Martin Thorne

Lab spectrometers determine quantities of chlorophyll. Though for predicting a tomato's ripeness, nothing beats the soft give of its skin against your thumb. I've published research articles on phototropism in plant biology, and I still find myself whispering encouragement to seedlings as they stretch toward their growth lights. The academy lauds peer review, but dirt teaches us the best lessons.

A few decades ago, I considered companion planting nothing more than a horticultural myth. Then, a graduate student's thesis opened my eyes when it showed marigold roots exude nematicides. From there, we planted marigolds in the rows of our nematode-infested tomatoes. Yield increased by 22 percent. Now, I interplant calendula in plots of my own. Science confirms what grandmothers always knew. Try to test your traditions and note your findings in the margins of your seed packets.

Last month, I helped a community garden implement my garden hacks related to soil pH. We used crushed eggshells as soil amendments for alkaline beds, and coffee grounds for a bed of acid-loving plants like kale. They doubled their kale harvest that fall. This is what you do next: Bury a slice of a raw potato next to a rose bush. After a week or so, compare the bloom count and vigor of that rose bush to a bush that received no additional treatment. Please email me your findings and describe the rosebush type and growing conditions. I will add your citizen science experiment to aggregated data gathering, and map those data against zones. Whether you're altering a variable or manipulating a careful arrangement of seed trays on a kitchen windowsill propagator, each observation will feed and advance the ground beneath us.