How SunFlex Works For Your Seedlings
The SunFlex System combines superior greenhouse technology with trunk building support in a one-of-a-kind seedling establishment method that works the first time, every time. Providing seedling and tree protection from the time of planting, nurturing rapid & sustained growth, and building a solid foundation for long-term success is a lot to ask but SunFlex alone gets this job done. Let's dig deeper to see how SunFlex succeeds where you need it most....in the field.

It All Starts With The Sun...
The SunFlex name says it best because, like a greenhouse, it all starts with the SUN! Everything we build into SunFlex respects what is most important to grow your plants healthy, safe and fast.
The image to the right is a basic overview of photosynthesis as it relates to SunFlex. The critical inputs are sunlight, CO2 and water and each impacts how and why SunFlex is the only true "Green-House Grow Tube" for trees and the best choice for your seedlings.

SunFlex Grows Your Seedlings Fast & Healthy.....Naturally!
The image to the left illustrates how SunFlex works in your field to deliver unmatched growth in a safe, seedling-friendly, grow tube design.
Proprietary greenhouse technology filters and diffuses sunlight for easier use by leaf photo-receptors to achieve efficient & superior plant growth. Managing sunlight in this way also helps keep temperatures from becoming too hot inside the tube.
Plantra's exclusive Cross-Flow™ venting achieves two important goals. First, it boosts CO2 recharge for optimal growth. CO2 is easily limited inside unvented, traditional or older style "tree tubes" and "tree-shelters." Limiting CO2 causes a bottle-neck for growth. Cross-Flow venting also encourages cold air movement inside the tube during the fall to encourage proper dormancy. Unvented tubes can inhibit proper dormancy and cause what is commonly referred to as winter "die-back."

SunFlex Shock Prevention Zone (right) blocks 100% of drying winds that can kill seedlings before they ever get going.
SunFlex's twin-wall construction and proprietary pigment system also filters and diffuses sunlight to reduce leaf stress and increase photosynthetic efficiency. Diffused light through the tube walls blankets the leaf at all angles. Studies show diffuse light increases photosynthesis by 20% over direct beam light.
The reddish tube walls stimulate the plant's phytochrome pigments to trigger sun-adapted shoot growth with strong roots. Together, these greenhouse benefits help seedlings survive the transition from the nursery to full establishment in the field.

SunFlex Acclimation Zone (left) gently prepares the plant for conditions outside the tube with a combination of dappled shade, limited direct beam sunlight and controlled air movement to stimulate leaf and stem thickening.
Plantra's exclusive Cross-Flow™ ventilation increases growth by replenishing vital CO2 consumed in photosynthesis and prevents excess moisture build-up to avoid fungal development and encourage proper dormancy in the fall.

SunFlex Transition Zone (right) helps accomplish two things. First, your tree's natural phototropism responds to the combination of our proprietary color pigments in the tube side walls and to blue light streaming in from the tube top. This response channels stem growth up and out of the tube while suppressing large, undesirable lateral branches down inside the tube.
Second, this zone, provides safe trunk support your sapling needs to grow into a straight and strong tree. The key to growing the strongest trunks begins with SunFlex Trunk-Builder support stakes which flex in the wind naturally. This movement triggers thigmomorphogenesis responses that promote stem thickening and stronger root growth. The result is stronger, wind-firm stems and trunks in record time.
The engineering and benefits described above make SunFlex Grow Tubes the "grower's greenhouse choice" when it comes to rapid seedling establishment, the first time, every time. To optimize the SunFlex advantage that begins in the grow tube you'll need Trunk Builder support stakes to finish the job.
Trunk Builder Stakes Are The Backbone Of The SunFlex System
We've said it before but it's worth repeating......."Your grow tube installation or tree training project is only as good as the stake you choose for the job!" That's why we engineered Trunk Builder stakes to stand-up straight on the toughest sites from wild lands and commercial ag fields to high traffic boulevards and serious home gardens.
Trunk Builder is a game changer when it comes to growing stronger, healthier tree stems with superior strength all with a stake that lasts until your trees are on their own. But Trunk Builder doesn't stop there. It's rugged construction is super easy to use whether your planting crews are professionals or weekend warriors. Engineered strong but lightweight and with the only ground line offered for grow tube stakes, Trunk Builder slashes time and labor costs so you get the job done fast, right and within budget. And when your trees are on their own Trunk Builder can be used again and again.
Still not convinced? Let's "dig deeper" to see why SunFlex Trunk Builder stands above the rest.
Rule #1 - Stake Flexibility + Memory = Stronger stems and trunks!
Plant biologists have long understood the role that stem movement contributes to strength and stem caliper. Stem movement caused by mechanical influences from wind or pushing and bumping by animals or people triggers chemical responses in the plant including "thigmomorphogenesis." Thigmomorphogenesis (Thigma meaning to "touch") alters growth patterns to respond to wind and mechanical influences that cause the growing tree to move back and forth. The result is growth leading to stockier and stronger stems.
To get stockier, stronger and natural stem growth you need a support stake that moves with the tree. That's where Trunk Builder stands alone in a forest of rigid stakes made of wood, bamboo and metal that were once the only options to support grow tubes, tree tubes and tree-shelters. The image to the right illustrates how Trunk Builder "flexes" above ground to move with your trees as they grow and promote stronger stems....naturally! And unlike hollow plastic plumbing pipe which can bend and stay bent, Trunk Builder's fiber-reinforced design bends when the wind blows and snaps back straight when it stops.
Rule #2 - Rigid wood and bamboo stakes don't flex and don't last.
Wood and bamboo are strong building materials important to construction. However, when driven into the ground and subjected wind or soil moisture these stakes are poor choices to support grow tubes, tree tubes and tree shelters or to train trees with the strongest stems. It's no secret that these materials do not flex which, as we've discussed, inhibits optimal growth necessary for strong stems and trunks. What might not be known is how short-lived wood and bamboo are in the field. Natural materials like and bamboo degrade when exposed to rain, microbial activity, and temperatures conducive to freezing and cracking or conditions that promote decay and rot.
Many wood and bamboo materials have been used in the past with disappointing results. One of the most often used materials, because of its low cost, is Pine lath. Unfortunately lath stakes (often used by surveyors for temporary marking) are one of the poorest choices because it often rots in the first 12 months (see image below of rotted and broken lath stake). Even mighty oak stakes rot-off, break or warp (see image on to right) in the first several seasons often within just two years. And it's worse for bamboo. Even stout 1-inch diameter bamboo splinters when driven into the ground and often fails to last into the second season before rotting and breaking off. Considering grow tubes need to remain in place for 7 years (or even longer in many cases) wood or bamboo is clearly no match for job.

The image sequence below illustrates what can happen when wood and bamboo stakes are subjected to soil moisture, wind or contact by animals. Because wood and bamboo are rigid, two outcomes are the most common. The first, shown in the image on the left, is for the stake to "scallop" the soil below ground as the stake moves back and forth. This result is common with soft soils and often leads to the stake base creating a hole that grows. Over time, the displaced soil can no longer anchor the stake and eventually (often very quickly) the stake fails and the tube and tree often end up on the ground where the tree dies. In the second outcome, shown in image on right, the stake simply rots and snaps off completely causing the tube and the tree to end up on the ground.

Rigid Stake "Scalloping" In Soil Rigid Stake Breaking
Rule #3 - Engineering on purpose, for a purpose is the way to go!

If your trees are worth planting, they're worth Planting Like You Mean It and this means using tools designed to do the work. Say good-bye to materials that don't work or were never intended to be a part of your planting. SunFlex Trunk Builder is engineered and "purpose-built" for the job of supporting grow tubes and training tree trunks. Designed to be 110% the strength of 1/2 inch round fiberglass rod Trunk Builder is the new benchmark for field performance. Unlike Trunk Builder, rigid materials like wood, bamboo, metal rebar, t-posts and electrical conduit were designed for very different uses none of which involved supporting grow tubes and growing healthy, stouter stems and trunks.....naturally. The same goes for flimsy, hollow plastic tubes and PVC pipe. These plastic materials were designed for much different uses and while they can bend, they have little or no "flex memory" and can stay bent.

The backbone of SunFlex Trunk Builder was born in geometry and reinforced with super strong e-glass fibers. The 3-sided delta profile (see image above and on left) was engineered to deliver tremendous strength to weight ratio with rapid "flex-memory" that bends with the wind and returns to straight when the wind stops. Trunk Builder won't rot and is virtually unbreakable. Tired of of everything from wind to animals snapping off your oak and bamboo stakes at ground level? So were we. That's why we engineered Trunk Builder tough enough to stand up to the toughest winds to even to ole' mossy-back when fall buck antler rub season is in full swing. And unlike pencil rod or flimsy hollow plastic stakes which can bend under a load and stay bent, Trunk Builder returns upright to keep growing your trees up straight and strong.
Rule #4 - Ease of use matters!
Grow tube stake installation should be fast, easy, and accurate. That's why we engineered Trunk Builder with grower in mind. Trunk Builder was designed with it's own stake driver to help the narrow profile slice through tough ground that can stop wood and hollow plastic stakes in their tracks. Whether you're planting 5 trees or 5,000, Trunk Builder stakes drive like a dream saving you time and money getting the stake into the ground fast. Trunk Builder is also matched to SunFlex Grow Tube heights and comes complete with the only ground line indicator on the market which means no more guessing about how deep to drive the stake (see image below).

As you can see, SunFlex is more than just a "tree tube" or "tree-shelter" with a stake. SunFlex is a "System" with state-of-the-art green-house grow tube technology with a trunk building backbone. Put SunFlex to work in your next seedling tree planting and get growing the way the pros do.