Getting seeds started right

By Justin Husher

When spring can’t get here soon enough, it’s time to start getting your hands dirty starting some seeds!

Seed starting is fairly easy, given the right set-up, a bit of patience, and a bit of diligence. The wrong way to start seeds is in front of a window in northeast Ohio in March. The plant will respond to the low levels of light by becoming “leggy,” stretching in search of more light. Often these frail plants are so weak that they can’t even be handled, let alone transplanted.

So, what is needed to start seeds the right way?

  • Soil. The soil holds the moisture necessary to start the seeds. After sprouting, the soil is a place for the roots to grow and acts as a bank for nutrients. Store bought soil is most often peat moss based and amended with lime to buffer the pH and perlite for porosity. Every once in a while it comes with fertilizer. Try to avoid pre-fertilized soil – it may include too much fertilizer for young plants, burning or even killing them.
  • Containers with lids. The classic, industry-standard starting tray is 11 inches by 23 inches in size and made out of black plastic. These trays aren’t necessary, but they provide uniformity. Within that tray, you place a cell plug tray. Cell plugs come in varying hole sizes, ranging from 72 to 200 holes per cell plug tray. The cell plug tray actually holds the soil and the seed.

To accompany the trays, you will also want a clear plastic lid. These are formally called humidity domes, and as the name implies, they hold in humidity. You may also use a flat Chinese take-out container as a tray, coupled with yogurt containers as “cells,” and then topped with the take-out container lids as humidity domes. This is not very uniform, but will work in a pinch or for small-scale starting.

  • Heat mat. A heat mat is essential for starting seeds because most need warmth (around 80 degrees Fahrenheit) to sprout. Heat mats come in one, two, or four-tray sizes and sit below starting trays. When they are plugged in, they become moderately warm to the touch. Some homesteader types use them for making kombucha and kefir.
  • Light source. A standard four-foot-long, fluorescent light works well, especially when coupled with a four foot shelf and a four-tray sized heat mat. I am a big fan of using 150-watt equivalent compact fluorescent lights – they provide good light and can be turned on and off as needed. Growers have also had success with the new LED bulbs that emit blue and red light, but these bulbs can be more expensive. The metal halides and high pressure sodiums work better for established seedlings and are not recommended for new starts because they can physically burn the plants.
  • Hand sprayer. Seeds need moisture to sprout. When working with heat mats and lights, the soil has a tendency to become dry and a hand sprayer becomes a necessary tool for seed starting. To keep seeds hydrated, spray your trays several times a day, removing the lids and discarding the water that condenses there. This may seem counterintuitive, but there is a fine balance between wet enough and too wet.
  • A good location. Almost any place and any set-up can work given some creativity, but growers typically use 4 foot by 2 foot stainless steel shelves for seed starting. The shelves can hold a four-tray mat and a four-foot light and seem like they are made for seed starting.

Now that you have your materials, it’s just a matter of filling the plug trays with moistened soil, seeding the seeds, and putting the trays on top of heat mats with their humidity domes. Here’s where the patience comes into play.

Seeds germinate at different rates. Kales, arugula, and beets can sprout in as early as three days, while tomatoes take five to seven days. Peppers take a little while longer at seven to 10 days and ground cherries can take as long as 15 days. Stay diligent throughout your seeds’ germination period hand spraying those trays and discarding water from humidity domes. Each plant has a different optimum temperature, seed planting depth, and other preferences, so be mindful of those differences as well.

To learn more about specific differences between plants, search for “Johnny’s Seeds.” This internet resource has growing information on most plants and their methods are tried and true.

Justin Husher is the horticulture specialist for the Cuyahoga Soil and Water Conservation District in Ohio. To contact Justin, email him directly at jhusher[at]

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