Watering is an essential part of growing vegetables and often feels like a mystery when you just get started. There are a lot of different watering methods, things to keep in mind and helpful tricks when it comes to watering, so let’s dive into each of these topics and unveil the secrets of watering together.
How often do I need to water my garden? It’s best to water your plants in the morning, giving them about 0.6 gallons (2.3l) of water per square feet (0.1m). Water your garden 1-3 times a week depending on how dry the soil feels (stick your finger till the knuckle into the soil). Raised Beds and Containers tend to need more water than normal growing beds.
With the quick answer out of the way, let’s start at the beginning with the most important question. That is, why is watering so important? Even plants in the wild survive just fine without it.
Why is Watering so important
Well, otherwise plants will die. That’s pretty obvious so far, so what do plants need water for? The summarized, simple answer is to transport nutrients and energy through the plant and keep its cells expanded. If a plant lacks water, drooping is inevitable, indicating too little water to support its own weight. Similarly, plant growth will be halted if water is lacking.
So why do wild plants don’t need watering? The water household of a plant is dependent on a lot of factors like soil, their root system, evaporation and more. Plants in the wild -for example in a forest- normally grow in moisture-retaining soil, that is shaded from trees, evaporation rates are relatively low and the soil can stay damp for weeks without rain. Plants also did adapt over time to be suited for the environment they grow in, native plant species can survive because they have grown here for a long time.
Lastly, another often overlook the difference between garden and wild plants is their importance of survival to us. If a plant in the wild dies, you’ll probably not even notice but that’s a different story if one in your garden decides it had enough. It’s also a similar story with the yield of the plant, in the wild you just get a nice bonus, no matter how much the plant carries. But if your tomato only produces one single red fruit, I am sure you won’t be as happy. These are just a few reasons, why you need to water a garden, but wild plants are fine without.
When to Water
Knowing when to water your plants can help you to minimize evaporation, reduce disease rate for your plants and overall help them to deal with growing and dealing with the weather conditions.
It’s no secret that watering in the morning is best. First, it’s much easier to water plants in the cool morning and not in the scorching heat. Secondly, water will need some time to penetrate the deep layers of the soil, which can be hindered by intense sun, making most of the water evaporate.
Additionally to less water usage, the morning hours will help your plant prepare for a hot afternoon. The alternative is watering in the evening, which also helps to reduce evaporation and is much easier to combine with normal everyday life.
It’s important to know your soil, here is my recent post all about soil-types, if you have soil that doesn’t drain well, standing moisture can cause root-rot. During the night water will not evaporate, so don’t water soil that tends to be waterlogged in the evening. The same goes with the leaves of your plants, wet leaves will be more prone to fungus problems. Either start watering early enough so your leaves can dry until the sun goes down, or avoid watering leaves at all.
How often do I need to Water
The next step is to figure out how often you need to water your plants. What works best for me is to wait until the top soil is dry to touch (I also use mulch in my growing beds), then water it thoroughly. But let’s not get ahead of ourselves here, how often you water depends on multiple factors, let’s go through some of them.
Soil: As mentioned before soil plays an important part in water retention combined with water drainage. Clay soil will hold lot’s of water and stay moist for a long time, but has problems with drainage, as you might have guessed my garden is mostly clay soil. On the other side of the spectrum is sand with amazing drainage but very bad moisture retention, consequential this soil needs to water more often. Adding organic material will make your life easier, improving both drainage and water retention.
Plant Maturity: Newly planted vegetables will have very small roots and limited ability to absorb water from nearby soil, for those reasons these plants need to be water more frequently. You want to train your plants to develop a strong root system, this can be achieved by watering less frequent once the roots are established and want to expand.
Climate: Well obviously your climate is a huge factor in watering. In hot dry, desert-like climates watering will be much more frequent compared to a wet temperate climate. The easiest way to determine how often to water your plants is by taking things into your own hand, literally. Just feel the soil, if it’s still damp you don’t need to water (keep in mind dew is a thing), once it feels dry to touch give go ahead and do your Raindance (or use another less effective watering method)
Indicator Plants: Plants with big leaves (pumpkin, melons) tend to lose water faster, their wilting indicates when to water your garden. While this is a great way to tell when you definitely need to water your garden, the indicator plant might develop a grudge against you. That being said, during very hot days these plants will always wilt a little bit, recovering in the evening, so don’t panic if they decide to let their leaves hang down a bit.
But please only use this is an emergency indicating method if you get caught off guard, these plants really don’t deserve to be put through hell, just to keep some fingers clean.
Plants wilt but the soil is damp to touch: Imagine you see some of your plants wilting but their soil is still moist. Well the good news, you probably don’t have a problem with a lack of water. The bad ones, something really likes the roots of your plant and went for a snack or too much water caused the plant to suffocate.
As a rule of thumb water your plants 1-3 times a week, plants growing in direct sunlight tend to use more water than ones growing in shade. Water deeply to prevent your plants from only producing shallow roots, otherwise, just follow your gut feeling, the plants will do their best to tell you when they need water.
How often do I need to Water which plant
One thing I didn’t mention in the last part is that some plants will suck your garden dry (-at least if they could) and others just take a small sip every now and then. Well, granted this is a bit of an over-exaggeration, but the point still stands some plants will need more water than others and it’s important to know which are which, so you can plant them together.
Vegetables that require little watering: Beets, Brussels Sprouts, Broccoli, Carrots, Onions, Parsnips, Asparagus, Artichokes, Swiss Chard
Vegetables that require normal watering (important during flowering): Tomatoes, Potatoes, Peas, Corn, Beans, Eggplant, Mustard Greens, Chickpeas, Rhubarb
Vegetables that require lots of watering: Squash, Melon, Radishes, Peppers, Lettuce, Cucumbers, Celery, Cauliflower, Cabbage
How much do I need to Water
After we went through the “Whens” of Watering lets now look at the “Hows”. First up, the amount of water needed to make your plants happy.
A general rule of thumb you should water 1-2 inches of water each week, keep in mind waterlogged soil has to be avoided at all cost, so test your garden and water accordingly.
So how much are 1-2 inches of water? It’s easier to discuss the amount of water needed on a defined area, so let’s take square feet as our base watering area. 1 sqft (0.1m²) needs about 0.6 gallons (2.3l) of water, a normal watering can carry 2.6 gallons (10l) and water 4 sqft of plants.
If you water by hose, filling up a 5 gallon bucket and stopping the time it needs will give you the general idea of your water flow rate. Let’s say you fill the bucket in 10 minutes, this gives you a flow-rate of 1/2 gal/min so you need to water about 70 seconds for every sqft. (0.6 gal divided by 0.5 gal/min = 1.2 min). This Flowrate is dependent on multiple factors like water pressure, hose length, and diameter.
Sprinklers and Drip irrigation can be measured placing a container next to your plants, just stop the time and afterward, you’ll know how long your water system will take to provide optimal deep watering.
Difference between watering Pots, Raised Beds and Growing Beds
Depending on how you grow your plants watering requirements will also differ. Pots will take by far the most water, especially clay pots are known for high water consumption, here is a more in-depth comparison between different types of pots. Raised Beds also tend to require more watering than growing veggies directly in the soil. Still, just stick your finger into the soil and if it feels dry, water it.
The different Types of Watering
Next, I want to take some time to go through the most common ways plants are watered.
Sprinklers: are a widely used way to water plants, they are not very effective but do their job relatively fast. The main benefits of Sprinklers are their price and the area they can reach.
Sadly sprinklers are not very efficient and will also drench the leaves of plants, for those reasons they should not be used during the afternoon & evening. They are an alright alternative in the morning.
Drip-irrigation: Drip irrigation is the over-all king of watering efficiency, transporting the water directly to the root of the plants. Drip-irrigation is expensive to install, for that reason I do not think it’s worth the money for a small backyard vegetable garden.
Hand Watering: The most common way to bring water to plants is still by hand, and that’s for a reason. It’s cheap, easy to adjust and enables you to check the health of your plants on the side. As you might have guessed I also water by Hand, mostly relying on collected rainwater.
How to reduce the amount of Water needed
Here, is an article I wrote a while back talking about ways to reduce water usage in a vegetable garden. I will still mention a couple of methods you can use to improve the water-household of your growing beds.
Mulching: A great way to reduce evaporation and increase the water retention of your soil, is by adding a layer of Mulch. Using grass cutting, straw, leaves or other organic materials help to hold water longer, reduce sun exposure of the soil and will suppress the growth of weeds. Mulching is, all in all, a great and easy way to help with watering.
Soil improvement: Sandy soil is known for its bad water retention and needs to be improved before growing any vegetables in it. The best way to improve soil is by adding organic material in form from compost, straw, etc.
Mulch also helps to improve soil, as it will decompose over time. Mulch will also allow earthworms to get into the higher layers of the soil, which they otherwise would avoid.
Make them cuddle: Planting close together will help to reduce evaporation, this is both true in growing beds and for container gardening. Try to place them as close together as possible, but watch out that the plants don’t hinder each other’s growth completely.
Things to avoid when watering and some Tips
Watering too much will also kill plants: Watering your garden too much is similar to watering it too little. Plants will suffocate when their roots are suspended in water. Drowning plants will also wilt, so it’s important to check if this wilting is caused by lack of water, too much water or some pests.
Water after light rain: It’s perfect to water after light rain, as it alone will not add enough water to penetrate the deeper layers. When watering directly after rain you don’t have to use as much water to get very deep into the soil, encouraging deep root development.
Use a rain gauge: A rain gauge will show you how much water exactly came down during the last rain, telling you if you need to water more. These things are quite inexpensive and can also be built from any old container and some basic math understanding.
Clean plants after dry and windy days: Dust can settle on the leaves of your plant, it’s important to clean it off. Too much dust will hinder the plants’ ability to do photosynthesis, risking it to either grow slow or even die.
Don’t water to fast: Avoid causing your erosion when watering. If half of your growing bed decides to go for a ride with the water you put on it then you should consider reducing the water quantity you use.
Don’t mist your garden: Well just don’t do it. This will increase the risk of your plants catching a disease and is very inefficient to water anything, you’re probably better off not watering your plants at all.
Remove old and damaged leaves: Leaves use up water from your plant, this is true for fresh vibrant ones as well as old nearly dead ones. It’s best to remove old, half dead leaves, so the plant can focus on the healthy ones.
Drought tolerant need water too: Drought tolerant plants are pretty though but that doesn’t mean can just put them in an oven and expect some results other than an air-dried plant. It’s important to help them establish after transplanting and give them some water during extremely dry periods.
Is collecting rainwater worth it? Yes, I can’t stress enough how helpful it is to collect rainwater. I can rely on collected water up until the end of summer, saving me quite some money in the process. Water tanks are not that hard to get and relatively inexpensive if bought used. Making or buying a small collector roof to increase the amount of water you can collect from each rain will make the investment worthwhile.
Can you water plants in the middle of the day? Yes, you can, but I would advise against it. The belief that plants will get burned from noon watering, is not true, the water will evaporate long before it will scorch the leaves. The main disadvantage of watering during the hotter periods of the day is the amount of water lost to evaporation. So if you choose to water in the middle of the day, make sure to water more, than you usually would.