Outdoor Planter Guidebook
There are houseplants and there are garden plants, and they comprise a huge range of flowers, trees, shrubs, perennials, and annuals. There are some plants chosen just to bring color, scent, and perhaps hummingbirds or butterflies to the garden, but not to remain a permanent fixture throughout the seasons. There are also plants that are not quite suited to the location in which they are grown, and which may need a bit of protection (to both the roots and branches) during wintery weather.
In other words, there are all kinds of plants, trees and shrubs we can choose to grow, no matter where we live. And yet all of these plants share one thing in common (apart from being plants!), and it is that they need the right containers.
We call them planters, but you might hear them called pots, containers, and planters interchangeably. That’s fine, but for the purpose of this book, we are going to talk specifically about the planters that are used outdoors, and which typically remain outdoors all year long.
You might think that there is not much to selecting the right planter, apart from the basic design and materials…yet, there are many decisions that go into choosing just the right planter for your needs. In this guide, we are going to walk you through the process of choosing an outdoor planter that will provide a good home to your preferred plants, perform well for years to come, and look great as it does!
Pots and Planters…Are They the Same?
As we just learned, above, pots and planters are terms used to describe the same items, yet most of us think of a flower pot as a smaller vessel made for use in both indoor and outdoor settings.
Pots, typically, seem to be more portable. Planters, on the other hand, bring to mind visions of larger containers meant to be kept outdoors year-round, and which may be placed in a single location meant to become a permanent home or moved around to protect their contents.
Unfortunately, not all planters are made to withstand life outdoors throughout the course of a few seasons or years.
Life Indoors vs. Life Outdoors
This is a key difference – being designed to perform indoors or outdoors in any conditions – and a defining factor where outdoor planters go. And with that distinction of being able to live indoors or outdoors comes a world of possibilities.
After all, you can put a planter to use on a deck or patio, in the garden or along a walkway, and use it to grow herbs, seasonal flowers, and even hold winter-time decorations like branches of holly, bittersweet vine or even artificial trees and shrubs.
If you wish to simply leave an outdoor planter empty and outdoors year-round, it will be designed in a way to allow just that. Additionally, that outdoor planter will do just fine if toted inside in order to protect the plants, shrub or even tree that it contains.
You cannot, however, say the same for planters meant for indoor use only, or made of materials that just don’t stand up to winter conditions.
Reasons to Buy Planters for All Plants and Purposes
And this is where many shoppers become confused. After all, they wonder, wouldn’t any vessel (whether you call it a pot or a planter) be designed to stay outdoors all of the time?
In a word: No. (And it might shock you to learn just how many people buy large and beautiful pots or planters only to find them broken, cracked and ruined within a year’s time!)
Here’s why: In many areas, the end of the warm weather (usually towards the end of the autumn season) means cold temperatures and then frosty conditions. Frost kills off most plants, and when it turns into freezing conditions, it can actually damage planters not designed for indoor use. Even if you don’t have bouts of freezing weather, the planter NOT designed for outdoor use can degrade and deteriorate quickly.
This is due to a few reasons:
- Winter weather can go through freeze/thaw cycles which can cause even small amounts of water in the soil or even in the planter’s materials to freeze as well. As the temperatures rise and thaw, that moisture does, too. This causes expansion in the soil and the vessel, which can easily lead to cracking and breaking.
- Even if a planter is not made of a porous material, it can degrade in the dampness and trapped moisture of winter weather. A metal planter built for indoor use, if allowed to remain covered in snow or left in a shaded area where moisture cannot be evaporated by a few hours of sunlight, may begin to rust and degrade in the course of a single season.
- Most planters are not easily buried in the soil or relocated to a sunny, southwestern facing wall, in order to “winter over”. This leaves them prone to damage or harm.
- They will be designed to emulate the looks of stylish garden planters and pots for houseplants, yet they will be made of materials that are often lighter in weight and much more durable
- You can find them made of materials that are impervious to ice, freeze/thaw events, standing moisture and damages due to exposure.
- You can even find them in materials that will stand up to being buried or wrapped in insulating materials to allow the plant, tree or shrub to overwinter outdoors.
- They allow you to invest in that planter just once without worrying about a costly replacement a year or more down the road.
- They come in sizes to hold the demurest little houseplants or large trees.
Now that you know to look at outdoor planters for your indoor and outdoor gardening needs, let’s take some time to learn about your choices in planters and materials.
Types of Outdoor Planters
As we go through the types of outdoor planters available, try to keep in mind that not all materials are a good choice. We’ll look at each of the most common options, but we’ll also consider the different pros and cons to using each of them.
You can find them in many shapes and sizes, and often these are what most of us think of first when thinking of outdoor planters. Typically, they will be square or boxy in shape and can be made of long-lasting materials like teak or cedar, which are insect and weather resistant.
Wooden planters are easily some of the most attractive when your garden design has an earthy look to it, or you want to add more natural material to the setting.
Affordably priced, plastic planters are a very common choice in window boxes and other, similar designs. Because there is not a great deal that can be done with plastic planters other than forming them into boxy forms, you won’t see a great deal of variety in this material. In fact, if you are eager to get the durability of a plastic with the good looks of other materials, such as stone or ceramic, you may want to consider resin (see below).
Resin (Woven or Plain)
Resin is a more modern upgrade of traditional plastic and is an authentic all-weather material. That is why you now see so many patio sets and outdoor furnishings made of resin. It is very commonly formed to emulate wicker, and you will also find a nice array of planters in this same format, with the looks of oversized wicker baskets and pots.
This is a material that can be found in such a diversity of shapes, sizes and forms that you may be able to use it within almost any sort of garden design or style.
As one of the world’s most commonly used materials for pots and/or planters, it has a wonderfully earthy appearance, though it can also be molded and formed into the most contemporary styles, too. Heavy and often quite colorful, it is a great way to add a pop of color to a patio or garden area, as well as an interior space.
With its ability to be colored in almost any way, and even take on a metallic or textured finish, it is a great choice for a contemporary or classic garden.
You should be extremely cautious of fuel spills, clean them up as soon as you see them and always double check in case there are more spills. Spotting fuel spills is not easy as bio-ethanol is transparent and does not have any particular smell.
Always keep bio-ethanol away from the reach of pets and kids. We would also advise you to follow some precautionary measures we have given below such as:
Historically speaking, it is ceramics and terra cotta that stand as the most commonly used materials for planters of all kinds. Terra cotta is a clay that comes in an unglazed form and offers a cheerful reddish brown hue wherever it appears. Though it has always been a very popular choice with gardeners, the advent of lighter weight and more durable materials has led to terra cotta-like options being produced in longer lasting materials like resin, plastic and fiberglass.
With its earthy and classic look, it is a wonderful choice in almost any setting, but it will never withstand outdoor life in areas where deep freezes occur – unless entirely protected from snow and ice and thoroughly dried before going into winter storage. You should also always store them upside down to protect them over the long term.
Easily the most variable material in the world of modern planter design and manufacturing. It can emulate stone and concrete, and yet it also works well in even the most unusual shapes, including conical vessels, window box styles, standard round planters, and more.
It can also be found in many textures and colors, making it a material well-suited to almost any sort of garden style, design or purpose.
Modern garden design seems to be the most common way that metal planters are put to use. Made of copper, stainless steel, cast iron, galvanized metal and even bronze, they can be formed into very basic shapes or rather elaborate ones. They can be made to patina over time, or even arrive in that condition. They are popular with rustic garden designers, too, and pack a lot of visual power into a single vessel.
Cast (Stone or Concrete)
Though you may find that planters made of cast stone or concrete are heavier and more costly, their remarkably durability, wind resistance, frost resistance and general good looks make them a very popular option. They are typically made in decorative or even classical forms and look great in a European styled garden or even an earthier garden because of their low-key colors and ornamentation so often inspired by nature.
As an example, you may find some window boxes made of these materials, and they may be accented with vines and scrolls, offering a very organic look.
Pros and Cons of Common Planter Types
So, what are the pros or cons of the different planter types we have just learned about?
Pros and Cons of Wood Planters
Wood may be weather resistant, but it is also porous, meaning it is never meant to last indefinitely. It can actually begin to degrade quickly if it is always damp or wet, exposed to insects, or left in less than ideal places, such as shady corners of the garden. When wet, it is often very heavy. Of course, on the pro side of things, it has a wonderfully rustic and natural look, and even a refined appearance. You can use wood for container or raised bed gardens, and this is actually a very common practice.
If you are eager to have outdoor planters that have the good looks of wood, a wonderful option might be a set of planters designed to emulate wood but made of weather resistant materials. Window box inspired planters are also a good option.
Pros and Cons of Plastic Planters
Plastic is not porous, and so a lot of people think it is impervious to the weather because it will not absorb water. While some forms of plastic may withstand freezing temperatures and the rigors of freeze/thaw cycles, not many of the more affordable products actually last that long. Why? They are not designed for baking in the sun and then freezing in the winter weather. The plastic becomes rigid and will crack or break rather easily.
Additionally, if you leave soil in a plastic planter, it is going to undergo the freeze/thaw issues, bloat with lots of water at any time of year and end up cracking the weakest point of the plastic.
We suggest you consider resin or fiberglass planters, rather than plastic, if you want a super durable options with a lot of flexibility in texture, style and design.
Pros and Cons of Resin (Woven or Plain)
There are a great many pros with resin and very few cons. This is a non-porous material that does not absorb water, but it is also totally stain resistant. It weighs very little and retains its color even when exposed to summer’s sunlight and winter’s cold. It never corrodes or cracks, and you can find it in a wide array of shapes and styles. It works in almost any sort of garden design and looks good indoors or out. Lastly, it is a material where you may see your investment stretch for decades rather than just years!
The only con is that it is not used to make all styles or forms, and this means you may not easily find the precise look you want.
Pros and Cons of Fiberglass
As one of the most popular materials, there are far more pros to fiberglass than you might expect. For one thing, it has a fantastic insulating quality that allows plants to remain much more stable in colder weather conditions. The material also helps to retain moisture in the soil. Lightweight and very easily moved (even with soil) it is not a material prone to breaking or cracking in even very low temperatures.
Fiberglass is also able to be shaped into every conceivable form, and yet ask for almost no maintenance or upkeep. Instead, you can invest once and find yourself able to use and re-use the same fiberglass planters from year to year.
If there is a con, it is that many people expect fiberglass (with its light weight, many colors, and plastic-like feel) to be as low-priced as plastic. It isn’t, but as we already mentioned, it is remarkably durable and so you won’t be spending repeatedly to replace them as you do with plastic.
Pros and Cons of Glazed Ceramic
We have already discovered that ceramics can be porous if they are not glazed and baked at high heats. This means they are not always a good choice for outdoor use. However, there are some definite pros in using them. For example, some argue that they are heavy and that this must be a negative. However, if you are using them with trees or shrubs, that counterweight at the base keeps your plants upright. They are protected against extremes of temperature because of their thickness, and yet their glazing allows them to hold moisture, which may otherwise readily evaporate in the summer’s heat.
Sadly, many are made with a single drainage hole at the bottom, meaning they can become boggy, and there is that issue of cracking in the winter weather. Their weight can be a negative, too, if you try to move the pots or simply re-pot a plant or tree.
Pros and Cons of Terra Cotta
Though it is tough to argue against the beauty and perennial popularity of terra cotta planters, there are quite a few cons to the different pros. Let’s begin with the upside – it is a good looking material that offers a porous finish that prevents plants from being boggy or over saturated.
However, it can be quite fragile, have only a single drainage hole, absorb water and dry out a plant, and it won’t withstand winter freezes. You will find yourself buying replacement planters a great deal more often with terra cotta than other materials, though, if you do prepare them (putting them along a protected, southern facing wall and insulating them against the deep freezes), they can offer a good solution.
Pros and Cons of Metal Planters
The downside of using long-lasting and rugged metal planters is that they allow a lot of heat transfer. This means your planters can become too hot in the summer and sustain a lot of frost or freezing damage in the winter. They can also be made with flawed materials or finishes and end up rusting and degrading quickly. The upside is that you can use internal liners with them to protect against the high thermal transference, but this will not prevent problems with heat or rust.
Pros and Cons of Cast (Stone or Concrete) Planters
As already noted, one of the only negatives about a cast stone or concrete planter is the fact that it can be quite heavy. This may mean that you must use it specifically or exclusively for seasonal planters and annuals that you do not intend to see again in the coming spring. You may overcome that limitation, however, by opting to place a planter of this kind against a southern facing wall, and then buttressing it with insulating materials before heavy cold arrives.
Making Your Choice
Is there one type of planter or material that is the best? No, because there are too many factors that determine just why you might select a specific type of planter.
Of course, it is not only about materials and the pros or cons each offers. While you may be driven towards one specific material for its affordability and another for its long-lasting qualities, you need to think about a few more issues. Let’s consider them, below.
Plants and the Right Planters for Them
“I want a good planter for some bright red geraniums by my front door.”
That sounds like an easy thing to find. After all, you will look at the exterior of your home and its style, the color of the flowers you want to plant, and the height you want the flowers to be as visitors pass by. That’s it, right? No, as we just learned you have an array of choices in terms of materials, and you can consider how each of them may or may not give you what you want.
There are also a few additional factors you have to weigh as you make your final choices.
Three Rules for Choosing Planters
Below are three of the most vital factors in the success or failure of your planter selection process. You’ll see that we noted most of them in the various pros and cons or materials descriptions in the previous section. But here, we have to stop and give them a bit more weight in the actual decision making process as they are incredibly relevant to the way any planter looks, performs and lasts over time.
Total Weight and Mobility
It may seem logical to begin by thinking about what you will grow (something we look at further a bit later on in this chapter), and then you can weigh the importance of a planter’s weight and mobility. For now, though, it’s important to just figure out why total weight and mobility matter.
Total weight is the weight of the planter, the soil, the drainage materials, the pot and the plants themselves. You should always take the time to do a bit of quick math and calculate total weight – even if you won’t relocate a planter – because you may be keeping planters in an area that shouldn’t hold heavy weights. Balconies, decks, terraces, rooftop gardens…these are places where total weight is very important.
Remember too that any taller plant (such as a tree or shrub) may be at risk of tipping over if kept in an area with windy conditions. A heavier planter may be your ideal solution for keeping the tree or shrub safe from damage.
The weight also determines the ease of mobility, or whether or not you will require help to pick up and move planters to another area. Whether you like to reorganize your container garden, or you need mobility because of winter conditions, the total weight is what helps you determine if you can move the planter, but so too does its material and design.
A vulnerable plastic planter full of heavy drainage materials, soil and plants is likely to break if moved. A fiberglass or cast concrete planter, on the other hand, can with stand this, and if you worry you are unable to lift heavy weights, many planters can be set on casters or specialty platforms with casters specifically for mobility.
So, take the time to look at a planter in terms of its total weight when full of soil, drainage, plants and even water. Then, consider if it is going to be a bit of a bear to move or if it is even impossible to move without damage.
All potted plants have to have adequate drainage, and depending upon what you grow, that drainage may include one or more layers of gravel, sand and other materials. Naturally, this drainage material is only effective if the planter itself has enough drainage of its own. This simply means that there are multiple holes spread out evenly along the bottom of the planter.
This will allow excess water to drain away and deliver adequate oxygen to the roots, keeping the plants healthy. Be sure that you check the specifications of any planter to ensure that it will allow your plants to be kept safe from smothering in too much water. After all, outdoor planters are kept, well, outdoors. A single heavy rain may bring down enough water to drown a plant if there is not enough drainage in its container.
Many pots have a single hole in the bottom, and if you find a planter with such a limited amount of drainage, it may not be a good choice. If the opening is large and you are using drainage material, it could suffice, but if the planter sits directly on the ground or the hole becomes blocked, it can be a problem. It is best to choose planters with multiple drainage holes.
We have looked at porosity a bit when talking about planters made of plastic, ceramic and terra cotta, among other materials. Essentially, porosity means the ability of a planter’s materials to let both moisture and air pass through. This is important since all plants need oxygen around their roots, and they also need water to be able to move away or evaporate in order to maintain a good soil temperature and prevent plants or roots from rotting or developing fungus or bacteria.
However, a very porous material runs the risk of drying out very quickly and on an almost daily basis. While you could choose a potting mix and drainage that helped to slow this, if you are unlikely to do daily watering or you live in an area of intense sunlight and summer heat, porosity has to be a major factor for you to consider.
Adding It Up
Does your planter need to be moved?
Will it allow adequate drainage?
Does it require porosity or even the avoidance of porosity?
These are major issues to use as you first set out to choose a planter. Then, consider these other key factors…
Other Key Considerations
By now, you’ve already heard about this in many different ways. We’ve spoken about materials that are fragile, and therefore not at all durable. We’ve considered materials that can or cannot hold up to extremes of heat or cold, snow or ice, wind and so on. We have also looked at materials that are able to retain their color, resist UV or sun damage, and remain flexible rather than turning brittle. We have also considered materials that can provide a less than ideal planter (such as a ceramic planter fired at very high temperatures) with cold resistance.
Basically, durability is all about the expected life span of the planter, and it always has to do with the type of materials you choose AND where the planter is located.
It also has to do with the type of plant you are growing. Why? Because you may need durability to mean a single season rather than many decades of service. For example, you may be growing a small or dwarf fruit tree that will transplant into a final, much larger container, a year or two after it is first planted. That would mean a less durable planter is needed. In fact, it could be that you keep the young tree in a nursery pot until it is ready for its final home.
That means that durability is a bit relative and you will have to figure out what your version of durability means to make the right choice. It will have to do with those issues already mentioned – how long you expect a planter to last, where you are putting it, and what you’ll grow. And with yet another mention of “what you intend to grow,” let’s look at that as a factor for consideration when choosing a planter.
What Are You Growing?
You won’t use a planter for things like seed starting or transplants because it would be an inefficient use of space, soil and resources. However, you do have to give serious thought to what will reside in any planter you are seeking.
Why? As we have already considered, if that plant is to remain in place for many years, you can choose a heavier, less mobile planter. This means you can choose a larger planter, too. But you don’t want to pick a difficult shape that can make re-potting a challenge.
If you are going to grow temporary or seasonal plants such as annuals, vegetables, herbs and other similar items, your choices are entirely different. Perhaps a window box style of planter is a good idea or maybe even a broad and wide-mouthed urn with cascades of flowers tumbling around?
And though the world of plants is seemingly endless, in the end, there are really only two main categories of use where outdoor planters are concerned, and we’ll look at the special demands or needs for each of them, below.
You will need to give a great deal of thought to almost all of the factors we have considered in this chapter as you choose a planter or two, or ten, for your container gardening. Here are some of the main issues you’ll want to focus in on:
- Is it all about annuals or is it an assortment of plants? If you are going the annuals-only route, you can choose less mobile options. On the other hand, if you are investing in perennials, they may need materials that are insulating, lighter in weight and more mobile.
- Are you going to be making permanent garden designs with the planters? For example, maybe you are using a more formal plan and require urns and classically designed vessels? Maybe you are doing a rustic, raised garden and need planters that coordinate with that space, and which can stay in place once you layout the garden?
- Do you have a color scheme or garden design in mind? Will it be all about green herbs and colorful planters? Maybe you have a collection of annuals you want to arrange in different vessels or very organized containers? Give thought to heights, spacing, colors, and seasons to make the right choices. You can do a great deal with your planters and plant combinations!
- Are you doing standard and vertical gardening? There are many options for vertical planters, urns and taller planters, and you should not overlook your ability to choose many heights, designs and even textures or colors as you can make planters a major part of the design.
- Where are you doing the container garden? This is all about durability, porosity and drainage. If you are keeping planters in full sun, be mindful of the amount of watering you will find yourself doing. If they are in full shade, be aware of drainage and porosity which can stifle plants without a way for water evaporation to occur.
Growing trees in containers is a much easier matter to consider because it boils down to a few simple questions or concerns:
- How tall is this tree or shrub going to be? If it is going to be tall the planter needs to be quite bottom-heavy to help give support
- Does this tree or shrub require winter protection? If so, choose a planter that will adapt well to movement and/or the use of casters to allow you to easily push it into a southern facing corner where it is sheltered from intense cold and damage
- How large a root ball will this tree typically develop? You want to “go big” with trees and shrubs to allow them to form a root ball of adequate size. There is nothing more frustrating than trying to transplant a large tree into an even larger planter.
In general, it is best to invest in a premium quality planter for a tree or shrub. This ensures you won’t need to worry about risks of breakage, inadequate drainage or difficulty in mobility. For instance, you can easily find cast concrete, fiberglass or resin planters that are beautiful in design, available in huge sizes, and lighter in weight, but which can really help give a tree or shrub a happy forever home!
Regardless of what you might see or hear, your opinion about the appearance of your garden planters really does matter. In fact, the looks of any design or decor matters. If you groan with dissatisfaction each time you look at your garden, patio or a single planter, it is not acceptable.
So, take the time to consider your preferred aesthetic style. Is it modern and contemporary? Is it rustic and earthy? Do you prefer Classical designs inspired by Ancient Greece or Rome? Maybe an iconic European garden is your inspiration?
No matter what, you’ll find many planters to meet such preferences. The point is to add that style or aesthetic into your decision making process.
Low maintenance planters are really ideal, and that means a few things:
- Choosing a material that does not need annual “treatment” such as applying stain or repainting
- Opting for materials that resist UV rays that can cause them to fade, weaken and break down
- Looking for planters that can resist insects and other pests that cause damages
- Choosing planters made of easy to clean (and keep clean) materials.
Basic Planter Care and Troubleshooting
It would be ideal if basic planter care was required just once a year, but it can be an ongoing matter. Basic steps include a drainage check, protection, and cleaning.
Double checking that drainage is still moving smoothly. Do this after a heavy rain or after watering well. If a drainage hole is blocked, you may find that you can unblock it by carefully leaning to one side and using a dowel to clean out and unclog the holes. Unfortunately, if it is due to soil compaction, you will find yourself having to un-pot and then re-pot after removing the soil, drainage and beginning with a clean slate.
Using a good winter protection system, whether you are in a location where the winter means deep freezing or even just heavy rains and winds, is always wise as it offers planters seasonal protection.
This means you may need to relocate the planter to a south-facing area and up against a wall. You can group planters together in such places and even dig a small trench for smaller planters to offer them even more protection from freezing and thawing cycles.
If your plants are perennials, trees or shrubs, you’ll want to protect them, and one of the best methods is to build a small shelter with metal garden stakes and chicken wire (effectively building a temporary fence around the planters and plants). Fill this with autumn leaves, mulch or marsh hay.
You might also wrap trees and shrubs in the same manner, but instead of using chicken wire, use burlap and skip filling in the space. If you use metal containers, they need to be sheltered from snow and rain or they may rust. You can do this by wrapping them in plastic tarps and securing them before moving them to another sort of protection.
If you have an unheated porch or three-season room, this is also a great spot to relocate potted plants and trees.
Any planter that usually sits on the ground should be elevated from the ground on a few 2x4 boards or a formal platform during the winter months. Regardless of the material, sitting in contact with the soil and standing water can cause damage to the plants or even the planter.
It is a good idea to always empty and bring in planters prone to winter damage OR use this as a time to clean planters that will be emptied for the winter.
It is a good idea to discard soil every other year and allow your planters to be emptied over the winter months. When you do remove the soil and drainage, it gives you a good opportunity to properly clean and disinfect them.
And though you may dislike hearing it, you will need to clean almost all planters every few years. The exception is the planter with a perfectly healthy tree or shrub. To clean a planter of any kind, you simply empty it and follow these steps:
- Use a soft bristled brush to scrub away any soil that clings to the inside or outside of the planter.
- Hose it down and let it dry in the sun for an hour, or so.
- Use scrub brush or dish cloth and warm soapy water to give it an initial cleaning. Then repeat this using white vinegar and allow to dry completely. If your planters are made of wood, fiberglass or resin, you can stop here and move on to the last step.
- If your planters are made of concrete, clay or terra cotta, you need to take one more step. Make a solution of nine parts water to one part bleach, and carefully soak the surfaces of the planter with it. Rinse after 30 minutes and allow to dry completely for 24 hours.
- Place new drainage and soil in the planters and restore the plants, shrubs or trees to their home.
So, what kind of garden do you have in mind for the coming year? Hopefully, this has all inspired you to begin using a few planters in the garden, patio, terrace, porch or just about anywhere else!
Planters work in the full sun or full shade and can be used to even create outdoor living spaces or little islands of privacy. You can create an entirely different space with a few well-chosen planters and even give yourself more room to garden than ever before.
Have fun choosing and then using outdoor planters and remember that the more time you take in choosing them, and the better the quality you select, the more seasons of beauty they can provide.
Good luck and happy gardening!