GFRC Concrete Planters, fiberglass reinforced concrete, are a durable solution for streetscapes where additional weight is required.
GFRC Concrete Planters, at six to seven times heavier than fiberglass planters, are still much lighter than concrete planters with problematic steel rebar reinforcement and a lot more durable.
GFRC Concrete Planters are created by adding long-strand glass fibers and woven mat to concrete. This strengthens the material, decreasing the required thickness. Fiberglass decreases the thickness by 60% (from typically 3” in cast concrete to 1” in GFRC Concrete) directly reducing the weight by the same amount.
More importantly the fiberglass eliminates the steel rebar that eventually rusts and breaks the planter apart from inside through a process called spalling as the rusting metal expands as you can see by following this link to Planter Selection where you will find detailed comparative information about all planter materials and construction types.
There are two primary reason to choose GFRC Concrete planters. First, they are very strong, heavy, and rigid. Second, they offer the aesthetic choice of the two different finishes – travertine and acid etched. The travertine finish has a rustic, puckered appearance. The acid etch has a consistent, fine sand texture. All colors are integral to the material and will effectively hide chipping and scratching.
As a high volume national distributor of Tournesol Siteworks products for the past 15 years DeepStream has had a very good experience with their entire modern GFRC Concrete Planter line. Tournesol has an extensive product line of commercial grade planters that Landscape Architects and landscapers have used for 30+ years. They back their GFRC Concrete Planters with a 3-year warranty.
Click on the the pictures or the link below to see more information on commercial GFRC grade Concrete Planters and place orders. DeepStream Designs.
DeepStream Designs knows from projects with Landscape Architects across the country how important using the appropriate planting mix is when growing perennials, trees, and bushes.
Replanting these heavy items with complex root systems will be problematic. Getting it right the first time is well worth the effort.
Often clients use their “Landscaping Contractor” for this work. This may be a good solution if the contractor has extensive experience with container gardening and knows the value of selecting the correct planting mix. Otherwise it could be a mistake.
Why? Many Landscapers are not familiar with using a planting mix as they are usually planting in the earth. By using “dirt” or “soil” it may make the planter too heavy for the load on a roof or balcony.
Dirt, or an improper planter mix, will prevent drainage if it contain clay fines that can block drains, may hold too little or too much moisture. Additionally, dirt might not contain the correct PH and initial nutrients for the plants that you’re going to use.
There is no universally correct planting mix, as area microclimates must be taken into consideration. Selecting a planter mix requires an intimate local knowledge of the complex relationship between all the competing factors for beneficial plant growth and maintenance. Therefore, it is essential to ensure that you have a reliable source for your planting mix.
We have posted a blog on the long-term cost benefits of using a Landscape Architect for even small commercial projects but you still need to ensure they have container gardening experience. Another reliable source may be the nursery where you are sourcing the plants.
Whatever you do, don’t assume that your Landscaper or other source has the knowledge necessary to provide the planting mix. Before starting, ask about their experience with container gardening and what mix they propose to use. Vague or generic answers should be your clue that you need to investigate further before proceeding.
By all means, make certain that whoever does the planting follows DeepStream’s instructions regarding planter drainage using drain pads and filter material. Many “old timers” fall back on gravel and holes in the bottom which will soon clog.
Remember that most of DeepStream’s stock planter liners come with just one threaded drain hole. This is only the minimum, since some installations are inside and require the hole to be plugged or drain pipes attached. One hole means one point of failure with no backup.
DeepStream will drill additional drain holes required by your installation at no charge. Tell us where you want additional drains installed, and we will do it before shipping. You may also add them in the field with a hole saw. Deepstream can supply screw together flange fitting to add straight or 90 degree hose barbs to new holes you add.
Water in, water out. Simple, right? However more plants die from lack of planter drainage than under watering and it’s an expensive, time-consuming, waste of time to deal with poorly draining planters that ultimately have to be dug up and remedied.
Planter drainage is often the weakest link in the delicate balance of nature required to maintain planters and container gardens. This article on planter drainage will present the simple physics, costs, and benefits of advanced drainage system alternatives you should know before installing plants in planters.
If your interested in where drainage falls into the larger overall consideration of planter design and construction click here for details on Planter Selection. The solution ultimately comes down to the design of the waterproof planter liner, or container, design, drain placement, and blockage.
For those of you who have not had the benefit of walking the trade show floor at a Landscape Architect conference, or who did so without this aspect in mind, I will introduce a “high-tech alternatives” that I am incorporating as options into planters I design for DeepStream Designs. Click: for printed instructions on drainage.
The Drainage Problem
As a Developer and Property Manager I had to deal with planter drainage problems in large built-in concrete planters, and properties with lots of medium-sized stand-alone planters. I can tell you that it is an expensive, time-consuming, and demoralizing task to deal with poorly draining planters that ultimately have to be dug up and remedied.
As prevalent a role as solar gain-induced thermal shock to root systems plays in stunting or killing container-grown plants, the lack of efficient planter drainage is a far more common reason for failure, at least in rainy climates. Water-soaked roots from a lack of proper planter drainage can kill a plant in less than 24 hours, whereas baking and steaming roots in a single-wall planter or pot can take weeks, or even months, before the plant finally succumbs.
Here in Florida, storms can dump 6″ of rain in just a few hours, so it is easy to overwhelm a poor planter drainage system, and you can literally see containers overflow the top. However, long periods of drizzle and gray sky, conditions found on the west coast, combine low evaporation with soaking soil which also subtly builds up fatal water levels in containers without an effective drainage system.
Drain size and blockage
The primary reason for water build up is a malfunctioning watering system, combined with a drain clogged by dirt or roots, NOT too small a drain.
Given that a planter filled with nothing but water 6″ deep will drain at the rate of about a cubic foot per minute through a 3/4″ opening, no amount of rain alone will overwhelm a properly functioning planter drain. Single-point drains of this size are convenient to use for inconspicuous controlled planter drainage systems on balconies, rooftops, and courtyard patios. The key to making this work over the long-term is technology and design.
Issues with built in planters drainage
If you have read the Blog article on Planter Selection and Design, or looked in-depth at the DeepStream Designs’ website planter section, you may remember that the reason I ended up designing free-standing planters was to avoid the structural problems associated with built-in planters: waterproofed planters built into buildings with poured concrete will at some point succumb to settlement cracks, as well as drainage issues. Even the best sprayed, rolled, or troweled-on concrete liner systems I have seen will leak at some point in time, and digging in them doesn’t help.
So if you have plans for specimen plants, or are planting trees that will grow too large for workers to lift by hand, make sure you have crane access to lift the trees, or some way to get forklifts or other types of equipment like tripods in to lift the plants out of the planter for repairs, or to bring in new ones should major plants die.
Avoid building or buying planters or liners with drains in the bottom where you will have to remove large plants to get at them. Install a vertical 2″ PVC pipe up to the final soil level, with a removable top to keep soil out, before filling the planter with soil so that you can pump water out in an emergency before the plants drown.
Proper planter drainage is the element that the container industry is least likely to talk about, because it is relatively complex and is not readily “packaged” for sale. Making potential customers of larger pots and containers aware of drainage issues is seen as a negative sell, so it is brushed off with instructions to “Drill a couple of more holes in your pots.” This is an area in which DeepStream can bring great added-value to its customers.
With that said, the advice to drill more holes falls into the “Just because they said it doesn’t make it not true” department. It is, in fact, the most cost-effective approach for smaller, easily re-potted plantings that you can lift out, in pots which slope evenly outward as the pot wall moves towards the top. This simple classic form facilitates the removal of the plant to clean out blocked drainage holes without damaging either the pot or the plant. Essentially, you are pre-planning for blockage by increasing the size of drains that will be clogged.
Free standing planter drainage
When considering free-standing planters, and larger planter liners hidden behind a decorative facade, keep them small enough to work on. Break the planted area up using multiple overlapped liners, rather than one big liner with one point of failure and lots of plants to remove to find the problem, or to die in the event of a catastrophe.
It is not just the cost of the plants to consider, but also the considerable disruption and effort to find and remedy the problem. There is also the mess to clean up, especially on rooftops in urban areas, and the potential for cosmetic damage to the building by workers during the process.
Soil mixture is a critical consideration, both for the plant and the building weight limits, as we often find on rooftop and balcony projects. You are looking for soils that will hold nutrients, PH, and moisture within fairly specific ranges that best suit what is being planted, while at the lowest possible weight. Very seldom is “dirt” just dumped into a container.
This soil selection process, done right, eliminates much of the problem caused by “fines”, the small clay-like particles that block filter membranes. Use perlite to increase drainage rates in wet climates or it’s opposite, vermiculite, to retain water in dry climates, under balconies or indoors.
Another drainage consideration is filtration and root blockage. A planter is really just a shaped French drain. Small particles of clay (fines) are carried by the gravity-induced water flow downward towards the drain. Unfiltered, these fines will block any filter membrane in a remarkably short time. The standard way to create a rough filter well area is to fill the bottom of a planter or pot with a few inches of gravel over a bottom drain.
One key design factor of DeepStream planters is that they uses a liner within a decorative facade. This not only prevents solar gain, but also hides drip irrigation lines and the drain. This is important in aiding filtration because the drain does not need to be limited to the bottom of a pot as it will quickly clog.
When considering drainage for large planters, and which planter forms to purchase, the first step is drain location: Realize:YOU WILL HAVE TO DIG UP OR REPOT YOUR PLANTERS SOMETIME!
Yes, that’s the dirty secret. It is inevitable. The question is: how long can you go between major events. Even though drainage issues can often be fixed with the plants in place if the planter liner is properly designed with a taper form wider at the top, as DeepStream’s are, it is much more convenient to avoid them, and less costly over the long run as well.
DeepStream’s liners locate the standard 3/4″ drain a couple of inches up the sidewall creating a “well” below the drain. Fines tend to settle down into this “well”, as water flowing towards the sidewall drain tends to be very slow under most circumstances, so most fines gradually work their way to the bottom. The well also acts as a small water reservoir for the larger roots.
Advanced drainage solution
DeepStream’s advanced drainage system includes a 4″ by 6″ drain board (think of a thin, uncrushable egg crate covered with geo-textile covering) to increase the drainage surface area. The drain board comes hot-glued over the drain. When adding the plants to the planter, be sure not to compress this drainboard against the side of the planter wall with a force or a hard root ball, or it will act as a perfect seal against the drain and stop all water flow. Additionally, there is a roughly 2 sq ft piece of weed block fabric to be folded over and placed over the drain board as further protection against penetration by roots.
Weed Block, as geo-textile is often marketed, is a misnomer. The “30-year commercial landscaper” variety you see at the large home centers will have roots growing through it in less than 2 years. That said, it still helps delay the inevitable, and DeepStream still provides it with the standard drainage kit.
It is highly recommended that the geo-textile fabric is kept in place by the very important filter of at least a 2″ thick covering of very clean, very coarse sand of between 1 and 2 mm particle size. For reference, the wire of a medium paper clip is 1 mm. While very coarse sand is hard to find, it is the best filter, although it does nothing to block root penetration. Masonry or playground sand is too fine and will compact and prevent drainage; pea gravel lets too many fines through, and they will block the filter fabric.
One good and available material, though not perfect, is Paver Base and Pearlite found at Home Depot. Most of the grains in Paver Base are large enough, but it still has a lot of fines in it but it keeps the Perlite in place well when potting. The well in DeepStream’s commercial grade planters is plenty deep to handle this without clogging the drain.
Technology Enhanced Filtration: Two Steps
The most important aspect of new drainage technology is in preventing root blockage. DeepStream now offers an optional root control fabric, BioBarrier (TM) with a plastic-embedded non-systemic herbicide, with a lower toxicity than table salt or aspirin, that creates a 2″ thick root deflection zone around the drainage material by preventing root cell tip division. The product, guaranteed effective for 15 years, has been used as a weed control system for more than 35 years in agriculture to prevent weed growth between row crops. Now, with proper filtration, one should be able to go 15 years without digging up a planter, usually a job performed every 2-3 years in heavy rainfall areas.
Giant sports stadiums and golf courses, with millions of dollars at stake if drainage fail use high-tech crush-proof mats of plastic tubing covered with geo-textile to ensure a large drainage area and directed water flow to prevent damage to grass and delays in play caused by flooding.
DeepStream now offers this same advantage in its single-point directed flow system uniquely adapted for balconies, roof gardens, interior courtyards and other areas where drainage control is required. This is lighter, more effective, and allows for deeper planter medium than less effective gravel systems.
There are several issues to consider when choosing a garden planter. Start with aesthetics, how it functions, and the cost value relationship.
In some difficult situations such as high winds where stability is paramount, or south and west facing locations with intense sun where there needs to be a air gap between the planter box and the liner to keep the root ball from overheating, you will have less options when choosing a garden planter.
You also need to determine the types of plants you want and what their soil, drainage and watering requirements are. Local Landscape Architects, landscape maintenance companies, or your local nurseries can give you good advice.
When choosing a garden planter remember that it will affect your choice of plants which is determined by soil volume as well as sun and watering requirements All these consideration directly influence the planter liner depth and width so that your plants grow well as they mature and will not require a lot of extra maintenance.
If you’re thinking of planters that require a waterproof inner liner, pick a planter with a stock molded liner size first, otherwise you may find yourself limited to more expensive custom-welded liners. While all wood planters require a seperate waterproof liner not all wood planters are alike.
Wood planters built with carpenter techniques will fall apart in 3-5 years while DeepStream’s 3-component wooden planter systems have a Lifetime Structural Warranty. Longevity is provided by a hidden structural aluminum frame mounted to proprietary trademark anodized aluminum legs, no paint or powder coating to fail, which are engineered to contain the woods countless wet and dry cycles over decades. The systems has a separate waterproof liner with advanced drainage to prevent contact between the wood and planting medium while also providing an air gap to prevent solar gain from overheating the root ball, the gap can also be used to hides drip irrigation lines and electrical conduit for lights.
Follow this link to review the comparative attributes of the various planter types to consider when choosing a garden planter, including wood, fiberglass, concrete, metal, ceramic and plastic: https://planterblog.com
Functional considerations for choosing a garden planter and plants, to name but a few, include:
What are the dimensions of the space you have for planter placement?
Do you need long planter runs or individual planters?
Will the planters be placed on the ground, or on a building level that has weight restrictions?
Will they be placed on a hard or soft surface?
Will they be in a sheltered or windy location? Stability is a function of form.
Will you be planting annuals or perennials? This will affect your choice of planting medium.
What is the planting volume (liner size) required for the plants to thrive?
Will the planters be located where they are easy to install and maintain, or will you be moving everything through lobbies and elevators where permission will be required and other residents inconvenienced by your installation and repeat installations should your planters need to be replaced in a few years?
For assistance in choosing a garden planter, or answering these and any other questions you might have, feel free to call Sheila at DeepStream, 305 857 0466 and we will walk you through our 32 point check list designed to save you time and money or go to www.DeepStreamDesign.com
Which ever planter you decide to go with take these considerations into account as they will greatly affect the success of your garden and gardening experience. More detailed information on the key aspect of successful container landscaping can be found on these additional subject pages:
DeepStream Design’s rugged plastic planter liners make spring conditioning easy.
Perennial plants grown in planter liners have special needs. With spring here in Miami, I’ve noticed that it’s well past time to repot some of my smaller ornamental plants. Others plants like Clusia have very aggressive roots and liners need to be removed and roots trimmed every year.
You need to remove plants from their planter liners periodically to alleviate their root bound condition. This give you the opportunity to add fresh potting medium. You will also check that the liner is draining efficiently. DeepStream Designs rugged plastic liner is flared making this a easy with just a few tools: A long serrated knife, perhaps scissors, a tarp, a broom, and dust pan. Cut off the bottom third of the root system, then break up the root ball as much as possible.
I’m using rubber mulch this year in my drainage plan for ornamentals, but not in my herb or citrus garden planters. because it is lighter than pebbles or gravel used in traditional drainage plans. This makes it ideal to reduce the load on your balcony or rooftop if you don’t need the weight of gravel to keep your pots from tipping in high winds.
I use rubber mulch to fill the bottom of my pots and liners up to the level above the top of my drain, about 3”-4”, after I put in DeepStream’s drain pads (drain board, Bio-Barrier to prevent root blockage, and geo-fabric sandwich) in place over the drain hole and cover that with 4” of Paver Base (very coarse 2mm sand) or even rubber mulch in a pinch as I did this year.
Your potting medium will depend on your climate and your plants, as well as the type of drainage and watering system you’re using. We use drip irrigation and mist sprayers on timers. In Miami where we can get 6″ of rain in 6 hours I use a fast-draining medium to which I add perlite and paver base to further increase drainage rates. You tailor your soil in dry climates by adding vermiculite to retain moisture .
I installed micro valves on every planter liner so that I can adjust the rate of watering for each planter liner. Reduce the flow to the point that water does not seep out the drain except when it rains.
Click on the picture to go to DripWorks website to order all the parts you need to install drip irrigation. It’s a very informative and complete website, cost competitive, and their system are plug and play easy to install.
Repotting large plants:
With the Clusia the the steps are almost identical.
Removed the plant from the liner to trim the the larger roots easily, The tapered shape of DeepStream liners makes it easy to simply slide the root ball from the liner to trim and replant.
Before repotting add a DeepStream’s 3 part-part planter drain pad with Bio-Barrier over the drain holes to aid in root blocking and to retain the planting medium and slow the flow of the water towards of the drain.
Hold the drain pad in place over the hole, fabric side against the hole, with paver base or similar coarse medium, never sand, with out any clay in it. You can even use rubber mulch in a pinch.
With all the roots trimmed for the year your plant and planter liner shape should be restored for another year.
Selecting tapered planter liners with the drainage features your project requires will save you time, money, and effort. Read more specifics about Selecting-planter-liners and here is a video link showing how quick easy it can be to replant.
Boston’s Green City Growers working with the Boston Red Sox and Fenway Park brought Fenway Farms container garden to Red Sox Nation and give back to the Community.
A container garden, installed and launched for opening day of the 2015 season, Fenway Farms’ 5,000 square foot roof deck over the Front Office provides fresh, organically grown vegetables and fruit to Red Sox fans dining at Fenway Park’s EMC Club restaurant.
Not just for show, a meaningful 5,900 pounds of fresh produce – everything from kale to broccoli to hot peppers – are harvested from the container garden each growing season at innovative Fenway Farms to give back to the community!
Green City Growers partnered with Recover Green Roofs, to bring farming to the roof of Fenway Park. Recover Green Roofs is the Somerville-based green roofing company that installed Fenway Farms. Recover Green Roofs was responsible for getting the soil on the roof, while Green City Growers is responsible for the farming operation. Donations to the community are handled by Lovin’ Spoonfuls.
Around the corner on the Strega Deck, more produce is grown in an upscale event space behind the private corporate suites. DeepStream Designs, founded to provide an alternative to the wasteful use of tropical hardwood lumber, was selected to provide the light-weight, cost saving multi-section aluminum planter frame system fitted with recycled HDPE lumber planks, recycled from milk bottles.
These attractive container garden planters have an internal plastic liner and hide drip irrigation lines, and their aluminum structural design ensures the planters will last for decades. The liner-within-the planter design also provides a thermal break so that the root systems never overheat from solar gain.
The Strega Deck opened in 2016. It is a Fenway Farms-inspired event venue that is rented out as part of ticket packages and for special events. The produce grown on the Strega Deck in container gardens is donated to the community by Green City Growers’ food rescue partner, Lovin’ Spoonfuls.
DeepStream Designs is a Miami-based design and manufacturing company using American craftsmen to build these durable planters for container gardens, as well as recycling and trash bins, and a host of custom products, all of which feature a Lifetime Structural Warranty.
DeepStream’s modular planter design is a result of DeepStream’s commitment to Environmental Stewardship which uses the principles of Sustainable Design. This approach ensures the lowest total impact on the environment over time as well as the lowest total cost of ownership while making it easy to install, correct mistakes, and adapt to changing needs.
DeepStream has partnered with Trees for the Future to plant 50 trees for every planter sold and 100 trees for every bin. DeepStream has now planted more than 375,000 trees through this extremely efficient non-profit. For more information check out Trees.org.
Garden planters for privacy on rooftops and balconies can also hide unsightly objects and provide a windbreak.
DeepStream, your planter expert, sells Garden Planters for Privacy factory direct and back them with a Lifetime-Structural-Warranty. DeepStream’s planters use trademark proprietary marine anodized aluminum extrusions that accept wood planks, aluminum slats, plastic panel, or even glass for screen walls that set up quickly.
Using DeepStream’s large wood garden planter for privacy screen, and matching wood trash bins, these owners have made a cozy Manhattan rooftop patio that will endure for decades.
DeepStream Mariner planters are a 3-part engineered system for maximum longevity and landscaping health. Trademark marine anodized aluminum extrusions provide the structure for a hidden aircraft aluminum frame that contains the tremendous forces of the wood as it goes through an endless cycles of wetting and drying, expanding and contracting, that tears apart carpenter built wood planters,.
The frame is engineered to mount options like gates, casters, and planters with trellises which make colorful screen walls for privacy.
The wood, or recycled plastic lumber, planter boxes protect the roots in the liners from over heating due to solar gain as can happen in single wall fiberglass, metal, or plastic planters and pots.
The rugged waterproof plastic liner with advanced drainage protects the wood planter box from the soil and the plants from drowning. Drip irrigation lines can be hidden between the liner and the planter box.
Long runs of planter anchored screen wall are easy and cost effective to erect even on urban rooftops. Modular design allows each section to be set up in 10-15 minutes, all you need is a Phillips screwdriver and a 7/16″ wrench. All parts are replaceable at direct factory cost should a part ever be damage.
Because the planters are pre-assembled using an inner frame and legs of marine anodized aluminum there is no messy installation as with carpenter built wood planters and less materials have to be moved to your roof or balcony.
The modular design also mean that you can use the elevator or even stairs to move your planters to the roof, not cranes.
Condo owners with a balcony can also use planters for privacy by anchoring a full screen wall.
Fiberglass Planters offer a variety of designs and are a cost-effective medium-term solution available in a large variety of shapes, sizes, and colors.
If you need a rugged planter to which you can attach accessories, then DeepStream’s own wood and recycled plastic lumber planters, created using the principles of sustainable design, may be a better solution than fiberglass planters.
More durable than other planters, but more limited in form, DeepStream’s commercial wood and aluminum planters deliver excellent value for money. With a Lifetime Structural Warranty, they reduce the overall effort and time that goes into bringing vibrant gardens to barren urban spaces in need of their beneficial cooling and air quality enhancing properties.
However, if you need more options in terms of form and style, three of the best alternatives to wooden garden planters are Fiberglass-reinforced Plastic (FRP), Glass-fiber-reinforced Concrete (GFRC), and Aluminum. It is important to understand that products manufactured with these materials run the scale from virtually worthless to the quality that Landscape Architects specify for signature projects.
There are a lot of considerations that go into choosing the right planter for a particular location including: form, root ball heating, and drainage, as well as the inherent limitations of materials and construction methods. You will find a detailed discussion of the issues with a lot of supporting pictures in my earlier blog entry, Planter Selection, so I’ll not repeat them here.
Fiberglass is an excellent lightweight material with which to create interesting modern planter forms and surfaces such as an outer gelcoat infused with metal, which oxidizes over time, a favorite of mine for its understated elegance. You will find a myriad of forms and sizes available on the DeepStream website, and while there are four metal finishes, my favorites are the copper and bronze.
Tournesol planters distributed by DeepStream are made with expensive polyester-based fiberglass strands as used in yacht construction, but it is chopped and sprayed, not laid up in biaxial mats, where the hull has constant exposure to water. This Fiberglass-reinforced Plastic (FRP) is sprayed into molds that have been prepared with gel-coat.
FRP is a lightweight, strong material made up of layers of polyester resin alternated with glass strand. The strength and durability of fiberglass depend upon the number of layers of resin and glass. To ensure the longevity of the planters, they are waterproofed with an additional layer of black gelcoat resin inside.
The large rectangular commercial-grade movable Fiberglass Planters in the photos below were supplied by DeepStream to the restaurant operator at New York’s Rockefeller Center. The planters rest on caster bases so that they may be rearranged to meet the operator‘s changing needs. At summer’s end, they are simply rolled away to storage to reopen the famous ice skating rink during the winter season.
Fiberglass planters are lightweight and strong for their weight and thickness, but they are rigid and brittle. While the fiberglass planters we sell have a 3-year warranty, a 1-year warranty is more common.
Although the planters shown in the pictures below ARE NOT the fiberglass planters we sell, you need to be aware that all fiberglass planters are brittle, unlike wood or aluminum. Looking closely, you can see the vertical cracks that are developing over the edge in the center of this planter’s stiffening flange as the roots push out. Once the flange goes it leads to a catastrophic splitting failure, as the flange is responsible for structural strength.
When roots push out against the side walls, first the flange cracks, then the long side panels spit vertically. While it is possible to prevent this in construction, it is costly. Currently most of these “me too” planter manufacturers are competing on price, with Indian and Chinese imports skimping on materials.
Most fiberglass planters are light at the expense of strength and may not be durable enough for certain location. This is why even the best manufacturers provide just a 3-year warranty.
In addition, fiberglass planters are almost all single-walled and prone to solar gain. White or light-colored finishes would be better in sunny locations. They do not have drainage control, nor do they hide drip irrigation lines.
The large expensive planters shown below are installed in Miami’s downtown area and, while shaded by buildings, they are not really rugged enough for the streetscapes in which they are installed, nor do they have much surface area. Believe it or not, these planters are just 1/8″ thick painted skins of chopped fiberglass sprayed into a mold.
Selecting planter liners with the features your project requires will save you time, money, and effort.
Major considerations when selecting planter liners are the shape of the planter, the material the liner is constructed with, the location of drain(s), and size relative to your landscaping requirements.
Selecting planter liners with a shape tapering to a smaller base makes for repotting slip-out easy and if they stack then you save money shipping.
Rugged commercial grade 3/16″ walls from UV-stable, 100% pre-consumer recycled low-density polyethylene, or polypropylene are both flexible and food-safe, they will last decades in the sun and unburden landfills as they are recyclable materials.
Side wall, not bottom drain, aids drainage. Is the drain threaded for proper drainage systems accessories if required by your locations.
There is a water reservoir below the drain for the tap root while providing a place for “fines” or clay to settle to prevent drain blockage.
Liner depth is determined by the requirement of the plants you have selected.
An important consideration to successful landscaping in planters is starting with the right soil mixture and drainage for your plants.
You want your container to drain well while retaining moisture but not hold water. Do not use “dirt” or any material with clay which will block drains. Perlite is a good light weight additive if your trying to improve quick drainage, Vermiculite if your trying to retain moisture. Very course sand, like commercially available “paver base” if you need weight to prevent toppling in high winds but not fine “beach” or “mortar” sand as they will immediately block your drains. Remember many plants have specific soil PH needs.
Geo-textile fabric and drain board to provide filtration and space over drain.
BioBarrier (TM) with a plastic-embedded non-systemic herbicide, with a lower toxicity than table salt or aspirin, that creates a 2″ thick root deflection zone around the drainage material by preventing root cell tip division. The product, guaranteed effective for 15 years, has been used as a weed control system for more than 35 years in agriculture to prevent weed growth between row crops. Drainage pads are placed over the drain hole.
To prevent clogging you need to slow the water so that the fines in the planting medium settle to the bottom and not onto the filter medium. When selecting planter liners pick one with sidewall drainage, not on the bottom. This is an integral part of the drainage system as it allows the “fines” to settle to the bottom below the sidewall drain. Traditional pea gravel is too large and the water will flow rapidly to the drain and clog it with fines. Fine sand will flow too slow and form an impenetrable layer clogging with fines. There is no need to put rocks or gravel in the bottom of a plastic pot, it only raises the water table.
It is best to use a 2 to 4 inch thick covering of very clean, very coarse sand of between 1 and 2 mm particle size mounded over the drain filter. For reference, the wire of a medium paper clip is 1 mm. We have had good results here in Florida with “rubber mulch”, but then we can get 6″ of rain in one day.
“Paver Base” is an acceptable readily available alternative from most large home improvement stores and will work in our planter liners with a side drain as the well below it provides a place for fines to settle. Rubber mulch may also work for you.
Direct Links to helpful tips and information on planter liners, irrigation, and drainage for planters and container gardening: