For those of us who love DIY projects, making plant pots – or planters – with the help of concrete mixers is great fun. Making planters with concrete mixers is as simple as operating your mixer and pouring your newly mixed cement into a mold. Next is the choosing of the most appropriate plant for your pot, as well as decoration. Despite the easy nature of the project, there are several important aspects that must be considered during the process. In just a few minutes of reading, find out exactly how to create concrete planters with the use of concrete mixers, as well as pick up some great plant tips along the way.
The nature of plants
It should come as no surprise that plants can be incredibly finicky, and it is easier than we think to overwater or underwater a plant. Should they receive too much, or too little, they can perish. Where some plants can survive only with several hours of direct sunlight, others require indirect sunlight and can become burnt if exposed to the sun’s harsh rays. As if that is not complicated enough, plants have a set preference for the composition of soil they must be planted in, as well as the pH of the soil in question. All things considered, it is actually quite surprising that so many potted plants thrive at all.
Plant lovers who are interested in creating planters with concrete mixers often express concern over whether or not concrete planters are safe for all plants. This is a good concern to have, since concrete can be indeed be harmful to some plant species – mostly because some cement mixes contain lime in them. The presence of lime is what alerts most green thumbs to potential harm to their plants. Even though lime is not toxic, it has a rather high pH level – which means that it is highly alkaline, and there are certain plant species that cannot thrive, or survive, in higher alkaline soil.
The common existence of lime in many cement mixes can be attributed to the fact that most manufacturers of cement and concrete use Portland cement as the base material for their mixes, and Portland cement contains lime. Some manufacturers will proceed to add other compounds and minerals to their mix for a number of reasons, such as to increase strength or shorten curing times. Although it is possible that more plants need acidic soil – you will be relieved to learn that there certainly are plants that thrive on an alkaline environment that will be provided by lime-containing cement mixes.
One example is succulents, which are known to thrive on higher-alkaline environments. Therefore, they are a great plant option to place in your concrete planter. Succulents are not the only plant species that enjoy higher-levels of alkaline. We have compiled a list of some plants that will thrive in concrete pots due to the pH of the soil that they might ensure:
One of the most commonly found vegetables in the household, and the nightmare of many picky children around the world, broccoli is packed full of nutrients that prevent disease, support the immune system as well as maintain a good hormonal balance. Broccoli thrives best in full sunlight, meaning that placing your broccoli-filled concrete planter outdoors is a good place to start. Growing your own vegetables is always a good idea, since you can be sure that no harmful chemicals and insect-repellents have been used.
This diverse and widespread family of flowering plants produces beautiful, colourful and often patterned blooms, ranging from yellows to whites to stunning pinks. These plants thrive on indirect light, and need to be planted shallowly. Planting them in a plain concrete planter will allow their natural beauty to shine without distraction.
Traditionally used to treat sores and muscle aches, oregano was used for centuries as herbal medicine, and still is in some societies today. Oregano should be placed in a sunny yet sheltered spot, in a planter that has a drainage hole. Leaves should be harvested as needed, and every so often the plant should be re-potted with fresh soil.
This perennial flowering plant is native to moist, subtropical climates, though many species are usually grown indoors in planters in cooler climates. These compact and cushion-like plants can grow up to 25cm in length, and boast a variety of different colour variations. Due to their love for high-alkaline soil, they would be a great plant option to thrive in your lime-containing concrete planter, and bring colour and beauty into your home.
Concrete planters can be made safe for other plants
Making a DIY planter using concrete mixers does not have to limit your plant choice to the above examples due to the existence of lime in the cement which promises a higher alkaline in the soil. There are several way to fix this situation. One such solution is to soak the planter in water for three days, which should leach the alkalinity out of the concrete. If you live in a rainy environment, leaving the cement planter outside for a few rainy days will also suffice.
If you want to be extra sure that alkalinity will never pose a problem, you also have the option of sealing the concrete pots, which we will address shortly. Before you decide to seal your concrete pot, you should know about a few important functions that they serve when they have not been sealed. In their raw form, concrete pots are porous, and porous materials can only benefit plants inside since it helps to control overwatering – another reason that concrete planters are excellent pot choices for plants.
Should you seal your concrete planter, it will become non-porous. However, there are advantages to sealing your concrete pots, one being that it will help to reduce efflorescence, which can be described as the white residue that you may see coming through the outside of the concrete pot for which the soil is responsible. This residue can be attributed to the minerals in the soil. In sealing the planter, you could be preserving the longevity of the concrete pot. Concrete sealers can be found in, or ordered from, most hardware stores or warehouses.
What do you need to make concrete planters with concrete mixers?
- Cement, water and aggregate to place in your concrete mixers
- Disposable cup
- Disposable bowl
- Safety glasses
- Safety mask
- Durable gloves
- A straw or small pipe to create the drainage hole
- Hot glue
- Utility knife
- Plastic bottles, buckets and containers
Most cement mixes can be used to make planters, but whether or not your pots will durable and aesthetically pleasing depends entirely on what you choose to use as a mold. Ideally, you will allow the mixed cement to become completely smooth in your concrete mixers before you pour your mold, without any lumps. Once you have cast your planter, you will need to vibrate the wet mix within the mold. If you fail to do so, it is likely that your pot will have pin holes or pock marks (air gap holes).
The importance of drainage holes
If you know anything about growing pot plants, you are likely to have an understanding of the importance of drainage holes. Without them, the possibility of root rot and a dying plant is extremely common – especially for inexperienced plant growers. Even though concrete is a porous material, it is not possible for the substance to absorb enough water to prevent the abovementioned issues. There simply must be a way for water to escape the pot.
While some people prefer to drill a drainage hole in the bottom of the concrete planter after it has dried, others advise to include the feature in the mold itself. The size of the hole depends on the size of the planter. For tiny planters, one ¼ inch should do the trick. For larger, rectangular planters, two or more 7-inch holes should suffice.
You can make drainage holes in the mold using large or small drinking straws. This can be done by cutting a drinking straw to have the same thickness of the base of the pot. After this, proceed to use hot glue to glue it to the bottom of the mold, and filling in the open end of the straw with glue or another sealing material.
Curing concrete planters
The time period in which you cure your concrete pots depends completely on the type of mix you used as well as the size of the pot. Most cement mixes will require about one day to cure, and a following few days more to dry completely. However, larger concrete planter boxes with walls thicker than 2 inches are likely to take much longer than 24 hours. Although some mixes boast “rapid-setting” properties, it is best not to rush the process should you wish to avoid disappointment.
Colouring your concrete planter
Another important consideration in the choice of concrete mix is colour. Some concrete mixers are grey, whereas some are white or even beige. Should you wish to have a colourful concrete planter, consider using white cement so that the colour will show up brighter and purer once added. Arguably the easiest way to colour your concrete planter is to add pigment to the mix before pouring. There are a number of different pigments that can be mixed in with cement, such as specially-created concrete pigments in powder form, acrylic paint or latex paint.
Naturally, you also have the option to paint the concrete planter after it is cured. For more complicated patterns and art, this is advised. If you wish to add texture to the planter, you can use a sharp object to draw lines or other details while the mix is still slightly wet, but after it is hard enough to stand outside of the mould. When it comes to painting the planter, you can use a spray can, regular paintbrush or a foam brush.
The sky is the limit when it comes to decorating your concrete pot, and finding interesting patterns to press onto the outside of the planter will yield impressive results that will add an eye-catching element to your home or garden. There is certainly no shortage of online arts and crafts blogs that will provide you with great examples, inspiration and DIY guides. Do not be afraid to try out new techniques, even if you do not consider yourself the creative type. There is no better way to learn than practise.
Purchasing concrete mixers from BS Power
As one of the most reliable and well-stocked online hardware and machine stores, we at BS Power offer a good range of concrete mixers, with which you will be able to execute your concrete pot projects with ease. It is likely that you will find many, many more uses to your mixer as well. Before making use of the mixer, ensure that you have read the safety and operation manual, and checked out a few of our instructional blog posts on our website.