, water them once per week. More than that, and you risk drowning them and causing things such as root rot. On the other hand, when you water them, make sure you give them plenty of water, lest they dry out.
That said, when the plants are blooming with pods or are exposed to hot and start to mature, those root systems can run into problems.
One of the most important things to keep in mind when planting pea plants is how to support them. Depending on the type, pea plants can grow between two and three or six and eight feet tall.
These plants grow so tall, so you will want to make sure you keep them elevated, unless you want them drooping and flopping over with unfortunate consequences. You’ll thus want to make use of mesh, netting, trellises, and similar materials to keep them in place.
One positive thing about peas is that they aren’t usually affected by disease. As mentioned, many of the problems that arise with peas instead stem from water and soil issues.
However, they’re an exception well-worth paying attention to because aphid infestations can cause yellowing leaves which, as demonstrated below, can be a telltale sign of a “bottom up” pea plant problem.
When Pea Plants Go Bad
While an aphid infestation is one cause, there are many other reasons why your pea plants’ leaves may be turning yellow and brown.
One unfortunate commonality between these different causes is that cures for problem pea plant areas is to remove them, lest the issue spread. There is little chance for successfully curing them and saving the affected areas.
However, that’s what makes it all the more important to be able to identify the potential causes and warning signs of plants going bad from the bottom up, so you can address the issues before they become too widespread.
The most common cause of this issue is something known as fusarium wilt, which also affects tomato plants. It is a fungal disease that gets into your plants via the root system, hence how and why a pea plant infected with fusarium wilt dies from the bottom up.
This condition causes the plant’s foliage to start to yellow and wilt while stunting its growth.
Even more maddening, these plants can sometimes wilt on just one side during the daytime, leaving your plant looking extremely uneven. Worse than this aesthetic issue, fusarium wilt, left unchecked, can kill the entire plant.
Another fungal disease that can result in your pea plant rotting and dying from the bottom up is, appropriately enough, root rot. This is a classic consequence of improper drainage. As excessive water builds up around and soaks your roots, it begins to rot.
Root rot can linger through the winter into spring and summer, infecting the next generation of your pea plant. Making matters worse, root rot can also cause impacted plants to turn yellow, once again, from the bottom up.
Once again, this is a condition that often requires destroying the affected area of your pea plant.
Downy mildew can at first appear like mold on the underside of your pea plant’s leaves, but left unchecked can start to manifest with yellowing leaves and darkened areas on the seed pods.
Powdery mildew, by contrast, is just what it sounds like, mildew that spreads across your pea plant’s leaves leaving a powdery residue behind. It is most common when the weather starts to get warmer.
Ascochyta blight is an umbrella term for a fungal infection that can result from three different types of fungi. As with downy mildew, it can infect your plant during the winter and manifest anew in spring.
In addition to yellowing and brown areas on the foliage, Ascochyta blight is also identifiable by pea plants prematurely dropping their buds and blackened areas appearing on their stems.
Finally, one other insectoid infestation worth mentioning are Mexican Bean Beetles. These can affect pea plants that are grown in the American Southwest and Mexico, and left unchecked can chow down on leaves, leaving them looking skeletal and barren.
They can also cause dark spots to appear.
What You Can Do About it
Your method for dealing with pea plants going bad from the bottom up will naturally depend on what precisely is causing the issue in the first place.
If you are dealing with aphids or Mexican Bean Beetles, you’ll want to look into organic insecticides that can keep your pea plants safe while removing these insectoid invaders.
On the other hand, you may not need to resort to even that, as Mexican Bean Beetles can typically be picked off by hand. The biggest thing to remember here is that you need to be vigilant, since it only takes a few determined aphids or beetles to cause big problems.
However, if you are dealing with a pea plant going bad from the bottom up and especially if you observe yellowing or browning leaves and stems, chances are better you’re dealing with one of the watering, fungi, or mildew issues mentioned above.
For fusarium wilt, you’ll want to remove the destroyed plants and rotate your crops. The latter can help reduce the risk of a buildup of water over the years that can incur such issues.
In addition, there are certain strains of pea seeds that are bred to be more resistant to fusarium wilt, and these are easily identified by an “F” on packages containing them.
Besides getting rid of sections of the pea plant affected by it, the best way to take action against root rot is to make sure you have soil that drains well in the first place.
Buildup of mildew is best treated via crop rotation. This should be done every four years at the least. A buildup of mildew can also be a sign that you aren’t doing a good enough job of keeping your garden debris-free, thus causing detritus to infect plants.
For all of these conditions, you’ll also want to be on the lookout for seeds that are marked as being fungal resistant.
Finally, some methods for treating yellowing leaves include:
- Planting your pea plants in raised soil beds so as to afford it better drainage
- Make use of mulch to protect your pea plant further from rain and other moisture
- Do what you can to stop spores from spreading near them
- Avoid planting pea plants and other legumes in the same place three straight years
- Keep your pea plants spaced adequately apart
No one likes having to deal with yellowing or browning leaves in a pea plant, and a specimen wilting or rotting from the bottom up can be even worse. Link the former to the latter and you may have a full-blown gardening crisis on your hands.
That’s why, no matter which method of treating your pea plant for “bottom up” issues you choose, the single most important thing you can do is act fast. The longer you wait, the worse it will get.
However, if you act in time, you can yet save your pea plants and ensure they flourish for many seasons to come.
Growing up with a mom who filled her home (inside and out) with all sorts of plants, Lisa got her start in gardening at a young age. Living now on her own with a home and yard full of plants (including an indoor greenhouse), she shares all the gardening tips she’s gained over the years.