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Spinach is generally a relatively fast-growing plant that can be planted and harvested multiple times throughout a season. That said, there are several very simple things you can do to make your spinach grow even faster.
I have written this article to give you an easy overview of the five easiest and most effective things you can do to speed up the growth of your spinach. Let’s get into it.
1. Increase the Amount of Sunlight Your Spinach Gets
You can grow spinach without that much sunlight, but more sunlight generally means faster-growing plants. It is not always that simple, however, so let me teach you how to optimize the amount of sunlight your spinach gets to make it grow as fast as possible.
As a general rule, spinach grows faster the more sunlight it gets. That said, it can become too much, though, and if that happens, the plant will begin to flower, which causes it to almost stop producing new leaves and focus on seed production instead.
The best amount of sunlight if you want your spinach to grow as fast as possible is between 10-14 hours per day. With that much direct sunlight, spinach begins to flower relatively quickly, although you will still get to harvest plenty of leaves.
I usually recommend 6-10 hours of sunlight per day for spinach. It seems to give a good mix of fast growth and a long season. The plants won’t grow as fast as if they get more direct sunlight, but they will grow for longer before they flower and most likely end up yielding more in total.
The least amount of sunlight spinach should get is 4 hours per day, although it will grow very slowly at that level. You can read more about how sunlight affects spinach growth and how much is ideal on this link.
The temperature also has a huge effect on how fast spinach grows, although it is, of course, not easy to control. Higher temperatures mean faster growth, although too high temperatures will cause the plant to flower fast. According to this article from Oregon State University Extension Service, the growth rate doubles for every 18 degrees F increase in temperature (although only applicable for an air temperature range of 40 to 98 degrees).
If you want to know more about when spinach flowers and what to do when it happens, head over to this article.
2. Give Your Spinach More Growing Space to Grow Faster
A very common mistake people make when they grow spinach is not giving the plants enough space. If they don’t have enough space, they will grow much slower than otherwise. Keep reading to learn precisely how much space your spinach needs to grow as fast as possible.
Spacing might not be the first thing you think of when you want your spinach to grow faster, but it actually plays a significant role. More space essentially means more room for the roots, which help the plant obtain more water and nutrients, thereby growing faster.
If you grow spinach in pots, you should make sure they are large enough. I recommend pots that are at least 6 inches wide and deep to be sure your spinach has the room it needs to grow as fast as possible.
The material the pot is made of is also important since it can affect the oxygen level in the soil. In other words, how well the soil “breathes”. If the soil can’t breathe, the roots will not be able to obtain water and nutrients so well, which makes the plant grow slower. I recommend some terra cotta pots like these (link to Amazon).
If you use pots that are too small, your spinach can get rootbound, which essentially means that there is no more room for the roots to grow. If this happens, the plant will grow much slower and eventually stop entirely. Spinach doesn’t have that big of a root system, though, so this usually only happens if you use very small pots.
If you grow your spinach outside in the ground, you should space the plants 2 inches (5 cm) apart in rows that are 12-18 inches (30-45 cm) apart, according to this article from PennState University Extension.
The more space your plants have, the faster they can grow since they won’t get rootbound and don’t have to fight for water and nutrients. The growth rate increases exponentially, so the bigger your spinach gets, the faster it grows. So give your spinach good conditions from the beginning.
3. Fertilize Your Spinach With a Nitrogen-Rich Fertilizer
Proper fertilizing is one of the most effective ways to make your spinach grow faster. Here is what you should know.
Garden fertilizers usually have a so-called NPK-value written on them. This value indicates how much nitrogen (N), phosphorus (P), and Potassium (K) it contains.
Spinach and other leafy greens need a fertilizer that has a high nitrogen content as nitrogen helps them develop their leaves.
According to this article from Texas A&M University AgriLife Extension, you should apply a general gardening fertilizer such as a 10-10-10 at the rate of 2-3 pounds per 100 square feet before planting the seeds and again 30 days after the plants come up.
If you can find a fertilizer with a higher nitrogen content, such as 15-10-10, that will also work very well.
You can use a soil test kit to test your soil and see how much nitrogen it has. These kits can be found in most garden centers and many online stores.
4. Water Frequently in Small Doses to Keep the Soil Moist
Spinach contains a very high amount of water, so naturally, proper watering is crucial. I have a few very simple tips you should keep in mind when you water your spinach to give it the best conditions for growing fast.
Spinach grows best in soil that is moist. The soil should never be dry or soaking wet as that will damage the plant.
The easiest way I have found to keep the soil sufficiently moist without giving it too much water is to keep an eye on the top of the soil. When it begins to dry up, you can give it some more water.
In my experience, one small watering per day for each plant is usually sufficient, but growing conditions are different everywhere, so it doesn’t make sense to tell you how often you should water since that would most likely lead to problems. Instead, follow the rule of thumb from above and keep an eye on the top of the soil.
If you give your spinach too much or too little water, the growth rate will decrease, so keeping the soil moist is the best way to make your spinach grow faster when it comes to watering.
The best time to water your spinach is early in the morning, before the sunlight gets too intense. If you water your plants when there is direct sunlight, some of the water will most likely evaporate before it sinks into the ground. That said, if your spinach looks like it needs water, give it some water right away. Don’t wait until the morning.
You can read some more tips for watering spinach as well as how to optimize some of the other growing conditions in this article. Giving your plants proper growing conditions is the key to successful and fast-growing spinach.
5. Grow Spinach Indoors and Outside to See What Works Best
Spinach can grow very well both indoors and outside. It usually grows faster outside, but there are some exceptions where it makes more sense to grow it indoors next to a sunny window or similar. Here is what you should know.
As a general rule, spinach grows faster outside than indoors since it can get more direct sunlight. That said, you don’t want your spinach to get too much sunlight as that will make it flower and stop growing faster.
As I have written earlier in this article, the growing conditions are different everywhere, so I can’t say that spinach grows faster and better outside no matter where you live. This is mostly because it can get so much sun or high temperatures that it will start flowering very rapidly, so while it will grow fast at first, it will also stop fast.
If you have the option to grow spinach both indoors and outside, I highly recommend trying both to see what works best for you and where it grows faster. It will most likely be outside, but you might find out that it grows better inside. I have an article where I discuss growing spinach indoors compared to outside in more detail here.
When I say indoors, I don’t mean anywhere because spinach does need a certain amount of sunlight. See if you can find a spot where it can get about 10 hours of direct sunlight per day for fast-growing plants that don’t flower too fast. Next to a warm, sunny window will usually be good.
If you decide to grow your spinach outside, you might run into problems such as birds and other animals eating your plants. I have written another article where I present a couple of very simple and cheap solutions for this problem.
Now that you know how to make your spinach grow faster, I recommend that you head over to this article, where I share some tips that can help you get as much as possible out of the plants. In the article, I share harvesting tips and other things that can significantly increase the overall yield of your spinach.