Hello fellow readers,
“Be sure you tickle the roots,” I coach new gardeners after carefully removing a plant from its pot. Using my fingers or an edge of a trowel, I demonstrate how to loosen the roots to encourage them to spread. Sometimes a utility knife comes into play if a plant is root-bound; it’s like being crammed into a tight pair of jeans. It wasn’t until recently that I heard about rubbing while talking with a colleague from Hackettstown, NJ. Disclaimer -Richard didn’t describe it as such. We were chatting about planting protocols and whether to use Mycorrhizae, pronounced My-core-rye’s-eye. Okay, my phonetics may sound silly, but for sure, Mycorrhizae is the root of plant health. Richard suggests rubbing Mycorrhizal inoculant on the root balls of certain plants.
Mycorrhizae are fungi found naturally in soil, some scientists say for over a billion years. Because filaments called hyphae spread two hundred times farther than roots, they extract more water and nutrients, especially phosphorus, that transfers to roots which help plants increase their resistance to pests and disease. Plus helps them grow faster, produce more fruit, and overcome the impact of drought and salt stress. In turn, the plant provides the sugar the Mycorrhiza needs.
This friendship goes well beyond sharing nutrients. Mycorrhiza emits enzymes toxic to nasty organisms like nematodes. More fascinating is plants connected by Mycorrhiza share warning signals that help prepare them to defend themselves. Say aphids attack; the plant emits compounds that entice aphid predators. More than that, the fungi connected to adjacent vegetation produce the same compound, protecting their neighbors before they are attacked.
An overabundance of synthetic fertilizers, pesticides, and fungicides can kill Mycorrhizae, as will solarizing – a technique of covering the soil with plastic to kill weed seeds and insects. It flourishes best in soils rich in organic matter, such as compost which you should lay on top rather than digging in, as tilling and hoeing can kill the beneficial fungi.
They say ninety percent of all plants have this friendship, though there are different types of Mycorrhizae. Most have a blend of the kinds so that flora will find their match. Only when the soil is disturbed is adding inoculants a good idea.
Getting back to Richard’s recommendations versus my normal protocol of sprinkling a granular form of the fungi in the bottom of a properly dug hole, which is the root ball’s height and twice its width. Richard suggested rubbing the Mycorrhizal inoculant on the root ball itself. He shared photographs of a lush garden planted a year prior using liner plugs which are starter plants used by growers. “So not only do we need to tickle, we need to rub,” I chuckled. Tickle and rub. Soon planting may come with a PG rating. Garden dilemmas? AskMaryStone@gmail.com and your favorite Podcast App.
A side note about the temptation to fertilize when planting: fertilizers rich in nitrogen and phosphorus can negatively impact beneficial bacteria, mycorrhizal fungi, and protozoa, for example. It’s best to wait until your new plant becomes established before fertilizing with an organic product such as Pr-Gro or Plant-Tone.
Link to a related story – Talking to Trees on Arbor Day
Column updated 12/19/22