How to build your own low-waste seed trays with cardboard and still get strong healthy seedlings

How to build your own low-waste seed trays with cardboard and still get strong healthy seedlings

Eleanor Ashford
There’s a particular kind of contentment that only a gardener knows, the quiet thrill of nurturing life from the tiniest seeds to the most majestic blooms. It is here, amidst the pots, earth, and open sky, that our hands truly commune with nature. With sustainability in mind, I've been exploring low-waste alternatives to reduce my plastic footprint, and I find myself irresistibly charmed by the art of crafting seed trays out of commonplace cardboard.

Our modern-day relationship with gardening often feels like a delicate dance between the past and the future. We draw from traditions yet reach for innovation, blending these influences into a sustainable gardening practice. Cardboard seed trays offer an elegant solution, allowing us to harmonise these sensibilities. And so, I invite you on this journey of creativity and resourcefulness.

Choosing Your Cardboard

It all begins with selecting the right cardboard. This may sound a touch mundane, but believe me, it is the first delightful step in this eco-friendly adventure. The world is replete with options, from cereal boxes to toilet roll cores, each offering its unique texture and sturdiness. Embrace the charm of reusing what would otherwise clutter waste streams, providing yet another life for these humble materials.

Corrugated cardboard is especially useful for its strength and durability, but thinner options can work splendidly for smaller seedlings. Avoid overly glossy, ink-heavy boxes; not only are they less biodegradable, but they might harbour chemical residues. A simple soak in water will tell you if the carton disintegrates too easily for use.

Transforming Cardboard into Seed Trays

Armed with scissors, a ruler, and a modicum of patience, we can turn these sheets of paper into functional seed trays. Visualise a paper origami, there’s beauty in folding and forming something new. Begin by cutting your cardboard into long strips which bend willingly into squares or rectangles. Aim for dimensions suitable to the seedlings you plan to nurture; typically, a size of about 5 cm high, 7-8 cm wide works well. This will give the roots ample room while being a manageable size.

To assemble, simply fold up the sides and secure them with a spot of tape or stapling, mindful of using something recyclable. Alternatively, paper-based glues are marvellous for a fully biodegradable tray. For row trays, connect several boxes side by side, taping them at the seams with brown paper tape. This approach frees us from the fear of plastic contamination, for soon enough all will join the good earth.

Soil and Seed, Potting Mixes Worth Your While

The anticipation of sowing seeds into your carefully fashioned creations is where the magic lies. Sifted compost, fragrant and crumbly, serves as the nurturing blanket for your seeds. It’s worth combining with a smattering of horticultural grit or sand for drainage, especially if you’re planting more moisture-sensitive specimens. Choosing reputable, peat-free compost makes all the difference, we owe it to our bogs, those ancient cradles of biodiversity, to opt for more sustainable alternatives.

As you press the seeds into their newfound homes, respect their spacing requirements. Tempting as it is to cluster them like a crowd of merry shoppers, remember: adequate room begets vigorous growth.

Tending to Your Seedlings

Now for the gentle art of nurturing seedlings. These delicate green entities crave consistency and attention akin to a classic British garden, time-intensely, but always worth it. Water them judiciously, aiming for the sweet spot of moisture without waterlogging. Cardboard's porous nature assists admirably in this task, allowing excess water to seep away while sipping just enough to keep the soil damp.

Provide your seedlings with ample light, either from a sunny window ledge or beneath soft grow lights. It's akin to inviting heavy-headed peonies to dance under moonlit skies, a nurturing spectacle that fosters vitality and hope.

Watch for any signs of legginess or nutrient deficiencies, tweaking conditions as needed. A weak solution of seaweed fertiliser can provide the requisite sustenance without introducing unnecessary chemicals into your nascent ecosystem.

Transplanting, A New Chapter

The crescendo of this cardboard orchestra arrives when your petite wonders outgrow their initial abode, begging for more ample quarters. Delicately slice the bottom of each tray or unknit the edges. If the cardboard has begun decomposing, even better, roots can break free seamlessly into the wider expanse. Gently settle them atop prepared beds or into larger pots, using every encouragement to coax them into their new stage.

Be sure to recycle or compost any remaining cardboard. With all attendants happy and healthy in their new lodgings, you’ve not just grown seedlings but, in every sense, a gardener more mindful and respectful of the natural cycle.

Reflections on Sustainable Gardening

The elegance of homemade cardboard seed trays extends beyond horticultural success; it speaks to an intentional living married to tradition. With so many voices calling us to urgent environmental action, these small, conscious steps affirm our commitment to preserving our planet. No effort is squandered when fostering nature’s menagerie.

Remember, gardening is not about instant gratification or austere minimalism. Indeed, our gardens celebrate diversity and resilience, creativity, and sustainability. As we continue to plant and prune, arrange and compost, we carry with us lifetimes of wisdom alongside a steadfast resolve to protect the earth's bounty.

In weaving your own cardboard seed trays into your gardening routine, you join a lineage of resourceful souls who find simplicity enthralling and recognise the beauty of a sustainable promise. With each season, we grow not only plants but a deeper connection to our wild, wonderful world, a tapestry of life rich in purpose and potential.
Back to blog