Experimenting With Onions 2025

Something I love about gardening is that every season brings new challenges. Even crops that you’ve been successful with for years can offer areas of growth. This year, I have decided to really focus on my onions. At this point, I consistently produce enough onions for a year and am able to store them over winter. The problem I have encountered is that my onions have always been much smaller than they should be. I decided to try to solve that problem this year. I did a bit of research and found a few techniques that I thought I would try to improve my onion growth. My strategies are outlined below and I’ll bring updates on their progress throughout the season!

Though I ultimately hope to have a self-perpetuating garden, I still plant my onions using sets. My first step was to dig a shallow trench and remove the dirt from the previous year. I placed this dirt into my compost pile to be recycled and enhanced for the next year.

After the trench was dug, I decided to add my fertilizer to the bottom of the trench. I saw a video earlier this year that placing fertilizer in the bottom of the onion trench will help the bulbs grow larger. The onion bulbs are the food/nutrient storage system for the plant, so I figured this strategy was worth a try. The fertilizer that I put in the trench was a mix of used coffee grounds that have been saved throughout the year as well as ash from my wood stove. I was initially concerned about the pH of the soil, but I realized that coffee is acidic (low pH) and ash is basic (high pH) and concluded that, when combined, they’ll help keep the soil pH fairly balanced.

After the fertilizer was in, I brought soil in from my compost pile. This soil is a combination of sandy dirt, old leaves, kitchen scraps, coffee grounds, and bedding from my goats and rabbits. I am hoping these added nutrients will also ensure bountiful onion growth for the year. Once the trench was filled with fresh soil, I planted the onion sets. I gave each onion around 4-5 inches of spacing in all directions and pushed them into the dirt about an inch deep. Lastly, I covered the soil and the onions with a thin layer of leaves from last fall. My hope is that the leaves will act as mulch to keep the bulbs warm during this first part of spring and damp during the hot months of summer. After the onions had been covered, I watered the bed thoroughly with my garden hose. I haven’t connected my irrigation system yet for fear of a few final freezes this spring.

Now the waiting game begins! I’ll update the blog as the year goes on. Hopefully, we learn something!