Reusing Soilless Mix and Forest Compost
When the indoor or outdoor crop is finished, the mix can be reused, meaning that the grow medium can be used over and over again. This is beneficial, because after each crop is done, the grow mix retains its investment value, since it can be reused indefinitely. The chart shows how mix volume increases year in and year out. Only new fertilizers need to be added for each additional grow shown.
All organic nitrogen sources, such as blood meal, fish meal, feather meal, earthworm castings, chicken manure, and canola meal are effective for a single outdoor growing season. Phosphorous needs to be replenished each year. Bonemeal and rock phosphate work well independently or as a combination.
Mineral potash sources such as greensand and crushed granite extended their usefulness beyond a single season. The minerals will break down slowly over time, releasing potash to the roots. Fast-acting potash, good for a single season, is available in kelp meal and wood ashes. Kelp meal also provides most of the necessary trace minerals for the plant. Adding Epsom salts when watering adds magnesium and sulphur.
Grow mix is best reused outdoors, because the outdoor environment harbors a different balance than an indoor climate. If indoor mix is not treated with a good dose of 35% hydrogen peroxide (2 to 5ml per gallon) or calcium peroxide in between crops, plants will be more susceptible to disease. If grow mix is reused indoors, a peroxide treatment is a must, or the leaves may develop strange-looking rusts or growths from the contaminated mix.
Grow medium can harbor root disease that thrives in the indoor climate. If the mix is moved outside and dug into the earth, the balance in the natural environment will take over. Reused indoor mix that has shown root disease and harbored excessive mite populations can be transferred outdoors to grow large, healthy plants. The outdoor balance is different, and a strong, acclimatized strain can thrive there and fight off any negative properties, such as root fungus, that may exist in the mix.
Nevertheless, when growing outdoors, a poor quality mix and a weak strain often promote other problems. For example, a weak strain may develop leaf spot fungus, while a plant growing next to it in the same mix will be totally healthy. Another example is that of two identical cloned plants grown side by side outdoors in the same mix. One plant fertilized often in 20 gallons of mix may thrive, while the other plant with no fertilizer applications in 1 gallon of mix is serious bug dinner.
Using hydrogen peroxide (H202) definitely reduces potential problems when the mix is reused indoors. H202 will shed an oxygen molecule to form water and atomic oxygen. Oxygen on its own will destroy anaerobic bacteria and viruses as well as provide oxygen to the roots.
Here is a list of many reusing techniques for outdoor cultivation. These methods should be done one month before transplanting, but if preparation and transplanting happen on the same day, results will be more than sufficient.
This method uses containers that are 5 to 20 gallons. For garbage cans, a 12-inch (30cm) hole should be cut in each bottom. Then a screen is stapled into the bottom from the inside of container. Garbage bags with holes in the bottoms also work.
Perlite and / or half a bag of steer manure can be used to make a layer (1 to 4 inches) on the container bottoms. The manure layer is the ticket.
The used mix (about one 4.0 cubic feet bale’s worth) can be laid onto some sort of tarp while removing all roots and stalks. Mixing on a tarp, in a large bin, or in a cement mixer makes it possible for thorough combining of all the materials.
The next step is adding one bag of composted steer manure, one 9kg bag of earthworm castings, one 5kg bag of Welcome Harvest Farmtm Flower Powertm, and 3 cups of fine dolomite lime. Adding 1/3 to 1/2 part soil (pH near 7 is best) stretches the cost.
Adding perlite, sand, vermiculite, and calcium peroxide (i.e. Grotektm Oxycal or Soil Blastertm) are customizing options to give plant roots more air. Perlite and sand allow water to drain well, while vermiculite holds water. Calcium peroxide is purchased in a powdered form and gives a slow release of oxygen and will also break down to form lime.
Another option is to use any recipe from pages 61 to 63.
After the mix is thoroughly combined, the garbage cans or bags should be filled and placed outside at the site in the spring. If the mix will be left longer than two months, a grower should place a cover over the mix in order to prevent the fertilizers from leaching, which is wasteful. If rainfall will be low for the area, then it is possible to prepare sites earlier without adding a cover.
Plants during vegetative growth should be fine without additional fertilizer, but a grower can apply the odd half full-strength application of a fertilizer for flowering plants.
For alternative feeding methods, there is the chemical cheat sheet on pages 67, 97 or the organic hydroponic recipes on pages 97 to 103, and hydroponic formulas on pages 95 to 96.
Mix should never be allowed to dry, which will cause the plants to wilt. Remember that giving a heavy dose of water in the middle of the day can give the plants a mild shock, especially if the water is from a lake, spring, or glacial melt.
Water should be at pH 6.0 to 6.6 during vegetative growth, and at 5.5 to 6.4 during flowering. The temperature should be around 70°F. Roots obtain nutrients more effectively when the temperature fits their needs.
Watering with cold water (below 70°F) in the cooler parts of the day goes more with the flow of the root temperature, because it will heat up during the part of the day when growth is most productive.
Photosynthesis will slow down when light levels lessen, and therefore watering is best at that time, so it can saturate the mix and be utilized for the next productive daylight time.
Production can be taken further by maintaining a warm root temperature, around 70°F, during darkness, to allow plants to make a more solid root system. Adding sand to the mix can raise the root temperature. Highly productive hydroponicists maintain this constant root temperature for their plants.
Taking all the mix to a sunny, safe site with a somewhat decent water supply is a good way to start. A 2-foot square hole should be dug about 1-foot deep. Holes can be smaller, but they should be no less than 10 to 12 inches in diameter. It is best to estimate the potential production of the strain to make an accurate and nonwasteful-sized hole.
Rocks, metal fencing covered in thick black plastic, or wood can be used to build a raised bed 1 to 2 feet high. Spreading one bag of manure on the bottom of the raised bed gives a definite edge, because it allows for a meal later on when the roots reach it. The next step is to dump a bunch of old mix (about one bale’s worth or 4.0 cubic feet) into the bed.
Then it is recommended to add one bag of composted steer manure, 3 cups of fine dolomite lime, 3 cups of blood meal, 6 cups of bonemeal, 3 cups of greensand, 3 cups of kelp meal, and one-third part soil. The soil can be sandy, clay-like, boggy, forest compost, or topsoil. Ideally, the overall pH will be about 6.0 to 6.5. All materials should be mixed well with a claw, a pitchfork, in a cement mixer, or wearing gloves to keep the hands clean and smell-free.
Adding a material that gives more air to the roots will boost yield by a significant percentage. Perlite or sand will give extra drainage and add more air to the grow medium. Vermiculite will give the mix more air and increase its water-holding capacity. Calcium peroxide is a powdered material that will break down into oxygen and lime. It can be added any time to fine-tune the texture.
It is critical when mixing all products not to disturb the manure layer that lines the bottom.
During budding, any (half to full) recommended rate of a commercial product is effective. Plants should be watered generously during hot periods, with amounts that will saturate the mix well.
For other fertilizing methods, there are references in the chemical cheat sheet on pages 61 to 63, or organic hydroponic formulas on pages 97 to 103.
The water should be pH 6.0 to 6.6 during vegetative growth and 5.5 to 6.3 during bloom. The temperature should be around 70°F. At least one 9 to 15-foot stake will be needed to support a healthy, high-yielding plant strain in this mix. It is not too much for one plant!
Other cultivation options are the use of either garbage cans, other containers, or the 2-foot square site. The first step is to thoroughly mix about one 4.0 cubic feet bale’s worth of old mix with one bag of steer manure.
Another bag of steer manure lining the bottom of a can or hole is important for success. Using one bag of composted steer manure in a hole, or half a bag in a 20-gallon container, allows two bucks to go a long way. Now a plant can be transplanted into the mix.
A grower can supplementally feed every week, or every second week with any commercial product designed for flowering plants. The fertilizing application can be at a rate of half to full strength. Other feeding possibilities are described in earlier in this chapter 3 with hydroponic and organic hydroponic formulas that will work well. The chemical cheat sheet on pages 61 to 63 shows more feeding methods with inorganic plant food.
These fertilizing techniques are very similar to those of the indoor program. All mixes should be soaked well during dry conditions. On a regular basis, applying ten gallons or more of solution per plant in the peak of summer may be necessary for plants in garbage cans, especially in heavy-sunlight areas.
To feed plants from the water source while making life simpler, the following watering items may be used: a rechargeable battery pack with a 300-gallon-per-hour pump attached via a DC-to-AC inverter, a solar pump, or a portable gas pump. All that is needed is a fertilizer-mixing unit attached to a garden hose. A direct feed from the end of a hose or a capped hose end with 1/4-inch lines going to various plant sites does the job.
One more option worth trying is the one-third compost trip. In this case, one to two parts of decomposed compost are added to two parts of the reusable mix. Cheap and light perlite, sand, vermiculite, or calcium peroxide can be added later to allow for more aeration to the plant roots. Perlite and sand allow for better drainage, and vermiculite holds water.