Planter Drainage: modern solutions

Planter Drainage starts with Planter Liners

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.

Solutions

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.

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.
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 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.

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.

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

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.

Recycled Plastic Lumber Planter

Long garden planters for restaurants in dark grey recycled plastic lumber creates a no-maintenance barrier wall to control access around a chic modern restaurant seating area. They may be sanitized with a pressure cleaner as there is no paint or powder coating to fail. Lifetime Structural Warranty.

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 12 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:

https://news.mongabay.com/2019/12/2019-the-year-rainforests-burned/

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.