We've talked about presprouting seeds in a previous entry. The main goal in presprouting is to get the seeds to germinate before they are deposited into the soil-free starting mix or are direct-seeded in the garden. The idea here is that environmental sprouting conditions are easier to replicate in a small incubation microclimate than in a 72-cell tray or garden soil. Presprouting is accomplished by rolling up seeds in damp paper towels and placing them in a plastic bag atop a heating mat. The seeds must be monitored on a daily basis for moisture levels; this periodic inspection also provides airflow, which is a crucial component to successful germination.
Pre-sprouting seems to work well for the small number of seeds we experimented with, but the task soon becomes onerous when applied to a larger number of seeds and varieties. For example, the daily unfurling of each roll of seeds becomes time consuming as the number of varieties increases. At first, we only dealt with 3 varieties of 3-5 seeds each. We then added a few more varieties after some initial success and then started to notice the added inconvenience of unwrapping and rewrapping a greater number of packages. Nevertheless, we did achieve some rapid germination with some of the seeds, noticeably with the purple coffee pepper. The earliest purple coffee sprout appeared within 5 days of starting the sprouts. The hot lemon peppers also performed well, with each of the 3 seeds sprouting on the tenth day. Ultimately, we have decided to reserve presprouting for small quantities or for direct-seeded plants that require warm soil temperature to germinate like melons, squash, and cucumber (i.e., the Cucurbitaceae family).
For the bulk of our pepper starts, we decided to use the same method that gave us great results last year. This is the 72-cell tray system with bottom capillary-action watering, a common seed-starting technique. The system works by placing the tray of seedlings on a water-absorbent mat which is kept damp by a reservoir beneath. This method provides an even supply of moisture to each cell and prevents overwatering. Our mats weren't absorbing enough water this year so we decided to stop using them and simply place the seedlings in a shallow supply of water. Mark then found out through his obsessive pursuit of gardening minutia that seedlings should not be placed in standing water for extended periods of time. These conditions lead to overly damp soil which can foster growth of the dreaded damping-off fungus. We are now keeping the cells watered by setting the tray in water for a half hour whenever the soil appears to have dried out, which is about every 48 hours.