Knowing your local weather patterns is so important for growing a thriving garden! And El Niño is a persistent and pervasive cycle that has gained attention in recent years. Whether or not it’s an El Niño year can tell you a lot about precipitation, seasonal changes, and temperatures.
I have to admit, living in Houston should have given me an in-depth understanding of El Niño (meaning “little boy” in Spanish), but I didn’t get it until I got into gardening in North Texas. Here the seasons are much more defined than those in the temperate Gulf Coast. Still, this is a focus of my practice in gardening in recent years.
El Niño has a marked effect on gardens outside the regions that feel its more immediate effects. That’s why we’re here today: to discuss how this will affect your garden and how you can deal with it in the coming years to keep your plants happy.
What Is El Niño?
Put simply, El Niño is a weather cycle that originates in two air patterns that flow through North America. These winds – the Polar and Pacific jet streams to be exact – move westward along the Equator in normal conditions and regulate seasonal activity.
In a normal year, these winds move the warmer water of the Pacific Ocean from South America toward Asia. As a result, colder water wells up and moves toward the sea surface as the warm water moves west.
As of late, however, cycles of El Niño and La Niña years have disrupted the normal cycle. What results is a 9-month to (sometimes) years-long cycle of unseasonable weather patterns. These are identified through weakened trade winds, which means warmer waters remain or get pushed toward the east, affecting the Pacific coast.
El Niño Characteristics
Because this warm water is forced further south than normal, you can expect significant changes that vary depending on where you live. In the northern parts of North America, there are warmer and dryer conditions in El Niño cycles. These conditions greatly increase the likelihood of wildfires, drought, and crop failure.
In the southeast and Gulf Coast areas, the weather is wetter, and flooding is more likely. Because upwelling is disrupted in an El Niño cycle, marine wildlife that is normally riding the colder waves are not present in the times they would otherwise be. That means the occurrence of tropical species is more common at this time.
Southwestern US residents are familiar with the very wet winters that El Niño brings. People in typically very dry environments like southern California are often seeing heavy rain with few gaps to allow the ground to dry out. In wildfire-impacted regions, this can cause flooding and mudslides, but even in unburned areas, the risk of flash floods is increased.
After an El Niño cycle begins, the subsequent winter is usually unstable, with dryer winter weather up north and unusually wet winter weather in the south. Maximum cold temperatures reach extremes.
Polar vortexes can be present in the middle to southern parts of the US. People in the central and northeast US will deal with snap freezes. Those in the south will deal with bouts of winter precipitation.
Understanding La Niña
La Niña has some differences, with stronger winds. Image Source: NOAA
To some extent, the inverse of El Niño is La Niña. In these periods, winds are much stronger, and push water around more readily. This means the warmer water is pushed further toward Asia, and colder waters up well with more intensity, pushing the jet stream further north.
La Niña years constitute droughts and warmer winter temperatures in the southern and Gulf Coast regions of North America. The northern parts of North America have even colder winters than normal. Hurricanes are usually more severe, and cold-loving marine wildlife are present in the Pacific Ocean at unusual times.
The Polar Vortex in a La Niña year breaks up and scatters across areas in the middle of the continent to the south. Warmer air heads up north to the polar apex, causing warmer-than-usual weather.
Overall, winter temperatures average slightly higher in La Niña. At the same time, small pockets of polar air make their way into southern areas causing intense snap-cold spikes where normally they wouldn’t occur. This can lead to crop failures and infrastructure issues.
How El Niño Affects the Garden
Knowing the projected impacts of El Niño on your region helps manage changing weather in your garden.
When you know what to expect in a projected El Niño cycle, you know how to deal with the shifting weather patterns in your garden. Here’s a snapshot of what to expect based on your region.
Northern North America
Those in the North tend to have dryer weather with warmer temperatures, and natural precipitation is scarce. Unseasonable warmth makes it difficult to grow plants that prefer cooler weather, and the crops that succeed the most are suited to temperate and warm weather.
Dryness brings about all kinds of problems too. Mites love dry weather and soil. Plants have a harder time in dry weather, as the soil doesn’t transport nutrients as easily when there isn’t adequate moisture. Therefore, they’re even more at risk from attacks by pests and diseases.
Dryer weather than usual in winter can lead to plant death, as water is one of the main insulators of soil in cold weather. Without that extra layer of insulation, more sensitive plants require extra protection.
Southern North America
Those closer to the Equator get a hefty dose of warm, wet weather during El Niño. Flooding, storms, and unseasonably cool weather are common markers. While an abundance of precipitation might seem like a good thing, the extremity of the amounts is a problem.
Flooding can displace soil and cause a lot of problems at the plant level. Those plants that enjoy good drainage and don’t need as much water may have issues with root rot. That also means pests that like moisture in the soil, like fungus gnats, slugs, and snails, may congregate at the root level.
Mildews are more common in damp weather, and you can expect to contend with powdery and downy mildew in an El Niño year if you live in the southern area affected by the shifted jet stream. In general, these conditions make fungal diseases more likely. Rust on plants may become a concern, and leaf spot diseases may appear earlier than anticipated.
In cold seasons, those in the south can expect to have more snow and ice than they would in a normal year. Sensitive foliage may freeze or take on cold damage. Soils may freeze if they aren’t adequately protected. Crop failures are also possible not from dryness but from excessive precipitation that freezes the foliage above ground.
What to Expect In a La Niña Cycle
Northern areas in La Niña experience flooding and fungal diseases, while the south faces drought, heat, and pest outbreaks.
Those in the upper parts of North America are likely to experience the opposite effect in a La Niña year. More flooding and rains are expected, leading to higher occurrences of fungal diseases and soil displacement. Rots and other water stress-related ailments are more common.
In the southern regions of North America, drought and higher heat occur. The pests that thrive in these conditions have increased populations, making it more important for you to be diligent in checking your garden for them. Similarly, drought-stricken plants experience water stress.
One other thing that occurs in a La Niña year is a higher incidence of hurricanes. That means high winds, heavy rains, hail, and other damaging conditions can occur quickly and frequently, even though drought conditions may have been the pervasive theme of warmer seasons.
In temperate areas, winter in La Niña means you may have an extended growing season with incidental threats of cold damage. Especially in southern North America, the air may not get as cold as it would in an El Niño year, but those polar pockets do cause unexpected damage.
Managing Your Garden In El Niño
Let’s start this on the right foot! Despite these shifts, your garden is not doomed. There are easy ways to keep those plants happy and healthy, even though extreme weather patterns are present. Some of these simply involve installing implements in your garden that will provide fortification. Others are strategies that allow you to adapt to these cycles.
Before we get into what you can do, remember to check into what your local and national geology institutions say about the cycles. This gives you the basis you need to act appropriately. However, these tools are just great things to do in your garden regardless.
Spread Some Mulch
In northern regions during El Niño, rain may be scarce, so use mulch for moisture retention and nutrient enhancement.
In the northern parts of the continent, water is scarce in an El Niño year. Mulch is your first line of defense. As your plants grow in spring, and finish establishing themselves, put down a 1-3 inch layer of organic mulch. Straw, wood chips, shredded leaves, and bark are perfect choices here. We carry an awesome brand of straw mulch in our shop too!
These break down over time, lock in soil moisture, and provide your plants with lots of naturally-sourced nutrients. They attract beneficial microorganisms and worms that process the soil further, improving its tilth and helping nutrients and moisture move more easily in the soil.
The people in the southern North American continent will also benefit from mulch as it keeps soil in place in heavy rains. This helps the garden remain intact, and the soil will continue to hold its structure. One thing to note here, though, is you won’t water as much due to sometimes excessive natural precipitation.
Drip and soaker hoses provide gradual, deep watering and are beneficial during drier weather.
This is a tool that improves basically every garden as long as they’re installed properly. Drip and soaker hoses water gardens gradually and deeply. They ensure no splashing, reduced soil displacement, and less opportunity to overwhelm plants with too much water during irrigation.
Whether it’s a dry, warm year, or a wet, cooler one, drip irrigation is a good choice. Snake these around your garden to water right at the root level in times of drought and warm weather. Similarly, use them only as needed when it’s wet and cool.
In an El Niño year in the south or a La Niña year in the north, limit extra irrigation that can overwhelm plants. Reduce water by setting your timer to irrigate less frequently, or don’t turn on your drip irrigation system as often. Use a moisture meter to tell you the water content of your soil.
Utilize shade cloth for extreme heat protection if necessary in your region.
This tool is best employed in extreme heat, so apply this to a La Niña cycle if you live in the southern parts of North America. The opposite goes for northerners in El Niño. Shade cloth, when placed properly, provides an extra layer of protection to plants in hot, bright conditions. It’s useful in dry weather too. While it will still be the winter months, and thus the days will be shorter, a timely application of shade cloth can still make a difference on an unexpectedly-hot day!
You’ll find good quality shade cloths at local nurseries and hardware stores. Look for a 30-40% weave, and find a good way to install it. You can purchase kits that have everything you need: the cloth, a frame, and fasteners all in one.
You’ll want to place your shade cloth at least a few inches away from the tops of your plants to prevent singed leaves that may touch the dark surface of the cloth. Raised beds can have shade cloth draped over a hoop structure or a rectangular structure.
If you happen to have a cover on hinges to protect your plants from winter frost, you can remove the frost cover and replace it with shade cloth. This is an easy, modular way to protect plants from sun and dry weather.
Enhance drainage in southern hard soils before El Niño by working in amendments.
For southerners who typically work in harder soil, El Niño will exacerbate drainage issues through excess precipitation. Therefore, amend harder soils ahead of a rainy season to ensure proper drainage is present. You don’t want to go through the entire process of starting seeds only to have your plants’ roots take on damage when the soil can’t drain water away.
When amending harder soils ahead of the growing season, you can use a couple of different materials to provide some extra drainage. Perlite is a great choice. It’s a byproduct of volcanic activity that adds some grit to the soil while helping prevent compaction.
Amend containers and the top 8-12 inches of ground or raised bed with up to ⅓ perlite. Most potting soils already contain drainage materials and may not need extra. But you can add perlite partway through the season if you notice they’re having trouble draining properly.
Agricultural sand is another option. Use this instead of playground sand, which will form a concrete-like consistency when mixed with water. Agricultural sands are much grittier, providing more sediment for water to flow through. Harder soils generally contain many small particles that hold water, and offsetting that with another organic material is smart!
Prepare for colder seasons with frost cloths, which provide extra protection for frost-sensitive plants.
Frost cloths are great in both wet and dry conditions, especially in seasons when winter is expected to be extra cold. Having these on hand ahead of the fall and winter seasons gives you an extra layer of protection from ice on your frost-sensitive plants.
You can extend the season slightly by draping a frost cloth or greenhouse plastic sheet over a frame. The frame could be a small hoop house, a hinged raised bed cover, or even a square framework structure. The goal is to keep the cover away from the tops of plants – just as you would for a shade cover.
Cover or remove from over the plants as needed throughout the season. If frost cloth is not something you can purchase, an old sheet will do the trick. Remove these when the outside ambient temperature reaches 50°F (10°C) to prevent overheating your plants.
Greenhouses and Cold Frames
Opt for greenhouses or cold frames for robust protection with built-in structures able to endure snow and hail.
Even better than covers are greenhouses and cold frames. These do the same thing frost covers do but come with their own built-in structure. This allows you to cover your plants with a little more fortitude. The hard case of a cold frame holds up more easily to heavy snow, ice, and potential hail than a hoop house would.
If a cold frame isn’t large enough for you, many affordable and professional greenhouse models on the market come in various sizes. Small standalone shelf houses that take up just a couple of square feet are available. These fit easily on a patio or porch.
There are larger, more permanent glass houses too. Small 8×10 foot greenhouses are a common addition in many home gardens. Greenhouses can be standalone or lean against the side of the home. This helps you further regulate the temperature inside.
What’s great about greenhouses, and what many people don’t know about them, is they are useful in cold and warm temperatures. If you climate control them correctly with vents, fans, and heaters, you can have plants in them no matter the season.
Of course, a pro model will be easier to adapt to multiple seasons as opposed to something smaller.
Protection from Winds
Prepare for hurricane-related high winds by grouping flower seeds, staking tall plants, and creating windbreaks.
In years with more hurricanes, high winds are a major concern. You can prepare for this by planting your flower seeds in clusters, staking taller plants, and planting windbreaks for more sensitive plants.
If you have the space, plant a row of hedges on the less sunny side of your garden to fortify others against high wind. Hedges can include taller shrubs, sunflowers, and even dense plantings of hollyhocks. Squash trellises can line this side of the garden too.
This sends the wind high over the hedge or trellis and over the tender plants protected by the windbreak. The winds then move diagonally toward the ground or to the next windbreak, should there be another present.
Placing larger, sturdier equipment in front of your veggie garden or even stone structures will dampen the wind’s strength. The same goes for trees. Strategically planting a line of trees on the wind-dominant side of the garden reduces wind damage to plants behind them and offers a little privacy screen.
Redirect Excess Rainwater
Protect plants from excess rain by redirecting water away from garden beds.
People in regions where rain is prevalent should protect plants from excess moisture by finding a way to redirect rainwater to areas outside of the garden bed. A hoop house frame covered with plastic pushes most of the rainwater to either side of the bed, keeping the plants drier and thus less at risk of developing plant diseases.
Raised beds benefit from hoop houses, and not just as protection from frost. When installed on the bed exterior, they can move the water completely outside the bed. However, you’ll still need to ensure you water your plants enough. You can do this by watering the bed or removing the cover during a rainstorm and replacing it as needed.
Another really cool way to redirect rainwater is to dig small trenches or swales on inclines in between in-ground beds, which redirect the water down into the trench. Line the trenches with rocks to keep the soil in place and make them visually appealing. You can plant water-loving plants at the end of your ditches to add even more interest and color to the garden.
Water catchment is also a potential option for those with space, especially if there is a municipal allowance or program that supports them. Use your roof’s gutters and downspouts to gather the water in barrels to use in the garden at a later time.
Gardening with La Niña
You can use these tools regardless of if it’s an El Niño or La Niña year. Remember the forecasted cycle and choose appropriate tools.
You can use each of these tools regardless of whether or not you’re in an El Niño or La Niña year. The best thing to do is to remember what kind of cycle is in the forecast and determine which tools are best for the season at hand.
Plant protection is key, as we’ve discussed. So is fortification. Some areas will be markedly dryer, and gardeners must focus on irrigation strategies. Those that expect higher winds should employ windbreaks, and so on.
It’s helpful to think of La Niña as the opposite effect of El Niño, but only to some extent. Winters will be slightly different in either cycle in terms of shifting jet streams but could look very similar in their impact.
It’s not hard to set yourself up ahead of the season, ready to contend with all the factors that might suppress healthy plants. Keep your ear to the ground when it comes to these weather patterns, and you’ll find you have a thriving garden regardless of the circumstances!
If you end up dealing with the issue during the season in question, know that you can handle it. Even though weather patterns shift, your devotion to the garden and the plants therein can remain strong.