You may have been told Swiss chard is an easy plant to grow. If this is the case, watching it grow at a microscopically slow rate may have you wondering what’s going on. Swiss chard does grow slowly, but the slowness can usually be attributed to something pretty easy to fix.
Your Swiss chard may not be growing for one of theses six reasons:
- The soil’s pH is off.
- You planted your Swiss chard plants too close together.
- It’s too hot outside.
- Your plant isn’t getting enough sunlight.
- You aren’t watering enough (or are watering too much).
- The plant’s roots have an infection or infestation.
This list may be overwhelming but don’t worry. I’ll give you some tips on detecting each of these things in your Swiss chard plants and tell you how to fix them. We’ll also go over how to grow the best Swiss chard plants possible.
1. The Soil’s pH Is Off
If you’re new to gardening, you may have the basics down: plants need sunlight and water. While this is true, things are a little more complex than that, especially when we begin talking about plant soil.
Your plant’s soil is its home. It’s also their kitchen. They need water and sunlight to grow, but they need nutrients within the soil to grow tall and strong.
Mainly, plants need nitrogen, phosphorous, and potassium, but they also need the following nutrients with the corresponding benefits:
- Calcium: Root health
- Magnesium: Chlorophyll & photosynthesis
- Sulfur: Energy-processing
- Iron: Chlorophyll formation
- Manganese: Photosynthesis
- Copper: Enzymes
- Zinc: Stems and leaves
- Boron: Growth
- Molybdenum: Nitrogen conversion
Like humans, your plants need all of their vitamins and nutrients to grow big and strong. But what does that have to do with soil pH?
Your soil pH level determines what nutrients can be absorbed by your plants.
It can be high (which means your soil is alkaline) or low (which means your soil is acidic). Most nutrients are available to your plants for consumption at a pH level of 6.5, which is just below the neutral score of 7.
So even if your soil has nitrogen, boron, zinc, and all the essential nutrients, it won’t matter if your soil pH is off. Your plants won’t be able to benefit from them if the roots can’t absorb them.
Swiss chard prefers a level between 6.0 and 6.8. So, if your Swiss chard isn’t growing, it might be a nutrient deficiency or an inadequate pH level.
How to Fix This
To determine if this is the problem, you can do a soil pH test or send a soil sample to a lab. I like to use a soil test kit tool that tells you your soil pH and lets you know if your soil lacks phosphorus, nitrogen, and potassium.
There are dozens of soil pH test kits you can grab from a gardening store or online, but most will only tell you the pH. A moisture meter with extra features might read your soil pH, too.
If your Swiss chard’s soil is below or above the preferred range of 6.0-6.8, you may have a problem. Typically, pH issues are fixed with composting or liming. Sometimes, gardeners also use acidic or alkaline fertilizers.
Increasing pH
Liming is a process where you’d add lime to your soil to make it less acidic. You can get liming fertilizer or material at a garden store or online.
However, the effect is not immediate. That’s why lime is often used to increase the pH before the planting season. For faster effects, choose finely ground lime and work it evenly into the soil.
Decreasing pH
If your soil pH is too high, you can try to add some fertilizers rich in sulfur or aluminum sulfate. These can also be found at your local gardening store.
Alternatively, adding an acidic compost can enrich the soil and lower the pH. Try adding more life to your soil by starting some simple composting methods to have compost ready before the growing season.
2. You Planted Your Swiss Chard Plants Too Close Together
You might have wanted to get as much Swiss chard as possible out of your harvest—meaning you put those babies pretty close together. Unfortunately, this will have done the opposite of what you wanted. A full garden bed of Swiss chard might make your plants grow incredibly slowly!
Typically, you want to put your Swiss chard rows 12 to 18 inches (30-46 cm) apart. This can seem like a huge distance, especially if you have a small garden, but if you’ve seen Swiss chard grow, you know that it grows up and out, so it takes up a lot of space.
If you grow them too closely together, roots will get tangled, they’ll fight for nutrients, and they won’t have room to grow to their full potential.
How to Fix This
Unfortunately, if you’ve grown your Swiss chard too close together, there’s little that can be done. Take note and write it down for next year’s garden plan. You can also pull out a few of your slower-growing, weaker-looking Swiss chard to make room for the ones doing well.
3. It’s Too Hot Outside
Most plants have a window of temperature in which they thrive. For Swiss chard, you’ll want cooler weather for its best growth. You can sow the seeds when soil temperatures remain above 40 F (4 °C), but they’ll only germinate when the soil warms up and remains between 55 and 75 °F (13 and 24 °C).
In the summer, Swiss chard tends to grow slower because of increased temperature. Long heat waves can also stress plants and affect their growth.
This doesn’t mean you can’t grow your Swiss chard in warm weather, just that you should plan it out for the cooler months of summer or expect some slow growth.
How to Fix This
To know if the temperature is your problem, you can use your moisture meter or garden thermometer. Some moisture meters have a soil temperature setting to tell you what kind of heat your plants get.
Outdoors, your plants may be exposed to more or less sun based on their location. Reflective materials like your car if your garden is planted right near the driveway and other factors can change the temperature of your garden. Try to consider this when planning out your chard patches.
Also, air temperatures can be higher than soil temperatures because air heats up more quickly. So if the air temperature is over 80 °F, you can cool the soil by watering your plants. If it’s not yet time to water your Swiss chard, you can install a shade cover over them during the hottest parts of the day.
4. Your Plant Isn’t Getting Enough Sunlight
Swiss chard isn’t too picky about sunlight. Most experts will suggest full sun but admit that partial shade still works fine.
Sun, in particular, is responsible for the photosynthesis your plants partake in to help them get taller and stronger. If your plants aren’t getting any sun, they won’t grow, even if they are still getting water and nutrients.
Your Swiss chard needs four to six hours of direct sunlight, meaning it’s not being filtered by tree canopies or taller plants.
How to Fix This
Like our pH and temperature tests above, sometimes a moisture meter will indicate whether or not your plant is getting enough sunlight. You can also purchase other things to check the sunlight in a particular part of your garden patch.
This one from Luster Leaf called the Luster Leaf Rapitest Suncalc (available on Amazon.com) does specifically sunlight calculation. It will tell you if the patch in your garden is sunny, shaded, or partially shaded.
Again, this is a better thing done at the beginning of the season than at the end. If you’re out of options, you could try to get rid of anything that might be shading your plants, like tree branches or other hanging plants.
5. You Aren’t Watering Enough (Or Are Watering Too Much)
Water is vital for plants to grow but should never be given in excess. Your Swiss chard prefers 1 to 2 inches (2.5-5 cm) of water per week. This means that the soil should be watered enough to hydrate 6-8 inches (15-20 cm) deep.
Go the upper limit if it’s particularly hot in your area or going through a heatwave. A mature Swiss chard plant has a large taproot that can access moisture from deep within the soil on days when you don’t water the plant.
Swiss chards prefer well-draining soil rich in organic matter. This means the soil should retain enough moisture for the roots to absorb and should freely drain the excess.
How to Fix This
Watering problems can be an easy fix if you’re not doing it too often. However, when done in excess, it can lead to waterlogging and root rot, which can often be irreversible. In addition, if there’s an issue with soil drainage or you have hydrophobic soil that’s not letting the water get through to the roots, the problem gets more complicated.
Fixing Overwatering and Relieving Compaction
Observe how quickly the water drains from the soil. You’ll need to figure out if you’re having soil compaction issues rather than watering issues.
If the water pools on the surface and takes a long time to seep through the soil, you may have a problem with compaction. In that case, you can work some sand into the top 3-5 inches (7.6-12.7 cm) of soil to improve drainage. Be careful not to damage the lateral roots extending from the taproot.
On the other hand, if you’re simply watering your plant too frequently, you can reduce the watering frequency. Water your plant deeply and check the soil about five days later. Use a moisture meter, sticking the metal probe 10-12 inches (25-30 cm) deep, and water your plant when it reads dry to moist (3-4).
Fixing Underwatering and Improving Moisture Retention
Your plants and soil should be moist by the evening if you water them first thing in the morning. But if the soil 2 inches (5 cm) deep tests dry using a moisture meter only a day after you watered the plant, it means your soil has poor water-holding capacity.
You can apply 1 inch (2.5 cm) of mulch on the soil surface or work compost into the top 3-5 inches (7.6-12.7 cm) of the soil to help improve moisture retention and regulate the soil temperature.
6. The Plant’s Roots Have an Infection or Infestation
Finally, there are quite a few bugs and illnesses that attack the plant’s roots. On the surface, we may just notice that the plant is growing. But down below, a lot is going on.
There are a few things that may be causing trouble. Sometimes aphids, which aren’t typically dangerous, can eat away at roots and shoots.
Root knot nematodes are also common soil pests that can affect many plants with fleshy roots in your garden as soil temperatures rise above 60 °F (15.6 °C) in late spring or summer.
How to Fix This
You’ll know this is your problem if it’s not just your Swiss chard suffering but everything in a particular gardening bed. You’ll likely see more signs above the surface. You can take a magnifying glass and get down into the garden to see if anything is crawling around.
Aphids are easier to deal with, as you can manually remove them with a strong water stream from your garden hose. Spraying your plant with a neem oil solution in the evening can prevent re-infestation.
On the other hand, root knot nematodes are trickier to deal with. You can prevent them from affecting your plants by applying mulch and maintaining soil temperatures below 65 °F (18 °C).
Alternatively, you can grow resistant crops in the same soil in the fall before growing your Swiss chards in late winter or early spring. Rotating your crops is a natural way to reduce their population and prevent damage caused by nematodes.
You can also grow your chards in raised beds with pest-free soil from reputable sellers. If you want to reuse your old soil, you’ll need to solarize it or pour 158 °F (70 °C) water over the infested soil every 5 days over three weeks to eliminate them.
Summary
Swiss chard is an easy-to-grow plant if you can get past its finickiness. It’ll begin to grow slowly if it’s not getting what it needs. Utilize your toolbox (moisture meter, soil tests, pH tests, etc.) to figure out what’s going on. Be observant of other symptoms to make an informed decision about the cause.
