How to Water Raised Beds
When you create new raised beds in your garden, how you plan to water them is very important. It is a good idea to make water a top priority whenever you create a new growing area. In this article, we will discuss the important topic of how to water raised beds. We’ll talk about how to water-raised beds you have already made in the most efficient and effective way possible. And we will take a look at how to integrate an effective water management plan before you make raised beds in your garden if you have not already done so.
Raised beds can be watered by hand or with a hose. But to conserve fresh water and make your gardening more sustainable, you should set up an irrigation system. Drip irrigation, watering globes, or clay pot irrigation are some options to consider. Wicking beds can also be an interesting option. And you should integrate raised beds into wider water management systems.
When thinking about how to water raised beds, there are a number of different things to consider. You need to think about:
- Where the water will come from.
- How to store water for watering raised beds.
- Water efficiency and how you can conserve water in your garden.
- How much water will be needed.
- The means by which the water will reach the beds.
The Pros and Cons of Watering By Hand
You can simply water by hand with a watering can or hose. This has its pros and cons.
One positive of watering manually is that you can make sure that you direct the water to where it needs to go – perhaps favoring certain thirstier plants rather than providing the same level of supply over the whole bed.
However, using a watering can or hose and watering your raised beds by hand can be time-consuming. During warmer and drier periods, you may need to water very regularly, which can take up a lot of your time. Watering by hand also makes it more difficult for you to take a break from your garden.
It can also be very wasteful to water in this way. You will use far less water if you opt instead for one of the irrigation methods mentioned below.
Remember that to be most effective, water should be delivered to the soil beneath the plants, not to the plants themselves. Plants take the water from the soil or growing medium (along with nutrients) through their roots. So to water wisely, you need to deliver the water as close to the roots as possible.
Tips for Hand Watering
- Think about, and cater to, the needs of specific plants.
- Remember that these will differ according to the environmental conditions. (Water more in summer and much less in winter in temperate zones, for example.
- Be careful where you direct the water – water plants at the base, by their roots, not from above.
- Try not to splash the foliage. Usually, you should try to keep the foliage dry. For certain plants, wet leaves can increase the chances of fungal problems/ diseases. And wet leaves can also cause sunburn during hot weather.
- Water early in the morning if possible, not during the heat of midday or in the hot afternoon sun. In chillier times, avoid watering in the evening, too, since damp conditions going into nighttime can increase the chances of problems occurring.
Irrigation Methods for Raised Beds
If you decide not to hand water, this is, as mentioned above, often the best choice. But which irrigation method should you choose?
You could consider a sprinkler system. But this is definitely not the most water-wise choice. Below, we will talk about three much better irrigation options that will allow you to conserve water in your raised bed.
- Drip irrigation
- Watering Globes
- & Clay Pot Irrigation
The first is a great option for gardens of any size, while the latter two are suitable only for smaller-scale raised bed gardens. After we have discussed those options, we will talk about why you might want to consider a wicking bed instead of a regular raised bed and how a wicking bed might be integrated into a hydroponics or aquaponics system, in which you grow plants in water rather than in soil or organic growing media.
|Climate Type||Water||Best Solution For Watering a Raised Bed|
|Temperate||Often, rainwater is sufficient to provide for a rainwater harvesting system, or a fresh water source is available. Water requirements for growing food are less than in other climate types.||Hand watering with rainwater may not be to onerous where rainfall levels are high. But drip irrigation, watering globes or clay pot irrigation can be useful for lower maintenance gardens. In lower rainfall areas, wicking beds, or hydroponic or aquaponic options should be considered.|
|Arid||Water a significant challenge due to low rainfall. Boreholes can give access to sustainable groundwater,though water conservation measures are required.||Drip irrigation or clay pots are often essential in these low rainfall areas. (And water conservation is even more important. In some cases, hydroponic or aquaponic systems can be the best option.|
|Humid Subtropical/Tropical||Water abundant during the rainy season, can be very scarce during the dry season. Water storage/ conservation is essential.||Watering needs are often minimal in rainy season. But drip irrigation, or hydroponic/ aquaponic solutions should be considered for dry periods.|
Drip irrigation is about the targeted delivery of water to plant roots a little at a time. A system of pipes or perforated hoses will carry the water through the raised bed and let small amounts of water out to keep the growing area moist.
If you have a small garden, there are several small-scale options to choose from. One option is a bucket system. In a bucket system, the bucket is supported on a bucket stand, with the bottom of the bucket at least 1 m above the planting surface of the raised bed. You will water into this bucket, and the water will then be fed from there along with a soaker hose or irrigation pipes with nozzles on them which drip out water slowly below your plants. These might be laid along the surface or hidden below the surface mulch.
You can also connect a drip irrigation system directly to your water supply – either to your mains supply or, ideally, for the reasons mentioned above, your rainwater harvesting system. There are a number of different drip irrigation kits that you can purchase – or you can buy component parts and make your own.
The first step is planning the system. Of course, you need to map out your different growing areas and think about how much (if any) irrigation will be required.
Ideally, each drip tube should serve an area with similar watering needs. Growing plants that like similar growing conditions and have similar water needs in a raised bed can make your life easier.
By carefully thinking about how and where a soaker hose or drip irrigation line runs, you can also have a much higher level of control over how much water is delivered, not just to whole growing areas but to individual species and individual plants.
A variation on this is wicking systems. In wicking systems, small quantities of water are ‘drip fed’ to plants by means of wicks of fabric or matting. The water does not travel along pipes to be dripped near plants but rather passes through a medium by means of capillary action.
Like soaker hose and drip line irrigation systems, this type of irrigation can deliver smaller quantities of water to exactly where it is required.
Soaker hose or drip line irrigation systems can also be fitted with automated controls. So you can tailor the amount of water that is delivered by this system throughout the year. And like overhead irrigation systems, these systems can reduce the effort that must be expended by the gardener. But small scale systems can also be set up and managed manually to give pin-point control over garden watering.
Even if you prefer not to have an automated system and prefer to water manually, or do not want to invest in a full irrigation system, there are still some other irrigation methods to consider that can help you use water more wisely.
One way to make watering a little easier, and to save water, is to make use of watering globes or other receptacles that will release water slowly into the soil over time.
Filling up watering globes or, for example, wine bottles inserted upside down into the soil of beds or containers can remove the tyranny of daily hand-watering and be a great solution if you are short on time or wish to take a break for a holiday.
Water will slowly be drawn down from these globes or bottles into the soil and be taken up by plants nearby.
Clay Pot Irrigation
Another option is ‘clay pot’ irrigation. This traditionally involves sinking an unglazed clay pot into the soil at the base of plants. It is typically implemented in arid climate zones but could also be something to consider in wetter climes.
In these systems, rather than watering on the soil surface of watering plants from above, the gardener pours water directly into the pots, so it is delivered below the surface of the soil. This means that less will be wasted on evaporation, and plant roots will be able to use it all for their needs.
It is traditional to use clay pots, which are permeable and allow the water to leach out into the surrounding soil as required. But a similar result can be achieved by sinking plant pots or other receptacles into the soil near your plants.
What is a Wicking Bed?
A wicking bed involves using a soil/organic matter-based growing medium. But unlike other raised beds, it involves a fully integrated water system rather than requiring irrigation. It comes with its own reservoir of water at the base.
You can make a wicking bed with a reservoir that can simply be topped up by hand with a watering can. Or one that is integrated with a rainwater harvesting system, or even with a hydroponic or aquaponic system in which plants are grown in water.
Water is drawn up through ‘wicking’ or capillary action through the growing medium from the water reservoir in the base of the bed. This provides the plant roots with the water they require, and less is lost to surface evaporation.
This is, perhaps, the ultimate solution when deciding how to water raised beds if they are not already in place. So if your starting fresh, consider this option before you build your beds.
Which is the Best Water to Use for Raised Beds?
It is best to use rainwater and natural water sources like springs on your property where possible. Catching rainwater and managing water flow on your property is essential if you want to make the most of your garden and successfully irrigate your raised beds.
Rainwater is better for garden plants than relying on a treated mains water supply, which may contain chlorine or other substances that may not be ideal for plant health. And even when the water is from your faucets is fresh and pure, it is important to consider where it comes from and the infrastructure required to bring it to your home.
To be as eco-friendly, sustainable, and self-reliant as possible, you should always do what you can to meet your garden needs with water you collect from natural on-site sources.
How To Harvest Rainwater For Your Raised Beds
One important thing to think about, if you have not done so already, is how you can divert water that falls on the roof of your home. Install guttering if this is not already in place on your property, and direct the water so you can store it or use it in your garden.
Remember, you can also collect water from the roofs of other structures on your property, from garages or sheds to greenhouses or growing tunnels.
Storing Rainwater For Use in the Garden
The rainwater that you catch on your property can be stored in a range of different ways. You can:
- Direct it into rainwater butts, barrels, cisterns, tanks, or other containers.
- Direct it into reservoirs or permanent ponds.
- Channel it directly from catchment points into garden beds or growing areas, where it will be stored within the plants and the soil or growing medium.
How To Conserve Water in Raised Bed Growing
Thinking about how we can store water not only within containers and ponds but also in plants and soil is crucial in an organic garden. Understanding how water interacts with plants and the medium in which they grow is very important. It is vital when learning how to water-raised beds to consider water conservation.
Whether you live in an area with abundant rainfall or somewhere where rainfall is scarce, it is important to take steps to use water wisely and to waste as little of it as possible. Freshwater is a precious resource, and we should not squander it.
Conserving Water in the Soil
Your gardening practices will play an important role in determining how much water you need for the plants in your raised beds. One key thing to think about is how you can maximize the amount of water that is captured in the soil/ growing medium in your raised beds.
How well the soil in your garden is able to hold water will, of course, depend on what you have used to fill your raised bed. If you have filled your raised bed with soil from your garden, then it will depend on what soil type you have in your area.
Soils with a lot of clay in them will be much better at retaining water. While sandy, fine, and free-draining soils can be far less effective when it comes to water retention. If you have used other materials to fill your raised beds, the materials you have chosen will determine how moisture-retentive or free-draining the substrate will be. (We’ll discuss some of the materials you can use a little later in this article.)
There are a number of things that you can do to make sure that the raised bed growing medium is able to retain as much water as possible. These things should be considered before you even begin to think about how you will water or irrigate your crops.
To improve your raised bed’s ability to store water and to reduce the amount of water you need to use to water raised beds:
- Make sure you do not leave bare soil. Cover the soil as much as possible.
- Add organic mulches over the top of the raised bed. Organic mulches might include carbon-rich materials like straw, nitrogen-rich leafy mulches, brown organic matter like homemade compost, leaf mold, or well-rotted manure. They might also include living mulches – ground cover plants that surround your main crops in the bed.
- Use cover crops/ green manures to fill any gaps in your planting schedule (over the winter months, for example).
Conserving Water Through Raised Bed Design
How you fill your raised bed is important. There are a number of different ways to make raised beds, and some designs will be better for water conservation than others.
A raised bed with more organic matter in it will tend to store more water than one that is filled with soil.
A lasagna bed is one type of raised bed that can be great for water conservation. In a lasagna bed, you build up the bed to the desired height with organic matter that is allowed to compost in place. You build up layers of carbon-rich and nitrogen-rich organic materials just as you would do in a compost bin. Then top the bed with a thin layer of soil/ compost into which you can sow and plant. You then mulch around the plants to rebuild as the materials decompose and sink down over time.
A similar idea – hugelkultur – can be even better for water conservation. A hugelkultur raised bed is often a mound rather than a flat-topped bed. But the idea can also be customized to make more typical raised beds. At the heart of the mound is a core of rotting woody material, which soaks up water like a sponge. Other organic materials are then added as above around this core structure.
Another important thing to consider is raised bed design is what the bed edging is made from. Materials like metal, for example, or dark-colored plastics heat up quickly in the sun and could make a raised bed dry out more quickly. Wood is a good material to choose from. Though it won’t last forever and will break down over time, it will also absorb and hold water and reduce watering needs.
Conserving Water By Creating Shade
The water in raised beds is stored not just in the soil/ growing medium but in the plants themselves. So another key thing to consider when thinking about water conservation is how you can reduce the amount of water lost from plants -especially during the warmer months.
One key way to reduce moisture loss from both the soil and your plants is by creating shade. You might create shade in your raised beds by erecting shade covers or shade netting. But you can also create shade by making careful plant choices. Taller plants can be chosen and positioned so that they cast shade over another part of the bed during the hottest part of the day.
In the northern hemisphere, this means placing taller plants to provide shade to the south or west of the raised bed. You might also erect a trellis or other support structure and grow climbing plants up it to provide shade for other plants in the bed.
Considering the Water Needs of Different Plants
When learning about how to water raised beds, it is important to think about water conservation. But it is also crucial to understand your plants and their specific needs. Remember, some plants will require a lot more water than others. And the water needs of the plants will change depending on the weather conditions – the amount of sunlight, how much rainwater that naturally receive, and the temperatures.
You can work out which crops to grow in your raised based on their water needs. Here are some common crops and how much water they need in relation to grass.
|30% Less||10% Less||Around the Same||10% More||30% More|
|Citrus trees||Squash/ Pumpkins||Carrots||Grains (e.g: millet, sorghum, maize, flax, oats, wheat)||Paddy rice|
|Olives||Radishes||Beets||Eggplants||Banana (& some other tropic fruit trees)|
|Cabbage family||Potatoes (& sweet potatoes)|
|Spinach (and other similar greens)||Sunflowers|
This can help you work out which plants it might be a good idea to grow in your raised bed, depending on the climate and conditions in your area.
Growing less ‘thirsty’ plants could make it easier for you to water your raised beds if you live in an area where natural rainfall is lower. Plant choices should always be tailored to the conditions where you live and the resources (including water) that are available.
Xeriscaping is the name given to planting that is climate-aware and suitable for more arid areas. Such a scheme in a raised bed may need minimal watering if it needs to be watered at all.
Usually, however, people want to grow common annual/biennial crops, so there will usually be at least some need to water the bed on a regular basis. So you will need to decide how you will take the water from rainwater storage vessels or another supply point and provide it to your plants.