Whether you call them toilet paper rolls or loo rolls, in most households these small cardboard tubes multiply like rabbits. After reading about using toilet paper rolls to grow carrots, parsnips, and other vegetables, last year I tried it for myself. My maiden voyage with carrots was so successful that this year I’m starting some of my parsnips in toilet paper rolls, with a few refinements. Should I get a poor stand from direct sowing, I will have tube-grown plants to fill the gaps.
The method is far from new. Many years ago, English gardeners growing parsnips for competition discovered they could get an early start on the season with plants grown in paper tubes. The tubes protected the taproot from disturbance when the seedlings were set out, a critical detail because injury to the taproot can lead to forked, misshapen roots. More recently, some American gardeners found that the tubes protected transplanted carrots from cutworms, which sever plants at the soil line at night.
Setting Up For Seeding
To stage your first loo roll adventure, find a small square or rectangular container with good visibility, such as a clear plastic salad box. Write what you are planting on the dry toilet paper rolls, and place them in the container, allowing slight gaps between tubes to permit air circulation. Here you have the option of folding the tubes into squares, which are less likely to topple about, but do not offer the symmetrical growing conditions of a circular tube.
Fill the tubes halfway with seed starting mix or good quality potting soil, then tamp down to eliminate air pockets. Tamp again after filling the tubes to the top. Don’t worry about spilling a bit of soil around the base of the tubes, because it can help protect them from drying out. Moisten the soil until the outsides of the tubes appear damp, and proceed with planting.
I always prime my carrot and parsnip seeds by keeping them in damp paper towels for a few days, which really does speed germination. Whether you are growing carrots and parsnips in toilet paper rolls or the garden, at the very least soak the seeds in water overnight and dry them on paper towels before planting them. Plant three seeds per tube, and thin to the one closest to the middle.
Getting the Moisture Right
Once the seedlings are up and growing, they need to be checked daily to make sure they are neither too wet nor too dry. I suggest watering from the top, by dribbling water into the potting mix, and watching the colour of the cardboard to track the spread of the moisture through the tube. Should the potting mix dry out completely, speed rehydration by using a spray bottle to moisten the tubes from the outside. The appearance of visible mould means the tubes are too wet.
Carrots and parsnips send down taproots very quickly, so they should be set out as soon as the seedlings show a solid true leaf. Use a spatula to lift each plant, and set them in a well-worked bed. If set a little high, so the top of the tube extends above the soil, the dry cardboard collar can deter cutworms and perhaps easily dissuaded slugs.
I found that weeding between the tubes was a breeze, and here again, the toilet paper tubes may offer some benefit by minimising root disturbance caused by weeding. None of my carrots developed forks or kinks, and their colour was good, too. By harvest time, the buried sections of the toilet paper rolls had rotted completely, with only the top collar intact.
More Garden Uses for Toilet Rolls
Because of their depth, toilet paper rolls also are useful for starting snap beans, sweet corn, and other plants with deep tap roots, and they have been used with some success with sweet peas, which often sulk when their roots are disturbed. Later in summer, when leeks gain size, you can slit a toilet roll lengthwise and pop it around the leek’s neck to keep soil from accumulating there. When you run out of uses (but never loo rolls), simply add them to your compost when it’s going through a wet stage. The dry tubes will soak up excess moisture and provide food and habitat for composting critters.