7 Best Plastic Twine For Greenhouse Tomatoes That Prevent Stem Breakage
Strong plastic twine is vital for supporting greenhouse tomatoes. Our guide reviews 7 top options to prevent stem breakage and ensure a healthy harvest.
There’s nothing more heartbreaking than walking into your greenhouse to find a beautiful, fruit-laden tomato vine snapped in half on the floor. All that work—the watering, the feeding, the pruning—is lost in an instant because of a simple support failure. Choosing the right twine isn’t just a minor detail; it’s the critical link that protects your harvest from the weight of its own success.
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Choosing the Right Twine for Heavy Tomato Yields
The biggest mistake growers make is grabbing any old string they have lying around. Jute or cotton twine might seem natural and strong, but it’s a trap. In the high humidity of a greenhouse, that organic fiber will absorb moisture, stretch, and eventually rot, failing right when your plants are at their heaviest.
You need to think about three things: strength, stability, and texture. Tensile strength is obvious—it has to hold the weight of a dozen beefsteak tomatoes. Stability is less obvious but just as crucial; you want a twine that won’t stretch under load or degrade from UV exposure halfway through the season.
Finally, consider the texture. A twine that’s too rough can chafe and cut into the main stem, creating an entry point for disease. One that’s too slick and waxy won’t grip tomato clips properly. The ideal choice is a strong, UV-stable polypropylene twine that’s soft enough to be gentle on the plant.
HORTOMALLAS Twine for Commercial-Grade Support
This 600-foot jute twine is perfect for crafting, gardening, and gift wrapping. Made from natural jute fibers, it's strong, biodegradable, and easy to use for various DIY projects.
When you want to eliminate twine failure as a variable, you look at what the pros use. HORTOMALLAS is a name synonymous with commercial horticulture for a reason. Their twine is engineered for one purpose: to reliably support heavy cropping plants through an entire season without stretching or breaking.
This isn’t your average hardware store polypropylene. It’s manufactured for high tensile strength and consistency, meaning you won’t find weak spots in the roll. It’s also treated to resist breakdown from the intense UV light inside a greenhouse, which is what makes other plastics brittle over time.
The main consideration for a hobby farmer is roll size. HORTOMALLAS is typically sold in large spools of 6,000 feet or more, which could last a small greenhouse operator a decade. If you have the space to store it and see the upfront cost as a long-term investment, it provides unmatched peace of mind for those prized heirloom varieties.
Grower’s Solution Twine for Heavy Fruiting
Grower’s Solution strikes a perfect balance for the serious hobbyist. They offer professional-grade quality but in packaging and quantities that make sense for someone who isn’t managing acres of greenhouses. This is the go-to when you want reliability without committing to a lifetime supply.
Their polypropylene twine is specifically designed for trellising and supporting heavy-fruiting plants like indeterminate tomatoes. It has excellent knot strength and works perfectly with standard tools like tomato clips and rollerhooks. The texture is soft enough that it won’t damage the vine as it grows and thickens.
Think of this as the purpose-built solution. While other twines might work, this one is made for the job. There’s no guesswork about its UV resistance or its breaking strength, which is usually rated to handle well over 75 pounds of pressure. It’s a dependable workhorse for any high-yield tomato crop.
SunSelector PolyTwine: Top UV-Resistant Choice
In a greenhouse, the sun is both your best friend and your worst enemy. The same UV rays that power photosynthesis are relentlessly breaking down plastics. SunSelector PolyTwine is engineered specifically to win this battle, making it a top choice for growers in high-sun environments.
Untreated twine can become brittle and snap with a simple nudge by mid-August, especially in southern climates or under clear poly roofing. SunSelector incorporates powerful UV inhibitors into its polypropylene formula. This ensures the twine maintains its strength and flexibility from transplanting day all the way through the final harvest.
This twine is often white or a very light color, which helps reflect some of the intense solar radiation rather than absorbing it. If you’ve ever had a support line mysteriously fail on a hot, sunny afternoon, switching to a dedicated UV-resistant product like this is the solution. It prevents those catastrophic, mid-season collapses.
Tytan Baler Twine: Maximum Strength Option
Sometimes, you just need brute force. Tytan Baler Twine isn’t marketed for greenhouses—it’s designed to hold together 1,000-pound hay bales. That extreme tensile strength makes it a compelling, if unconventional, option for supporting the most massive tomato varieties.
If you’re growing giant heirlooms that can top two pounds per fruit, the cumulative weight on a single vine can be immense. Standard greenhouse twine is strong, but baler twine is on another level, often rated for several hundred pounds of breaking strength. If you’ve had other twines snap under sheer weight, this is your answer.
There are tradeoffs, of course. Baler twine is often thicker and can have a rougher texture, so you need to be careful not to girdle the plant stem. It’s also not always rated for UV stability, as hay bales aren’t typically left in the sun for four months straight. However, if you already have a roll on the farm, it’s a perfectly functional and incredibly strong choice for a single season.
FarmTek Dura-Twine for Season-Long Durability
FarmTek is a trusted name in the small farm and homesteading community, and their Dura-Twine is a reflection of that. It’s a no-nonsense, reliable product designed to meet the expectations of growers who can’t afford equipment failure. This is the definition of a safe, dependable choice.
The "Dura-Twine" name says it all. It’s built for durability, with a strong focus on resisting rot, moisture, and UV degradation throughout a long growing season. It has minimal stretch, which is critical for maintaining proper plant tension in a lower-and-lean trellising system.
This twine is designed to integrate seamlessly into a typical greenhouse setup. It fits standard rollerhooks and is the right thickness and texture for modern tomato clips. For the grower who wants to buy a product they know will work without any fuss or special considerations, FarmTek Dura-Twine is a solid industry standard.
Uline Polypropylene Twine for Bulk Savings
For the hobby farmer with a large greenhouse or many other uses for twine, buying in bulk is the most economical path. Uline, a major supplier of shipping and industrial products, offers polypropylene twine at a price per foot that horticultural suppliers can rarely match. This is the budget-conscious choice.
The key is to pay close attention to the specifications. You are buying a general-purpose product, not a specialized horticultural one. Look for the tensile strength rating (often listed as "knot strength") and check whether it has any mention of UV resistance. For greenhouse use, you absolutely need both.
This approach requires a bit more diligence from the buyer. You trade the convenience of a purpose-built product for significant cost savings. If you find a Uline twine with a 100+ lb tensile strength and some level of UV treatment, you can secure enough support line for many years at a fantastic price.
Gempler’s Greenhouse Twine: A Reliable Standard
Gempler’s is another long-standing supplier for growers, and their house-brand greenhouse twine is a testament to their understanding of a plant’s needs. This twine is often praised for being exceptionally soft and flexible, minimizing the risk of stem damage as the plant grows and sways.
While all polypropylene twine is strong, Gempler’s focuses on a product that is "plant-safe." It’s designed to grip clips securely without being abrasive on the vine’s epidermis. This focus on plant health makes it a favorite among meticulous gardeners who want to prevent any potential source of stress or injury to their crops.
Choosing Gempler’s is about trusting a brand that specializes in horticulture. They offer various strengths and sometimes even biodegradable options for those looking to reduce plastic use. It’s a premium, reliable choice for growers who see their support system as an integral part of plant care, not just a piece of hardware.
Ultimately, the best twine is the one that lets you sleep at night without worrying about the weight of your harvest. Whether you choose a commercial-grade option for massive heirlooms or a bulk product for a large-scale hobby setup, investing in strong, UV-stable plastic twine is the cheapest insurance you can buy for your tomatoes.
