Thursday, November 5, 2015

How Do You Water Those Soil Blocks?, Which I'm Sure Will Wash Away Like John Travolta

There are two very good techniques for making sure that your soil blocks are watered correctly:

Fogging our Farm Plants

The fog watering set-up (old style)

The fog watering set-up (old style)

New style brass connectors with fogger

New style brass connectors with fogger

Fog means air and tiny penetrating water particles. Fog watering refers to watering or misting or fogging the plants with super small aerated water particles in abundance over, around, side to side, under and on top of your soil blocks. The tiny water particles naturally mix with air and thus create a living ion of oxygen, so very needed to plant roots that are trying to burst through compacted potting soil.

Aerating your water is a crucial step in healthy plant growth. Fogger nozzles are easy to use and require no agitating of the water before you water your blocks, which one should do if she's using a watering can. Agitate the water by filling the can with a powerful streaming of water into the can so it bubbles and froths up, adding air bubbles to your water. Or, stir rain water very vigorously for the ultimate in healthy, happy plants. But, in the greenhouse or nursery, fog misting is preferred, even though it is usually done three times a day.

We like to be close to our plants, constantly assessing health and speed of growth. We play music for them, or I put on one of my bird CD's which contain songs by many birds for hours and hours. These tricks have been well documented to aid in plant growth. So, by fogging we believe we create a natural environment for soil block growth. The fog completely saturates the plant, root, soil block, and leaves a heavy dew on the leaves and stalk. Coupled with tons of sun and lots of wind and air from recirculating fans, our plants develop thick stalks. Fog and mist will never crush your seedlings.

We also create wire benches for soil blocks and mist from the bottom up, under the benches. We don't miss any spot. The wire benches are used so we get all six sides of the potting block "air pruned". Air pruning eliminates transplant shock. But, at least, the mist should be sprayed over head until the bottom of the block is dripping water.

We use Fogg-it brand nozzles attached to coiled garden hoses that are suspended from the greenhouse pipes and roll back and forth with a little pulley/roller wheel on top of the pipe.

Fogg-it nozzles come in 4 sizes:

  • 1/2 gallon per minute used for newly seeded soil blocks and 3/4" soil blocks.
  • 1 gallon per minute used for established seedlings in the 3/4" soil blocks or vigorous seedlings in other blocks.
  • 2 gallons per minute used for heavy drinking seedlings in the 1.5" block or bigger.
  • 4 gallons per minute used for 2, 3, 4 inch blocks that are growing crazy and very thirsty

We go a few steps further for installation. We used to use Gardena Quick Connect hose ends, (see top picture,) for quick interchange of all foggers. We also used to set them up on Gardena flow regulators, and install the actual fogger on a high quality brass squeeze nozzle, called a thumb valve. This provides the ultimate in control, flow and endless adjustments for different growth rates and tender flower starts. Now, we are using pure brass Quick Connecters, (see bottom picture) because we don't like that the plastic started to break after a few years of heavy use. Plus, we no longer have to change out washer seals. Also, the plastic connectors eventually started to leak, and leaks are NOT good.

So, gardeners rejoice at the availability of super-high quality brass quick connectors with a water stop feature, which means when the fittings are disconnected, the water stops immediately. As soon as the fittings are reconnected, the water flow starts. YOU NEVER HAVE TO GO BACK TO THE FAUCET TO SHUT OFF THE WATER! The foggers screw right into the brass male ends and won't break (as screwing plastic into brass over and over will eventually do) and never need any washers anymore! They also allow twice the flow of plastic quick connect fittings. They are not interchangeable with plastic fittings.

We also have certain commercial mono crops growing in hoop houses that can be built with automatic misters and timers that attach directly to an in-line black or white poly pipes directly over the seedling benches. A little programming gets it done all day without worry. This would be known as drip irrigation using misters. Not really that much more work involved in setting this system up, and it works well for mass planting of seedlings that require the same amount of water every day.

Complete instructions can be emailed or faxed to commercial growers who purchase a commercial Stand Up blocker. Give the Guru an email with your needs. Another great idea is a gentle rose watering from a watering wand with a rose attachment. This is the basic economical way to water soil blocks. Just give 'em a good drenching, and check and water at least twice a day.

Of course, if you're going to purchase a new watering wand, you'll get what you pay for. Surprisingly, you can't get a professional watering wand that will last for longer than 3 years without spending well over 30 bucks! That's the Dramm company who sells the top-of-the-line wand.

Bottom Watering for Soil Blocks

Make a simple bottom watering tray:

  • Screw a wooden lip around the perimeter of some plywood.
  • Line it with agricultural plastic.
  • Level it.
  • Fill with blocks and water.

bottom watering tray

Many people are convinced the only way to raise soil blocks is by bottom watering. This is also known as manual ebb and flow, static evaporation, and water wicking. It is not the only way to water soil blocks, but it is the best way to water if you have very little time to monitor your seedling garden. Let's explain bottom watering and explore the variety of methods used with advantages and disadvantages, and instructions on creating them.

Bottom watering is the manual watering technique that fills a shallow, water tight tray with water up to a predetermined height of water at specific intervals to hydrate the roots of seedlings, transplants, or cuttings. The rate at which water is supplied is determined by the rate of evaporation of the environment, and root wicking caused by plant growth. The amount of water supplied is determined by the size of the plant container (or soil block) and the depth of the holding tray or water reservoir.

Bottom watering can be done manually by watering cans, or automated by timers outfitted with drip irrigation, or with timers on pumps which fill and empty the reservoir, known in the hydroponic industry as ebb and flow (E&F).

If you answer "Yes," to any of the following questions, then you are a bottom watering candidate!

  • "Am I at work for 4-8 hours a day, every day?"
  • "Am I new to soil blocks and gardening?"
  • "Do I have A LOT going on in my life and tend to forget little things?"
  • "Am I going on vacation, or away for the weekend?"
  • "Do I live in the desert?"
  • "Do I want to grow baby greens?"

After viewing a brief discourse on soil block making in Step by Step Instructions, you'll want to have your system of watering prepared in advance of making blocks, since they will need somewhere to go right away.

Big Tip Here: If you are bottom watering, you need to make absolute sure that your blocks are very firm. Make sure and charge the blocker 3-4 times and watch for water oozing out the tops. If not, your blocks could just melt away.

Put your recyclables work!

The fastest and easiest way to start bottom watering is to reuse some of your recyclable containers. Look for aseptic packs, or rice dream and soy milk containers, Styrofoam take-out trays, salad bar trays with clear lids, plastic bottle bottoms, old cake pans, salad green tubs, etc.

Make your blocks and discharge them into the container with about 1/8" spacing between the blocks. After you seed or place cuttings, you won't have to water for about three days, as the newly wet blocks contain enough moisture in them for that time.

Cover your seeds with black plastic to make absolute sure they won't dry out. Check every day, twice a day for sprouts, and then remove plastic immediately. After about three days, you'll want to water your blocks by gently pouring in water on the side of the container, never directly on the block, to a maximum of 2/3's of the height of your chosen block, be it micro, mini, or maxi.

You'll have to watch and keep track of how fast it is evaporating and how fast your plant uptakes the water in order to gauge how often you'll be filling your trays up to the 2/3's mark. Never go over that line or you could drown your seedling. Better to have too little water at this stage then too much as the block itself contains a lot of water pores for emergency use. Only when the plant is well established in the block could it be over watered and pose no threat to growth.

If your block is made from a potting soil that DOES NOT CONTAIN FERTILIZER OR AMENDMENTS, make sure to begin an organic fertilizer program in 10-14 days until your blocks are transplanted into your garden bed. Consult my web pages for fertilizers to use, or my past Blogs for free ideas.

Bottom watering trayBottom watering with a tub

The next best way to begin bottom watering is to cut the bottom out of an old Rubbermaid tub, provided at least 2" of the bottom is salvageable. A jig saw is easiest! Try cutting the bottoms out of any old plastic junk lying around. This works well for a larger blocking system. Or, buy a Hydroponic-grade grow tray right here. Best in the industry!

Lots of soil blocks? Make some custom trays.

The best way for larger scale growing is to make a custom tray out of plywood for the bottom, and 1x3's or 1x2's nailed or screwed around the sides to make a lip. Then, take a spare or old piece of greenhouse plastic (4-6mm) and line the tray and make it water tight. Be sure and sand any sharp edges and wrap it completely and staple, poly fabric tape, or lathe it to the bottom of the plywood. If you decide to staple, use some kind of a tab on top of the plastic to prevent it from tearing, like plastic tabs or even heavy cardboard, as the water will stretch out the plastic and make it loose if you don't secure it firmly. This method takes a little longer to construct, about a half an hour to an hour, depending on your size, and, if you have to rip your lumber down to size, but creates a solid tray that can be used for a few years.

Build shelves for them in a greenhouse (keep it very level), or create a potting block bench top with the option to cover with wire hoops (9 gauge) and plastic for a hoop-bench propagation station! Add a large heat mat with a thermostatically controlled switch and you got yourself a mini greenhouse.

Build a custom hydroponic system

Now, you can take the last option and create a hydroponic system (known as the ebb and flow) with a pump and timer. For this you will need:

  • Your custom-made plywood tray
  • a water reservoir or Rubbermaid tub
  • a little fountain pump
  • a timer (capable of multi-settings)
  • silicone
  • some plastic tubing that fits your pump
  • whatever fittings secures the pump with the tubing with couplings.

Now it's time to assemble:

  1. Build your plywood tray. Be sure to build it deeper for the larger blocks, at least 2" for the micros or minis, or 4" for the maxis.
  2. Drill a hole the same size as your tubing at a corner of the tray and then cover with plastic. That hole will be your drain and fill hole.
  3. Position your tray. As you position your tray make sure it is slightly slanted towards the hole for proper drainage. Position the tray on a bench over the reservoir and secure the pump in the reservoir, silicon the tubing to the hole in the plastic lined tray. Check for proper water drainage and tilt.
  4. Hook up the pump to a timer, fill the reservoir with water, and manually test to see how long it takes to fill up the tray to the 2/3's rule on whatever block you choose. This amount of time will be programmed into your timer to come on once every three times a day.
  5. Fill the tray with soil blocks, and seed or transplant or fill with cuttings and wait three days and turn your timer on. The water should fill through the pump and drain through the same hole.

Mix fertilizer in your water at the 10-14 day mark and watch for rapid growth in order to transplant before the roots spread out too far. You can transplant or pot on the next block and replace them back in the tray, or get them out in the garden.

Make sure to harden plants off properly to prevent stunting of growth. You could, however, keep them in the blocks until harvest, depending on the plant size and length of time until harvest. Lettuce, spinach, baby greens, micro salad mixes, mesclun, basil, herbs, scallions, flowering broccoli, baby kales, nasturtiums, flowers, and spices work wonderful for block to harvest.

Experiment and create for yourself the wonderful options of bottom watering. Be sure to check out our timeless, in-depth and hot information on soil blocking on our blog at

Bottom watering trayBottom watering tray

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