How Do Houseplants Know What Season It Is?

Each year your houseplants go through different stages of growth, production, reproduction, and resting. Even though they’re in a controlled environment, they seem to go through these stages around the same time each year. So, do they know what season it is?

Houseplants know what season it is by measuring changes to their indoor environment. Fall and winter provide an environment with less humid air because of home heating systems, and longer nights with less sunlight. More light and humidity during spring and summer stimulate growth in your plants. 

This article will explain how houseplants recognize seasons, how seasons affect them, and the purpose of seasons for houseplants.

Growing Season of Houseplants

Like outdoor plants, your indoor plants will also have preferred growing seasons. If your outside plants flourish during a certain season, your houseplants will also benefit from the same season.

The growing season for houseplants is spring and summer. However, like outdoor plants, indoor plants also sense temperature and lighting changes, which generally result in houseplants growing well during spring and summer while going dormant in winter despite being indoors.

As you can see, these are the two seasons during which you can expect the most plant growth from your inside plants. But, remember, all plants are different, and some houseplants will grow more rapidly than others.

Additionally, if you notice your indoor plants struggling to grow during spring and summer, other issues may be at play. You should watch out for some specific signs if your houseplant’s growth appears stunted during the spring and summer.

Here are some things to keep an eye out for if your houseplants aren’t thriving during the warm seasons:

  • Fungal infection
  • Disease
  • Pests
  • Poor soil quality
  • Humidity levels
  • Soil moisture
  • The amount of sunlight available
  • Over/under fertilization
  • Plant temperature

If you notice any of the above symptoms or unfavorable conditions, it’s essential to investigate and remedy the situation as soon as possible. These conditions can lead to your plant becoming ill and eventually dying. 

Luckily, each one of these symptoms can easily be fixed if spotted and treated early.

Dormancy in Winter

Indoor plants have a slight advantage over outdoor plants since they are better protected from the elements. However, your houseplants still sense and benefit from the changing seasons.

Indoor plants typically don’t grow in winter. Most varieties of houseplants go dormant during the colder months, meaning they grow much more slowly and will require less care. So your dormant plants will generally require less fertilizer and water during the winter.

However, some plants grow a little during the winter, but the growth is more subtle than in warmer months. How your houseplant reacts to the winter months heavily depends on the plant type and how cold your home gets during the winter.

Remember that it’s also crucial to let some houseplants get some period of rest during winter to encourage them to bloom in spring. The lack of this dormant or cold period will likely result in a lack of energy during the following growing season.

How Houseplants Recognize Seasons

Indoor plants are a lovely addition to any home since they are a way to bring a bit of nature into your house. However, you may notice that your houseplant’s growth changes throughout the year. These changes in growth might make you wonder if houseplants actually follow the seasons.

Houseplants do follow the seasons. The plants can sense the changing seasons based on small clues like temperature and the amount of light available daily. For example, indoor plants generally thrive during spring and summer. In contrast, many houseplants’ growth halts during the winter.

As you can see, indoor plants certainly do their best to follow the seasons outdoors. Plants are designed to go through different growth steps throughout the growing season as temperatures change, and houseplants are no different.

Even though seasonal changes indoors are harder to detect, your houseplants can still pick up on those changes. They use context clues like the amount of sunlight present throughout the day and changes in temperature. 

Plants placed near windows will especially pick up on these signs.

Many recent studies have found that plants are much more complex than initially believed. It’s stated plants measure the amount of darkness in a 24-hour period and the temperature to recognize the time of the year. It’s also been found plants have cellular memory to know when to go dormant, when to flower, and when to reproduce. 

So, let’s go over the few ways houseplants recognize the seasons.

The Darkness

Longer nights mean shorter days and less sunlight for your houseplants. The winter solstice is the longest night of the year, and your plants only receive about 8 hours and 45 minutes of sunlight, depending on your location.

Since sunlight is part of what helps them thrive and complete photosynthesis, during these days of prolonged darkness, your houseplants will reach for that sunlight. This phenomenon is known as photoperiodism, which is the response to daylight changes allowing plants to adapt to seasonal changes.

So, don’t forget to continue to move them into the sunlight and rotate your houseplants to keep them happy and healthy on all sides.

Temperature and Air Changes

Outdoor plants experience temperature changes in a more drastic way than your houseplants. Since your houseplants are in a controlled environment, most of them may not experience much of a drop in temperature. The closer your plants are to the windows, the more cold they experience

When it drops into colder temperatures, we use heat indoors to keep warm, and the air tends to be drier with less humidity. Plants notice when their environment changes, even when we don’t.

In conjunction with the increase in darkness, these changes indicate winter is here, and your plants begin to halt production and growth to conserve energy. 

COLDAIR Molecule

Studies and research have been conducted to learn more about the complexity of plants. In recent years, it’s been discovered plants contain a COLDAIR molecule that gives them cellular memory.

When this molecule becomes active after experiencing cold or freezing temperatures for about 20 days, it suppresses plants from producing flowers and signals them to conserve energy for the next season. 

These changes create a genetic domino effect called vernalization when plants experience a long period of cold weather to promote new growth and blooming at the end of dormancy.

When springtime is near, the COLDAIR molecule is deactivated, and other genes become activated, ending the vernalization process and allowing the plant to come out of dormancy to be ready for blooming. Additionally, when COLDAIR creates a cellular memory of winter, it helps plants adapt to climate changes.

While most of your houseplants don’t experience harsh temperatures, some of them must go through a chill to continue producing flowers year after year, such as spring bulbs. 

Why Seasons Matter to Houseplants

Season changes are of great importance to plants, and houseplants are no different. Most plants go through a dormancy, vegetative, and reproduction stage, whether they’re indoor or outdoor plants. While most of your houseplants may not go through full dormancy without the chill effect, they’re still in a resting stage to rejuvenate themselves. 

Fall

Even if your houseplants don’t experience cold temperatures, they can sense changes in their environment as temperatures cool with less humidity and nights are longer with less sunlight available.

In the fall, plants are genetically wired to repress floral production to begin conserving energy for dormancy due to changing their living conditions. Their light source is lessened, and humidity levels are decreasing. Vernalization begins, and a gene called Flowering Locus C (FLC) is triggered to repress the essential genes responsible for producing blooms. 

Since growth and blooming use a substantial amount of energy, and there’s not enough sunlight and moisture in the air for houseplants to produce that energy, they go into their form of dormancy by slowing growth and resting to survive through winter.  

Winter

Plants rejuvenate themselves during this period by rebuilding the proteins for their growth spurt during the beginning of their active season. Houseplants aren’t exposed to colder temperatures, so they may not go into full dormancy and die back as plants do outside.

However, you will notice changes in your plants. 

While in the resting period, they’re focused on preparing for their active seasons. Some houseplants have to go through full dormancy by being chilled. For example, daffodils and other spring bulbs must be chilled in the refrigerator to mimic winter cold in order to produce flowers when being grown indoors.

When winter comes, you’ll notice signs your houseplants may be going into dormancy.

These signs may include:

  • The blooming and reproduction have stopped. 
  • Your plants appear droopy.
  • Your plant’s water uptake has slowed. 
  • Your plant’s growth has slowed or is non-existent.

The root system will continue to grow and thrive, and it’s essential to continue routine care and rotate your plants during dormancy, except fertilizing, because it’s not necessary since growth has either slowed or stopped.

Spring and Summer

Spring and summer are the most active months for most of your houseplants because it’s the growing season. 

The beginning of spring is primetime for plants coming out of dormancy with new growth. When vernalization is complete, plants start vamping up their development and begin to produce blooms.

Your houseplants will experience a similar indication spring is here due to their surrounding environment changing and becoming suitable for new growth and blooming. 

The reason spring is exceptionally good for plant growth is due to:

Though indoor plants may not feel all the benefits of spring while indoors, they still recognize the change and benefit from springtime. The sudden change in temperature and amount of light will result in better growth of your house plants, especially when placed near windows that receive adequate light throughout the day.

Therefore, during spring, you can generally expect the following from your houseplants:

  • Increased plant growth
  • Flowering
  • Shinier leaves
  • Larger leaves

These seasons provide warmer temperatures, more humidity, and sunlight to help your plants flourish, flower, and reproduce. 

This is crucial because your houseplants need increased sunlight exposure and humidity to complete photosynthesis to promote healthy growth and blooms. Since your houseplants sense changes in their environment, they’ll adapt if spring or fall comes later than usual.

These conditions allow your houseplants to thrive with the strength of the sun’s rays filtering through the windows and the amount of sunlight they receive throughout the day. 

The reasons summer is good for plant growth include:

  • Increased daily sunlight 
  • Warm temperatures
  • It stimulates explosive plant growth

Since your plants are indoors, they can significantly benefit from all the perks of summertime without the drawbacks such as heat. Indoor plants still take in the extra light from the long days of summer and enjoy the increase of warmth near their window ledge.

Similar to spring, summer promotes healthy growth in your houseplants. 

Often, indoor plants will do most of their growing during the warm months since there’s plenty of sunlight to convert into energy.

The day of the summer solstice provides about 15 hours of daylight, depending on where you live. After the summer solstice, the days become shorter again. Your plants will begin to experience less sunlight available as the fall and winter seasons approach once again. 

How to Trick Houseplants Into Thinking It’s a Different Season

It’s amazing how plants can sense the time of year and know exactly which growth cycle to complete. However, even though plants are great at knowing what season it is, is it possible to trick them into thinking it’s a different one?

You can trick houseplants into thinking it’s a different season by adjusting temperatures and lighting. However, messing with your indoor plant’s seasonal clock isn’t recommended as each plant has a natural growth rhythm they follow to help them grow and stay healthy.

Although it’s possible to force plants into thinking it’s a different season, it’s best to allow them to follow their natural growth cycles. However, there is nothing wrong with providing them with steady temperatures and lighting indoors. 

Your houseplants will still be able to tell when the seasons change.

Tips for Caring for Houseplants During Season Transitions

When the growing season begins and your houseplants are no longer resting, you’ll want to pick up your growing season routine care. However, there are many things to remember when caring for your houseplants during these seasonal transitions.

Here are some of the essential tips to remember:

  • Spring is the best time to repot your plants to optimize growth and blooms. This provides them with a jumpstart from the fresh, nutrient-rich soil. 
  • Continue to keep up with their water uptake. Your houseplant’s water uptake will become more frequent as growth occurs. 
  • About six weeks after repotting your houseplants, give them a nutrient kick with fertilizer.
  • To keep the amount of nutrients needed to optimize healthy growth and blooms, change your houseplants’ potting soil every three to six months, depending on the type of soil you’re using.
  • As fall and winter approach, you’ll notice that your plants aren’t absorbing the same amount of water as they did during spring and summer. While they’re transitioning into their resting state, continue to check their soil and water when needed. 
  • Remember, less sunlight is available, so your houseplants may begin to grow towards the light, creating bending or leaning. Therefore, keep rotating them throughout winter for even sunlight distribution. 
  • There’s no need to continue fertilizing during winter because there’s no new growth.

How to Keep Houseplants Active During Winter Months

If you want to experience continuous growth year-round from your houseplants, you can “trick” them into staying active during the winter months. To keep them active, you’ll need to create a similar environment they experience during the spring and summer months.

Your houseplants need more light than darkness, so you’ll need to use a grow light with a timer. You can set the timer to provide them with the length of sunlight required for the type of houseplants you have. 

Foliage plants need about 14 to 16 hours of sunlight daily, while flowering plants need about 12 to 16 hours.

Your houseplants also need their air controlled by creating higher humidity levels. Plants naturally absorb moisture in the air with their leaves to send to the roots and allow them to cool themselves.

You can schedule this in a few ways:

  • Group several houseplants together under your grow light. 
  • Use a humidifier.
  • Place wet sponges or a bowl of water close to your plants. 

If your houseplants receive the proper environmental conditions for growing, they will continue to thrive throughout the winter months. 

Conclusion

Plants are genetically wired to adapt to their environment when changes are gradual. When seasons change, their environment changes as well. As they measure the length of darkness and air conditions around them, they sense when to stop producing and conserve energy and when to begin growth and produce blooms.

Houseplants such as spring bulbs require full dormancy with cold temperatures to keep coming back with beautiful, healthy blooms each year. 

Alexander Picot

Alexander Picot is the founder of TheGrowingLeaf.com and its lead content writer. He created the website in 2022 as a resource for horticulture lovers and beginners alike, compiling all the gardening tips he discovered over the years. Alex has a passion for caring for plants, turning backyards into feel-good places, and sharing his knowledge with the rest of the world.

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