Top 10 items for your seed-starting set-up

by Lori Krishnan

Anxiously awaiting the start of spring, I pore over seed catalogues like the rest of us with this particular affliction. Garden porn: it’s my personal favorite of the many terms for these glossy pages filled to the margins with lush foliage, plump tomatoes, and bursting blossoms. I demonstrated remarkable restraint this season and ordered nothing. All my seeds will come from Hands on Harvests and the backlog of veggie and saved flower seeds squirreled away in the chilled darkness of my basement. But what to do with those seeds? And how to turn some of them into those productive plants I so desire?

First, I need equipment. I covet a multi-tiered shelving system with pre-installed lights. I can't afford one for many reasons; that ramblers aren’t so rambling is one of them. So here is a list of equipment I’ll use this year with brief discussions of positive and negatives of each selection.

The List:

· Shelving

· Lights

· Trays

· Pots

· Starting medium

· Clear plastic garbage bags

· Dilutable fertilizer

· Box fan

· Heat mat

· Timers

Shelving: Use what you have

What I have: a metal storage shelf from Home Depot. I don’t know the brand, but it is coated “wire” and adjustable. A wooden shelf or solid plastic/metal shelf would be fine too, but managing water spillage could become a problem. I like my choice of shelf because I can adjust the height of my lights and position them with ease. Ambient light filters through the shelves, and I can see everything that falls through onto the floor. It minimizes hardware and none of the fixtures have to be permanent. The shelves can revert to much-needed storage when I’m done. Need I go on?

Lights: Not as expensive as you thought

My grow lights are a motley crew. My first year was anomalous, using equipment borrowed from Fairfax County Public Schools. The uncertainty of the early pandemic meant my staff partner sent me home with eight trays of seedlings and several shop lights the afternoon everything shut down. Those lights are gone. What I’m left with is a rusty shop light that came with the house and some inexpensive LED lights. Two of those inexpensive lights are “grow lights”. Do you need lights marketed as grow lights … NO. LEDs and halogen lights are it. Incandescent lights are unnecessary, harder to find, expensive, and wasteful. LEDs and halogen lights will keep your electrical bill low with all those hours of use and last longer. They also provide only the wavelengths of lights plants need to grow: blue and red.

Trays: Plastic planting trays vs. aluminum catering trays, no holes

Why do I make a point about the lack of holes? Trays kept outside require ventilation and drainage, so those trays should have holes. But my trays are indoors, and I don’t want water draining all over my basement floor or onto any trays (and electrical lights!) on the shelves below. So, trays without holes are mandatory. Plastic vs metal, well, I’m going to find out if the material of your tray makes any difference by using both. Whatever knowledge remains from my freshman year physical science class tells me that metal conducts energy, therefore its more likely to conduct heat AND cold. Generally, plastic is a poor conductor by comparison and should provide a better barrier to plant roots and any pooling water within the chill environment of my basement. But no matter the material, everything gets a good spray with diluted bleach solution and a good dry out.

I use the same solution used in household cleaning: 1/4 cup bleach: 1 gallon water. I don't sterilize soil, but buy seed-starting mix every year. What I sterilize are trays, egg cartons, and anything I'm mixing my soil in or with (like a spoon).

Pots: So many choices, or none at all

The key thing about whatever contains your starting soil is that it be sanitary. Certain mold and bacteria are deadly enemies when gardening. Consider your seed-starting environment to be your own personal NIC Unit, and your seedlings to be wee infants getting their extra dose of Vitamin D under the bili lights. That means repurposed pots or newsprint need a quick spray of diluted bleach solution and to dry out. My choices are some recycled paper pots and some repurposed paper egg cartons. As for no pots at all, we’ll see how that goes in the mini-greenhouses. But there are also coir pellets on the market that eliminate the need for pots. One less worry concerning sanitation. I may try those next year.

Starting medium: Even more choices

I do my best to maintain thrift these days. But I draw the line at baking my old potting soil to sanitize it. Besides, I have small children and that kitchen is always in use. So, I bought the cheapest material per pound. However, be aware that you only need unfertilized potting medium of any type. Those peat and coir plugs on the market fit the bill nicely. Both materials provide a good balance of drainage and moisture retention to start seeds. I do recommend purchasing coconut coir over peat for environmental concerns. Coconut coir is a natural byproduct in coconut-growing regions, whereas peat bogs are carbon sinks that take thousands, if not millions, of years to re-form under conditions currently disappearing with every passing milquetoast winter.

Clear plastic garbage bags: Multi-use greenhouses

I mentioned that my basement is cold. One way of overcoming that is creating a greenhouse environment. The lights provide light, obviously, but also heat. The trays and medium provide somewhere for the roots to go. But the air surrounding everything also needs good humidity. I overcome the cold and dry air by covering my plastic and metal trays with clear plastic garbage bags. Lights gets through, moisture and heat stay in. One added benefit: bacteria and mold spores stay out. Basements, especially in this region, are notorious for their mustiness. It’s practically unavoidable. So to reduce the introduction of those microorganisms through the air, cover them up, and only go in when it’s time to water. When you’re done, use them for your garbage and recycling routine, using different ones next season.

Fertilizer: Something smells fishy

You don’t need it right away. Fertilizer only becomes important once the seedlings reach a specific stage of development. It’s also used in ridiculously diluted amounts. If not properly diluted, your fertilizer will burn and kill every last seedling. I picked up Alaska Fish Fertilizer with a 5-1-1 ratio of nitrogen, phosphorus and potassium. Other, strictly chemical, fertilizers are on the market for houseplants and other purposes, but I landed on this one because it’s easy to mix a batch in a 1-gallon container without complicated measurement. I can also apply it to my garden in later months without adding to already adequate phosphorous and potassium levels.

Lori adds: I don't follow the package directions at first. Fish emulsion is too strong following package directions of 1 tsp/qt. I start with 1 tsp/gal to avoid any potential of burning the seedlings. More later once it's time to pot the seedlings.

Box Fan: Did I leave the window open?

Later, once the seedlings reach a decent size, they’ll need to develop some strength in those stems. Brushing your hands across the tops will help. But a bit of additional air circulation will double-duty by creating gentle movement and will help refresh oxygen and carbon dioxide balance in the room. Again, this is for several weeks in the future.

Heat mat: My new toy

Laugh all you want. It’s essentially a waterproof electric blanket. They’re not absolutely necessary, BUT I’m trying one out this year. The intent is to mitigate the cold, especially in the root regions of these trays. My upper trays have the benefit of heat from the lower light sources. My lower trays have no such cushion of warmth. One of my lower trays will have the heat mat below it to test whether this additional warmth boosts the success of my little beauties.

Timers: Key, but confusing (for me)

We all have tech which seems so simple, but for some reason mastering it remains out of our grasp. Thus is my experience with plug-in timers. My first year, I woke at 5 AM to plug in lights and unplugged them at 9 PM. It was all religious devotion and a heavy dose of early pandemic anxiety. But do yourself a favor and buy a timer. You'll have one less thing to worry about. My best advice, find a timer you can easily program and use it for everything. If you use one for Christmas lights, or a lamp around your house, use that one. Timers are key to keeping the lights on for at least 12 continuous hours. Your seedlings sprout and grow best with lots of regular, continuous light.

Now that you know my set-up and how randomly put together it can be, try one of your own. You’ll hear from me next when those seeds arrive. Until then, happy catalogue browsing!

Lori Krishnan is an HOH Grow a Row program mentor and Fairfax Master Gardener who donated more than 300 lbs of produce in 2021.