Planter Drainage: modern solutions

Planter Drainage

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.

DeepStream rugged waterproof recycled LLDPE food safe plastic liners with advanced drainage and easy to replant tapered design.
DeepStream rugged waterproof recycled LLDPE food safe plastic liners with advanced drainage and easy to replant tapered design that is economical to ship.

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.

DeepStream Wood Garden Planter with a Trellis acting as privacy screen wall has a tapered waterproof inner liner with advanced drainage that allow the plant to flourish and flower.
DeepStream Wood Garden Planter with a Trellis acting as privacy screen wall has a tapered waterproof inner liner with advanced drainage that allow the plant to flourish and flower. The liner provides separation between the wood and the soil, not only extending the life of the planter by decades, it also keeps the the roots from steaming by the “solar gain” which heats the roots ball.

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.

DeepStream rugged waterproof planter liners with advanced drainage
DeepStream rugged waterproof planter liners with advanced drainage and threaded ports are made with 100% recycled food safe LLDPE plastic. Their tapered shape aids replanting and economical shipping.

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. 

A large installation of Custom Welded Waterproof Planter Liners on a roof top are compartmentalized to isolate drainage problems. Drip irrigation lines are inserted through the top of liner walls below soil level.
A large installation of Custom Welded Waterproof Planter Liners on a roof top are compartmentalized to isolate drainage problems. Drip irrigation lines are inserted through the top of liner walls below soil level.

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

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.

click for more info on waterproof planter liners within a facade
A waterproof planter liner with advanced drainage within a wood planter box

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.

Drain Location

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.

Click to DeepStream's website for detailed information on planter liners, drainage solutions and drain pads
Commercial recycled plastic liners, drainage board, weed block, Bio-Barrier
DeepStream Designs commercial grade recycled plastic liners with drain well and threaded outlet, solve planter drainage problems before they start
Solve planter drainage problems before they start. DeepStream Designs commercial grade recycled plastic liners with drain well and threaded 3/4″ NPT outlet for adding hose fitting if required.

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 Perliete 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.

While not ideal, paver base is available nationwide at a large home store and is a reasonable planter drainage material to slow the water flow given that DeepStream Designs planter liners have a sump below the drain to catch the "fines"
While not ideal, paver base is available nationwide at a large home store and is a reasonable planter drainage material to slow the water flow given that DeepStream Designs planter liners have a sump below the drain to catch the “fines”

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.

click picture for more information on advanced planter drainage options
3 part planter liner drain pad with drain board, geo fabric, and Bio-Barrier.

Recycled Plastic Lumber Planter

Recycled Plastic Lumber Planters: Helping the world’s Rainforests.

In 2009, DeepStream started offering low maintenance Recycled Plastic Lumber Planters (RPL) as an alternative to tropical hardwood planters.

DeepStream's Large square Commercial Wood Planters for Trees use maintenance free recycled plastic lumber inside thier aluminum frames: click for more info
DeepStream’s Large square Commercial Planters made with recycled plastic lumber are strong enough to hold trees thanks to their hidden structural aluminum frames and plastic planter liners.

Over the past 11 years more and more DeepStream customers have been choosing recycled plastic lumber planters over tropical hardwoods harvested from rainforests.  By 2017, RPL was specified more often than natural wood thanks to the concern of our customers and their commitment to the environment.

High profile green roof projects such as Boston’s Fenway Park have chosen DeepStream’s planters as the perfect combination of sustainable design, recycled, and recyclable content providing both the lowest total impact on the environment and lowest cost of ownership over time and low maintenance.

Graph shows Recycled Plastic Lumber is increasing in popularity
Sales of DeepStream Designs’ Recycled Plastic Lumber products exceeded those of Tropical Hardwood by 2017

Recycled Plastic Lumber Planters reduce maintenance costs while enhancing your properties and brands through the timeless beauty and environmental statement that DeepStream Recycled Plastic Lumber Planters, trash and recycling bins make with your customers.

Click to DeepStream's solutions website to see more about commercial quality recycled plastic lumber planters
Recycled Plastic Lumber Planters and combination Commercial Trash and Recycling Receptacle

Like many successful companies, DeepStream was created in a response to a need.  While building a condominium project and reviewing the “universe” of garden planters, we found that what we wanted was not available elsewhere.

Wood planters were all carpenter-built with wood-on-wood construction, and as I’ve detailed in my Planter Selection Blog and, like many other construction techniques and materials, they just don’t last and waste a precious resource and your money. They give your business a bad image of low quality and lack of care, it’s better not to use any at all.

Rickety carpenter built wood planter
Rickety planter with carpenter built techniques soon fall apart as the planter goes to wet and dry cycles

The valuable wood harvested from the world’s rapidly diminishing rainforests is wasted, as the planters tear themselves apart and are thrown away in a few years (typically 3-4 years here in Miami).

Ugly carpenter built wood planter in front of a restaurant
Wood Planters using carpenter built techniques soon fall apart

If your project absolutely must use tropical hardwood, then specify DeepStream’s Mariner Planter System as it is engineered with the principles of Sustainable Design to use, or even reuse, hardwood or recycled plastic lumber in a design that honors the wood, allowing construction that extends wood life by decades.

click tp DeepStream's solutions website for more information on wood vs recycled plastic lumber planters
While not as environmentally friendly as recycled plastic lumber planters DeepStream Commercial Wood Planters will last for decades and create a bright natural sidewalk café while absorbing carbon, giving off oxygen, cooling the sidewalk, and creating business for the restaurant inside that might otherwise go unnoticed.

Harvesting tropical hardwood destroys important habitats around the world, even if “sustainably harvested,” as hardwood trees take 50 years or more to reach maturity.  A recent article in the New York Times put the percentage of tropical hardwood illegally harvested but sold with counterfeit documents at 50% for Brazil and 90% from Peru.

According to the Yale School of Forestry, while estimates vary, it is thought that between 30 and 50% of all certified Tropical Hardwood shipped into the United states has been “Greenwashed,” meaning that shipments have been provided with falsified and counterfeit documentation. In some countries like Peru, it’s estimated that 90% are illegally logged, devastating their Amazon watershed.

For more information click here: “ Greenwashed” Timber and FSC certification

Planters made with non-structural Recycled Plastic Lumber planks (RPL) inside DeepStream’s unique structural aluminum frame are a perfect choice for outdoor placement, while making a strong environmental statement.

5 standard wood grain recycled plastic lumber colors, click on picture for more information on recycled plastic lumber
5 standard wood grain recycled plastic lumber colors

Separate from the environmental concerns about using real tropical hardwoods, we highly recommend RPL Wood Planters, especially in locations such as shopping centers and parking lots, locations serving food and drinks which stain natural wood and make a mess, or anywhere sanitation and easy maintenance are a concern.  Because DeepStream’s trademark planter legs are anodized, not painted or powder coated, RPL planters can be pressure cleaned.

All natural tropical hardwood planters will turn a light gray color and show stains and mold spots if not treated with a waterproofing and UV protector several times a year. This treatment will make all wood darker over time.

Given the time and expense necessary to keep natural hardwood looking good, and the damage done to the rain forests to harvest it, versus the “set and forget” ease of using recycled plastic lumber, you should give serious thought to which you will select for your project. RPL comes with a 50-year manufacturer’s limited warranty, and DeepStream’s aluminum frame makes up for the fact that is non-structural.

DeepStream makes it easy and cost effective to go Green and stop contributing to climate change. By selecting recycled plastic lumber for your order, you will be preserving the world’s rainforests, the cooling lungs of the earth, while creating a sustainable market for post-consumer and post-industrial plastic waste.

4 premium wood grain recycled plastic lumber colors click for more information on recycled plastic lumber
4 premium wood grain recycled plastic lumber colors

Please discuss saving this diminishing resources for future generations with clients that specify tropical hardwoods. Our recycled plastic lumber requires no maintenance and lasts for decades without fading, saving your clients money while looking better over time than wood ever will.

If you do order natural hardwood, unlike carpenter-built planters, with DeepStream’s trademark anodized aluminum extrusions you know that your purchase will last for decades and not waste this precious resource.

Like offsetting your carbon footprint by buying carbon credits, another way to reduce this impact is to replant far more trees than are used in crafting our products. We do so in our customers names through Trees for the Future.

To date, June 2020, using proceeds from the sale of our products, DeepStream has planted more than 450,000 trees in our customers’ honor, reflecting DeepStream’s and our customers commitment to the environment we are leaving for future generations.

Before specifying tropical hardwood for your projects please look at the comprehensive worldwide overview of the problem created by using tropical information presented at this link:

Eliminate needless rainforest destruction by specifying DeepStream RPL planters and fixtures. The RPL DeepStream uses is backed by a 50-year limited warranty by its manufacturer.

Please call Sheila at DeepStream Designs 305 857-0466 to discuss your needs.

Spring Conditioning Planter Liners

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.

Tools Needed:

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.

Remove the bottom third of the root ball
Container Gardening Root Bound


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.

Planting Medium

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 .

container gardening repotting supplies
Container gardening requires a few simple repotting supplies. Don’t forget a tarp, broom, and dust pan.


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.

Automatic Drip Irrigation Manifold with Rain Sensor and 4 active zones.  Click pic to link to DripWorks website for more information.
Automatic Drip Irrigation Manifold with Rain Sensor and 4 active zones.

Repotting large plants:

With the Clusia the the steps are almost identical.

accessing the planter liner for spring conditioning
Lay the planter over on a padded surface and slide the liner out.
Remove roots growing over the sides of the planter liner if the liner won't slide out.
Remove roots growing over the sides of the planter liner if the liner won’t slide out.

The planter, planter liner, and planter drainage design all play an important role in planting maintenance and root trimming.

A bulging planter liner indicates it's time for root pruning
A bulging planter liner indicates it’s time for root pruning, it’s roots like these Calusia that have torn apart large pre-columbian temples in Central and South America.

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.

Paver Base or similar mediums slow water flow improving planter drainage
Paver Base, rubber mulch, or similar mediums slow water flow, improving planter drainage by allowing “fines” that can clog the drain to settled below the side drain.

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.

DeepStream Designs advanced 3-layer drain pad created with drain board, filter fabric, and Biobarrier
DeepStream Designs creates an advanced 3-layer drain pad out of drain board, filter fabric, and Biobarrier for you so all you have to do to maximize drainage is to place the pad over the DeepStream linner sidewall drain port and hold in place with the appropriate material to slow the flow of water to 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.

Planter Liner after root trimmed
Planter Liner after root trimmed

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.

Happy gardening! Tom