Seed Starting, Soil Blocking, and Looking Forward to a Cutting Garden

There is something particularly satisfying about starting seeds while the snow flies and the wind blows.  Blessed with weather from both Lake Erie and Lake Ontario, the lake effect is particularly harsh today. So snuggled down in the basement, I’m thinking of the future, of spring, of the potential in the seeds I sow.  Until the weather turns the corner, there is no point in working outside in one of our unheated greenhouses. So until then, I work on starting “cool” flowers. These are flowers that can go in the ground early, can take cool temperatures, and even some light freezes.  The plan is to eventually plant most in an unheated high tunnel, and some outside under the protection of frost cloth. What flowers seeds can be planted now you ask? Flowers that like cool conditions! People in Zones warmer than our 6B have the luxury of starting these flowers in the fall.  These plants take off like gangbusters when the soil warms. In our climate we can start these early, cool loving flowers, earlier than the typical “6 weeks before the last frost” recommendation, and enjoy blooms in the spring. Examples of flowers that enjoy cool growing conditions and are perfect for a spring bouquet are burplerum,

Ammi, Daucus Carota, campanula, snapdragons, poppy, bachelor buttons, godetia, fever few, sweet william, foxglove, and sweet peas.

     Soil blocking is based on a principal of root pruning. When air touches the tiny roots on the bottom of the block, it is naturally pruned, making for a heftier and stronger root ball.  Coupled with some shelves, and shop lights, you can start a lot of seeds and soil blocks in a small space. Using heat pads for bottom heat, and humidity domes are not absolutely necessary, but are definitely helpful as soil temperature is actually cooler than the air temperature in a house.  A good source to read about “cool flowers” and soil blocking is in Lisa Mason Ziegler’s book, Cool Flowers: How to Grow and Enjoy Long-Blooming Hardy Annual Flowers Using Cool Weather Techniques.  Lisa is a fellow flower farmer, and has perfected flower farming in her urban farm in Newport News, Virginia.

     When using a soil blocker, the soil mix used is the opposite of the light airy mix you would normally use to germinate seeds.  Instead, like making mud pies, the soil must be wet and dense. Here is Lisa’s recipe for a soil blocking mix. Other formulas can be found on line.  Espoma makes a form of green sand and rock phosphate powder. They can also be found insmall quantity containers as a mix at Lisa’s on line store,

Mix together: 

16 cups of sifted peat moss

4 cups of sifted compost

¼ cup greensand

¼ cup rock phosphate powder

Add 6-8 cups of water to make a wet soil that will easily be released from the blocker.  Getting the consistency right takes a little practice at first. If the blocks fall apart, the soil is too dry, if they fail to release, they are too wet.  I find mixing the ingredients well and adding water, and then letting it sit over night often makes the best blocks. Here are some photos of a small ¾ inch blocker, and a larger 2 inch blocker.  They are available on line at Johnny’s Seeds or Amazon. Also below is a photo of my shelf and light set up. Standard shop lights available from Home Depot or Walmart work. Once the plants germinate, you’ll want to adjust the lights so they are about 6 inches above the tray of plants.  You do not want the plants to stretch and reach toward the light as they will become thin, leggy, and weak. Instead, using the chains that come with the shop lights, adjust the lights so they sit above the plants by about 6 inches or so. Not too close that they burn your tender young plants, nor too far that they stretch (think Goldilocks).

Below is the large soil blocker, a photo of ¾ inch soil blocks that are growing and my tray and light shelves.

Trays can be purchased on line at Amazon, or ask your butcher if you can purchase some styrofoam meat trays for a few cents each.  You can also save your own meat trays. Be sure to wash them well with soapy water.

Soil blocks need to be watered every day, without leaving standing water in the trays.  Using a narrow nozzled watering can, I pour water along the edges of the trays and around the openings left on the trays. It soon becomes apparent when the blocks have absorbed sufficient water.

The goal of soil blocking is to start a variety of seeds early, in a small space, and get them outside, hardened off, and planted as spring is beginning.  The aim is for a 3-4 inch plant to go outside. If you find that your plants are out growing their small ¾ inch block, you can easily “bump them up” to the larger 2 inch block (the ¾ inch block fits directly in an indentation in the 2 inch block), or pot them into 6 packs.   Bumping them up works as well, but takes more room, as does use of the larger blocks or 6 packs. If you have a heated space where you can set up your shelving unit and lights, that is ideal. A heated basement or an unused bedroom works as well.

Hardening plants means aclimating your young plants to cooler outside temperatures prior to planting outside.  A covered porch or carport is ideal for this. Ideally, a hardened plant can go directly into the ground once the ground is warm enough to plant.  The plants listed above can take cool temperatures, but be prepared with frost cloth ready to cover them if freezes or prolonged cold temperatures are predicted.

Some hacks for starting seeds is to place the seeds in a small jar lid, plastic or aluminum works well.  Many seeds, like snaps are realllllly tiny. Use a moistened toothpick to grab a seed and place it in the soil block’s indentation.  Be sure to follow packet directions about the need to cover the seed or expose it to light. If they need light I will use a fine sprinkling of vermiculite to barely cover the seeds, but keep the seeds from being washed or blown away inadvertantly.  If the seeds you start in soil blocks are long and linear, and don’t sit nicely on top of a soil block, push at least half of the seed vertically into the soil block so they get good soil contact.

I hope I have given you some food for thought, and that you will consider starting some early season flowers.  As the snow flies, it is nice to see something growing. This makes the anticipation of spring all the better. Sitting down with a seed catalogue and a cup of coffee (or wine) is a perfect way to start the process.  Plan a cutting garden with easy to grow “cool flowers”, and with a few tools, and time, you will be rewarded with Mother Nature’s gift of color, scent, and beauty. Share this time with your children and you have started a life long journey and love of gardening.

Happy Gardening!  Carrie Kling, Windy Acres/Horticulture, a flower farm and grower of specialty cut flowers.  www.windyacreshorticulture, 716-628-6007