Many of my neighbors have asked me what my secret is for growing the six-foot-tall, four-foot wide tomato plants that have adorned my yard every summer since I moved into this house. My street's resident Chief Plant Lady (whose bed of stately irises yearly ignites the envy of every flower-growing soul in a three block radius) once haughtily accused me — in public, no less — of "Dousing them Juliets in syn-thetic fertilizer. Hmph."
I've always said there's no secret, really: I choose healthy seedlings; I plant my tomatoes in the sunniest spot in my yard (which, fortuitously, happens to also be the place where a French drain that carries rain water away from my foundation empties); I plant in a raised bed, which improves drainage; I use sturdy tomato cages to prevent wind damage, and I check my plants frequently for insect pests, which I remove by hand.
That's it, really. That's the basis of my Secret Formula for Growing Really Huge Tomato Plants That Make Mild-Mannered Neighborhood Plant Ladies Snark at Me in Public.
But, there is one special ingredient I often neglect to mention that may by giving me a bit of an edge over my less lucky neighbors when it comes to the successful supersizing of Solanum lycopersicum .
What is this secret, special ingredient that I have begun to suspect may well hold the key to my unprecedented tomato success?
Every spring, when I prepare my garden bed, after adding whatever organic soil amendments I think I may need (like compost, for example), I cover each of my beds entirely with burlap. On top of the burlap, I generally add a one inch layer of hardwood mulch.
I tried this the first year I built my garden beds at this house, almost entirely on a whim. I was looking for something to help me suppress weeds in my vegetable garden, because I'm lazy weeder. But I didn't like the idea of using black fabric weed blocker, as this is generally made out of plastic. I saw some rolls of burlap for sale one day in the garden section of my hardware store, and thought, "Hey! That's not plastic!" And I bought it.
Was it a coincidence that that summer I grew the largest tomato plant I had ever personally seen?
Burlap is made of jute, which is a natural vegetable fiber, and therefore totally biodegradable. This makes it great as an all-natural weed suppressant.
But another benefit to covering my garden with burlap, as far as tomatoes are concerned, is that the thick fabric fibers actually insulate the soil, warming it to a higher temperature. Tomato plants prefer warm soil, and while many gardeners recommend pre-warming your garden beds with black plastic to create ideal conditions for tomatoes (because the color black absorbs sunlight so well), I've found that a layer of burlap topped with wood mulch works rather well to keep the soil warm despite its lighter color.
Also, the jute fiber used for making burlap cloth is acidic, with a pH around 6 or so (7 is neutral). And tomato plants prefer acidic soil. I'm no chemist, so what I'm about to say is pure speculation. But I think that as burlap breaks down, it probably dumps a nice dose of natural acids into the soil. The burlap covering I lay out each spring biodegrades quickly enough that it's almost completely invisible by September. So I leave it in the soil, where I assume nutrients from decomposing jute fibers will continue to do my tomato plants good the following spring.
So, if you're looking for the secret to tomato success, I'd recommend giving burlap a try this year.
If nothing else, it will cut down on your weeds.