How Much To Water A Vegetable Garden: Complete Guide


I walked by a vegetable garden recently and started to wonder what it takes to care for one. So, I did some reading online to come up with a complete guide for how much to water a vegetable garden.

How much should you water a vegetable garden? Vegetable gardens require an average of 1 to 6 inches of water every week. Some vegetables will require daily watering, while others can get by with only a few times each week.

Vegetable gardens are a great way to gain access to fresh produce right in your own back yard. Contrary to popular belief, it is not as difficult as it may seem to grow a successful garden of vegetables as long as the planning is through and a few essential guidelines are followed closely.

Why Vegetable Gardens Need Water

It is not a foreign concept that almost all living things survive on water and would die without it. Water serves the purpose of hydrating many forms of life as well as providing energy and even food for some species, such as plants.

In fact, plants contain much more water than any other living thing on earth, with a 90 percent water capacity. They also require so much water because of the chemical reactions that happen within them.

The chemicals that are both produced and taken in by the plant must be transformed using water, which is something that will be explained later in this section.

Plants depend on water in order to carry out a process known as photosynthesis. Photosynthesis is a series of actions the plant will complete in order to create food and energy for itself that will ultimately help it grow and retain its health.

When discussing the topic of how much water a vegetable garden needs, it is important to understand why it is that vegetables actually need water to grow. So, let’s take an in-depth look at the main reason why plants survive on water.

Photosynthesis occurs in several steps that fall under two main stages: the light-dependent reactions and the Calvin Cycle.

Just like the name suggests, the light-dependent reactions that a plant will go through must take place in the presence of sunlight. These actions are performed within a part of the plant that is called the thylakoid membrane, which is located inside the chloroplast. The chloroplast is an organ that is mostly found in the green-pigmented leaves of a plant.

The plant will take in the heat and light energy that is given off by the sun and convert it internally. The light energy will be changed into a form of chemical energy instead.

The energy from the sunlight will then travel through two photosystems inside the plant called Photosystem I and Photosystem II. Photosystems are protein complexes within the chloroplast that will work together to perform the internal functions that occur during photosynthesis.

The photosystems will store the light energy from the sun in order to use it to the plant’s advantage. Within the photosystems, there are more protein complexes that help to actually convert the energy, called reaction centers.

Both Photosystems I and II will absorb the sunlight and go through a set of steps in which they generate energy and pass it to one another. During these steps, electrons are released and photons of light are captured by the reaction center located inside of both photosystems.

Photolysis is the part of the process where the water will come into play. This occurs when the water that has been taken in by the plant’s roots is combined with the stored light energy from the sun.

The water is essentially used as a donor that provides selectrons in order for something called oxygenic photosynthesis to occur. This happens when these substances are split into electrons, hydrogen ions, protons, and oxygen.

The newly created hydrogen ions and oxygen will then be passed all the way back to the thylakoid lumen that was mentioned at the beginning of this explanation. After this happens, the oxygen will be released into the air from the plant when the photosynthesis has been successfully completed.

The second and final stage of photosynthesis is also known as the Calvin Cycle. The reactions during this phase will be completed within a smaller piece of the chloroplast called the stroma. In the most simple of terms, the Calvin Cycle is responsible for actually creating the food and energy for the plant to intake and grow from.

The next set of steps that will be explained are carried out for the purpose of turning the previously collected chemicals into glucose, or sugar, to fuel the plant. This occurs when the carbon dioxide molecules are combined with other chemicals that will break each other down and merge together until glucose molecules are created.

These combinations must take place several times in order for the results to produce just one molecule of glucose. The sugar that exists within the plant after photosynthesis is complete will give it enough energy to grow and basically serve as its food.

Plants need glucose just like humans and animals need food to have any kind of energy to live and carry out movements. In the absence of glucose molecules, the plant will begin to slowly die because it will no longer be able to carry out its natural functions.

Without water in the soil, none of the steps of photosynthesis could be completed, since it begins with the intake of moisture through the plant’s roots. Although the plants do not actually consume the water alone and grow from it, it is necessary to fuel the process of plants creating their own energy.

How Much to Water Each Vegetable: A Quick Guide

The amount of water that a vegetable garden needs will depend on what types of vegetables are planted there. Each individual vegetable plant will require a specific combination of sunlight and water in order to grow to its full capacity and produce the best results.

 It is increasingly important for the gardener to follow the care instructions as indicated on the packet of seeds before planting the garden, or else all of their efforts could turn out to be a waste of time.

Depending on the daily amount of sunlight that the plant receives, it could cause the soil to dry up more quickly. As a result, the plant will need more water than it usually would during other seasons with more shade and less heat. This frequently happens for vegetables that are grown in the summer season, because the sun is most present during this time.

One of the most critical steps involved in planning a vegetable garden is deciding on the type of seeds that you will plant in your soil. This should be an informed decision based on the amount of water that each type of vegetable will require. As a general reference, take a look at this guide to help you decide what kind of vegetables are right for you.

Vegetables that need large amounts of water during dry seasons

The types of vegetables that require the largest amounts of water are the ones that grow during the hotter months of the year. These vegetables include cabbage, cauliflower, tomatoes, celery, cucumbers, peppers, squash, radishes, lettuce, and spinach.

All of the vegetables listed above will need approximately 2 full gallons of water every week throughout their growing season. When the sun is out all day and the soil is drying up during the summer, expect to have to water these vegetables more heavily than any other plant in your garden.

Vegetables that need more water in certain growing stages

Some vegetables in the garden will need more water during certain times in which they are developing. One of the most critical stages to look for while planting beans is the point where flowers bloom on the stems and the actual bean pods are beginning to take their full shape. The bean plant will require at least 2 gallons of water during this time in the absence of heavy rainfall.

If you are planting corn, you can expect to give them a minimum of 2 gallons of water each week once you see the tassels forming around the cobs. Pea plants will also require approximately 2 gallons of water while their pods are forming.

The most important growth stage of a tomato plant occurs within the first month in which the seeds have been plotted, as well as the point of growth where the actual tomatoes are beginning to take shape and flowers are blooming.

At this point, the tomatoes will need 1 full gallon at least twice a week, which is even more than they will usually need during dry weather.

Lastly, you will need to water potato plants with 2gallons of water each week as well, when the potatoes begin to grow to the size of walnuts.

Vegetables that require minimal watering

The vegetables that do not need as much water and maintenance include beets, broccoli, Brussels sprouts, carrots, onions, and parsnips.

Most of these vegetables will be able to survive on a minimum of just 1 gallon of water per week, while some require even less. Beets, for example, will only need 2 gallons every two weeks after the initial growing stages have been completed.

Is It Possible To Water a Vegetable Garden Too Much?

While it is true that vegetable gardens depend on adequate amounts of water every day for survival, there are certain limits that apply to how much water your plants should really be receiving.

Even though water is a great thing for plants that help them to create their own energy and remain healthy, it is possible to water a plant too much to where the excess amounts can actually be harmful.

When a plant is over-watered, the roots will not be able to take in all of the additional water all at once. So, when the capacity of water intake has been reached, the soil around the plant will begin to puddle.

If the buildup of water sits around the base of the plant for too long, the roots below the soil can actually begin to rot. The result of rotten roots in a plant would directly be linked to a poorly grown vegetable at the end of the harvesting season.

So, how can you find out if you are watering your plants too much? A good rule of thumb to follow when trying to determine how much water your garden has received is to feel the soil.

The moisture levels of the soil will tell you exactly how much water has been given to the plants. If the soil is moist and sticky, there is plenty of water for the roots of the plant to soak up.

This can be tested by placing a flat hand directly onto the soil and pulling it up. If there is any excess soil stuck to the palm of your hand, there is more than enough moisture for the plant to extract from it.

If the soil does not feel as soft and sticky, on the other hand, your plants will most likely need more water. It is relatively simple to point out a vegetable garden that needs to be watered because the top of the soil will likely have a dry or cracked appearance.

If you place the palm of your hand face down onto the top of the soil and the surface is stiff, you will need to water the vegetables.

The best time to water your vegetable garden will be as early as possible. If plants are watered later in the day or in the evening, it can put the plants more at risk for sickness and disease.

This is due to the fact that excess water travels outside of the plant’s tiny pores in the stem and leaves. Think of a time that you have seen a moist plant with small drops of water on the surface. This is a natural process that will occur in every plant but will usually evaporate with the help of the heat from the sunlight.

So, if the plants are receiving all of their water at night in the absence of the sunlight, the moisture on the stem and leaves will stay there for several hours. If the plants are watered in the morning, on the other hand, these drops of water will dry up and evaporate by the time the sun goes down and the plant is left sitting idle for a long period of time.

One last thing to note when deciding on how often to water your vegetable garden is the effects that the sunlight can have on the outside appearance of your plants throughout the day. Especially during the hot summer months, multiple consecutive hours of direct sunlight can cause plants to appear wilted as if they are not getting enough water.

However, it is very important to know the difference between a plant that needs more water and one that is just naturally reacting to the increased levels of heat. It is actually very normal for a vegetable garden to look slightly droopy throughout the middle of the day because the plants are adapting to the new weather conditions.

Once you have watered your garden during the morning or early afternoon, it is imperative that you do not overwater your vegetables in fear that they are beginning to shrivel.

Of course, you should always monitor the activity of your garden and propose a solution if any problems persist, but the usual result of this scenario is the plants regaining their healthy appearance by the beginning of the next day when it is time to water them again.

The specific criteria listed above for each type of vegetable that could be planted in your vegetable garden will help you determine how often you should be watering them. Most plants will require daily watering, while some of them will only need to be watered a few times weekly.

When in doubt, a smart rule to follow is to water your entire garden up to at least 1 inch every day. Additionally, the watering should take place at the same time every day to avoid overwatering the vegetables.

What Can Happen to a Vegetable Garden That Doesn’t Get Enough Water?

Since all plants, including vegetables, need water to feed themselves, grow, and survive, it is self-explanatory that they will cease to exist in the absence of water. So, what will actually happen within the plant that will cause it to die if it does not get enough water?

Plants are made up of water almost entirely and they have water pressure all throughout their cells as a result. This is referred to by the term “turgor”, which makes up the skeleton of the plant.

During the process of photosynthesis, plants will soak up water and moisture from the soil with its roots all the way through the stem and finally ending inside of the leaves. The water essentially fills out the plant and helps it to hold its shape throughout its lifetime.

To put this concept into more simple terms, think of a regular rubber party balloon. When you purchase the balloon, it does not look anything like the finished product that is displayed on the packaging. It is a deflated piece of rubber that is much looser and smaller than it appears when it is filled with air.

When the balloon is finally blown up with helium, the shape will start to fill out and it will become round and tight. This is very similar to the skeleton of a plant, which will basically fill up with water and be able to stand up and support itself when it is getting all the nutrients it needs.

Now, think about when the balloon has been blown up for several days after the birthday party and it begins to release some of its helium. In the absence of a full amount of air filling up the balloon, it will begin to shrink back down to its deflated state, exactly how it looked before it was inflated with helium.

This can be directly compared to when a plant has gotten enough water and nourishment to grow to its full capacity, but the gardener slowly begins to stop watering it.

If the owner of the balloon does not continue to fill the rubber sleeve with more air, it will eventually shrivel and stop floating, just like how a plant that has not been watered will become wilted and bent.

The Recipe For a Perfect Vegetable Garden

Despite the fact that there are many mistakes that can be made for beginners who decide to start a vegetable garden, there is an equal amount of ways that the same mistakes can be avoided.

Before executing the actual planting of a vegetable garden, the gardener must have a clear vision of what they would like their garden to look like. This includes choosing between a traditional vegetable garden in the ground or using a raised garden bed.

Raised garden beds are beneficial for two main reasons. First of all, they are much easier to take care of for beginners because they do not require too much maintenance and will generally collect fewer weeds and pests among the plants.

Secondly, a raised garden bed is filled up with new bags of clean soil that do not have traces of harmful chemicals that could be found naturally in the ground. When using one of these elevated planters, the gardener can be absolutely sure that no kind of chemical substance will contaminate the vegetables they are growing.

Large percentages of first-time gardeners have reported high success rates with raised garden beds in comparison to a conventional garden that is not confined to a smaller area. Therefore, opting for a raised garden bed will most likely affect the results of your first harvest positively.

Aside from the location of the actual garden plot, itis important to understand what kind of sunlight levels will reach the exact spot on a daily basis. This is vital to the success of your vegetables because each individual plant will require a specified amount of sunlight per day, just like the minimum water levels.

There are different types of sunlight that shine throughout the day, classified as full sun and partial sun, or partial shade. The minimum required sunlight should be indicated on the seed packet that you can purchase at any local hardware or home improvement store.

These instructions should be explicitly followed to avoid a failed vegetable garden. With the correct combination of sunlight and water on a daily basis, you will be more likely to succeed in your attempt to grow a functioning vegetable garden with fresh produce right in your back yard.

To conclude, the presence and frequency of water in a vegetable garden are needed for the plants to be able to produce energy and grow. Without being watered daily, the plants will shrivel up and lose their shape, resulting in poor quality vegetables or a completely inedible product.

Once the need for water is understood, you will be just a few short steps away from a prosperous vegetable garden.

Related Questions

Where is the best place for a vegetable garden?

Aside from making sure your vegetables can adequately catch the minimum amounts of sunlight each day, it is important to be very careful where your garden is actually placed.

Even though some vegetables will thrive in the shade during most parts of the day, a garden should never be placed directly under a tree, or too close to it at all, for that matter.

The reasoning behind this theory is the fact that trees take in so much water and moisture from their roots that they will stretch deeply through the ground that surrounds them. This will become increasingly true the older the tree gets because the roots will be spread even further out from the trunk.

When planting a new vegetable garden next to an old tree that has been in taking all of the water in the area for several years, it will be hard for your new plants to receive all of the water they need.

So, even though you might be able to grow lettuce in the shade that the big tree in your back yard provides daily, it would not be a good idea to start your garden in that exact area where the water and nutrients would be taken from the seeds you plant.

Are there any vegetables that do not require any sunlight?

Some types of vegetables are able to survive most of their lives in the shade. These plants include the green, leafy types of vegetables such as lettuce, spinach, and kale. Additionally, rooted vegetables such as onions and radishes do not need as much direct sunlight as other kinds of plants that might be present in your garden.

Eyerly Family

The Eyerly Family is a family of 8 that loves gardening. Over the past several years we have been applying what we learn about gardening to our own 16x16 raised back yard garden. Our garden is very prolific and we grow a wide variety of vegetables which we love to eat! Click here to learn more about the Eyerly Family.

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