If you suddenly notice that your spinach plant’s leaves have become pointy rather than oval, triangular, or rounded, you’d like to know what’s going on. This happens because of a process known as bolting. What does this mean, and should you be concerned?
Spinach leaves start getting pointy or changing shape when the plant begins to bolt. This indicates the plant is overmature and getting ready to produce seeds. Bolting occurs due to dry soil, increasing daylight hours, and warmer temperatures.
This article covers what will happen to your spinach plant during bolting and why this occurs in the first place. I will also talk about how to spot bolting along with which spinach varieties take longer to go through this process.
What Happens When Spinach Bolts?
Bolting refers to when plants start to produce flowering stems instead of growing and increasing their vegetation. Notably, this can be a problem for spinach, as you mainly harvest the leaves for consumption.
When you start growing spinach in your garden, the plant uses all available resources to produce leaves. After some time, depending on various environmental factors and soil conditions, the plant begins to bolt.
In this stage, all the resources go towards ensuring the plant spreads its genes, even if it doesn’t survive. It does so by shifting its priority towards producing a seed stalk. Flowers sprout on this new stem, which will eventually become seeds.
Is It Bad When Your Spinach Bolts?
So if there is only a change in priority, why does it matter if your spinach plant bolts? Here are two reasons highlighting why it is bad for your leafy greens.
- Bolting is a problem because it reduces your plant’s productivity. This means you’ll get lower yields.
- Bolting changes the taste of your spinach. The leaves become bitter, and you won’t enjoy eating them. As a result, you may have to discard your harvest.
You should check out my complete guide if you’re wondering whether you can save bolted spinach plants. It shows you various methods to rescue your flora if it has already reached this stage: Can Bolted Spinach Plants Still Be Saved?
Still, bolting helps collect the seeds of your spinach plants so you can grow them later. Avoid collecting seeds from hybrid spinach varieties, as you won’t get the same yields.
Why Is Your Spinach Bolting?
Appreciating the reasons behind this process can help you to prevent it from occurring when you plant spinach in the next growing season. If you prevent bolting, your plants will produce more leaves, increasing the total yield.
Below are various factors that can cause your spinach to bolt.
Sowing Time
Spinach is a cool weather plant, meaning you only have a short period to sow it in your garden. If you take too long to plant it, the unfavorable growing conditions increase the chances of bolting. Here are a few pointers you’ll find helpful.
- Generally, when it comes to spinach, the best time to sow is early spring or fall. To grow this leafy green during spring, you should plant it at least four weeks before the last frost.
- Seeds can tolerate temperatures between 35°F – 85°F (1.6°C – 29.4°C). However, for best results, you should germinate the seeds when the temperature is around 45°F – 75°F (7.2°C – 24°C).
- Ideally, you don’t want your spinach growing with 14 hours or more of daylight, as this increases the chances of bolting. This usually happens about 6 – 8 weeks after spring.
- Bolting isn’t much of a problem if you plant in the fall season. Usually, the temperature isn’t high enough to induce this process. However, if you wait too long and daylight is less than 10 hours, the plant won’t spend much time producing leaves. Instead, growth will stop as the leafy green prepares for winter.
- Spinach can withstand temperatures as low as 15°F – 20°F (-9.4°C – 1.6°C). Your older spinach plants will tolerate freezing temperatures for longer before it starts to overwinter. This is when your plant stops growing or producing new leaves and waits for winter to end.
- Ensure there is adequate space between each spinach plant. At least 4-6 inches (10.16-15.24 cm) of space will allow your leafy greens to develop appropriately. If the plants are too close, plant growth slows down, and there is a greater chance of bolting.
Soil Conditions
Another common factor that causes bolting is soil conditions. Spinach requires the soil to be moist. Yet, you should avoid overwatering the plant, as it can cause soil crust formation. This condition is where algae, cyanobacteria, lichen, and moss start to grow on the soil due to standing water.
You want to avoid this at all costs, as it allows all the nutrients in your soil to run off when you water it. Also, the soil can still be dry underground. If you’re unsure whether the soil is moist, you can regularly remove a small patch and check it.
There also must be sufficient nitrogen in the soil for dense spinach growth. Lack of resources can result in bolting. However, this depends on the variety you’re growing in your garden. For instance, fresh market spinach has a slower nitrogen intake, unlike freezer spinach. Notably, the best way to know how much fertilizer to use is to do a soil test.
You also need to consider what you’ve grown previously in the same soil. For example, if you planted cole crops like cabbage, cauliflower, broccoli, brussel sprouts, and kale, there should be sufficient nitrogen for spinach. The same also is true if your previous harvest was lettuce.
When sowing spinach during fall, you should avoid using nitrogen fertilizers. This is because if it rains during winter, it can cause nitrates to leach beyond the plant’s root zone. Also, it increases runoff, which is a waste of resources and can also contaminate the environment.
Spinach Variety
The rate at which spinach plants bolt depends on the variety. Generally, variants like Auroch, Bloomsdale, Gazelle, and Hammerhead, bolt quickly, which means you’ll have to pay close attention to them regularly.
The alternative is to plant the following varieties as they are slower bolting.
- Bloomsdale Longstanding
- Corvair
- Indian Summer
- Lizard
- Olympia
- Red Tabby
- Seaside
Average Temperatures
Temperature is a major factor that can cause premature bolting in your spinach plants. While the leafy greens grow between 40°F – 85°F (4.4°C – 29.4°C), optimal conditions are between 60°F – 65°F (15.5°C – 18.3°C) as the flora experiences rapid growth in this range.
Should the temperature go beyond 85°F (29.4°C) as it does during summer, the plant will start to bolt.
Improper Thinning
If you want to ensure your spinach plant continues to produce leaves as long as possible before it starts to bolt, thinning is essential. This promotes new growth in your leafy greens, increasing yields.
Here are some tips about thinning your spinach plant properly.
- Ideally, you should start thinning when the plant is at least 2 inches (5.08 cm) tall. If you allow the flora to grow without thinning, it can result in stunted growth and bolting – two situations you should avoid at all costs.
- Ensure you handle the plant carefully during this period, as the roots are shallow. If you apply too much force, you may accidentally dislodge the plant from the soil.
- If you notice weeds growing next to the spinach, you must remove them immediately. Weeds compete with your leafy greens for resources, impacting their growth and yield. Again, be careful, as you don’t want to damage or pull out the spinach plant while removing weeds.
Final Thoughts
When spinach leaves start to get pointy or change shape and become smaller, this is a sign of bolting. Bolting makes spinach taste bitter while also reducing the yield significantly.
You can avoid bolting by following optimal sowing practices and growing slow-bolting spinach varieties between 40°F – 85°F (4.4°C – 29.4°C). Plant these leafy greens during early spring and fall. If you sow them during fall, your spinach won’t bolt due to the lower temperatures and shorter duration of daylight.
Finally, thin the plants frequently to encourage new growth.
