Medical Marijuana Indoor Growing Media

Greenhouse or indoor Medical Marijuana,  has some special concerns that are often quite
different from their outside siblings. Rapid growth is tantamount of indoor
crops, as the plants may be on a short vegetative cycle. Thus, the growing
medium must provide conditions that encourage growth. One other requirement of
indoor cultivation, is that the plants are uniform, having the same growth
rate. A dynamic garden is one where plants grow at the same rate, in a uniform
medium.

The growing medium serves several important functions in the
growth and development of the plants, such as:

* Moisture holding capacity and aeration – The growing medium should provide adequate moisture for plant growth, while retaining sufficient air space for root development. If plant roots are not given adequate air space for exchange of gases, growth will be slowed, and the target date for harvest will be missed..

* Nutrient holding capacity – The growing medium should provide nutrients for plant growth. The pH of the medium needs to remain fairly stable throughout the life of the crop so that nutrients are available to the plants. The ideal medium pH for most greenhouse/indoor crops is 5.5 to 6.5. Also, the medium needs to be able to hold the nutrients against leaching so plants do not have to be fertilized as often.

* Support for the plants – The growing medium needs to have sufficient bulk density to support the top portion of the plant. Lightweight growing medium may not provide sufficient support. The plant may easily fall over on the bench due to improper support or the roots may become damaged during shipment because the top flops about. In hydroponic culture, or plants grown in nutrient solution, gravel or some other means of artificial support is provided.

Reproducible and available – Many growers want to have their
own secret growing mix that produces gi-normous plants. However, the
ingredients need to be readily available for the next crop and they should be mixed
in the same manner each time so the routine is consistent.

Most growers have gotten away from soil based medium in greenhouse/indoor
pot plants. SOILLESS medium is a medium that doesn’t contain topsoil. Several
organic and inorganic materials may compose various soilless media. Some common
ones are:

* Peat moss – Peat moss is a moss plant that grows in heath bogs. Peat moss may vary depending on the source. Sphagnum peat moss is the best. It has a high moisture and nutrient holding capacity:

* Bark – It is best to use aged hardwood or pine bark. Bark may be used as a substitute for peat moss or in tandem with peat.

* Sand – Sand is often used in combination with organic matter, such as peat moss, to increase aeration and drainage. It has a low nutrient holding capacity. It increases aeration to the medium.

* Vermiculite – Vermiculite is heat-treated mica that has high nutrient and moisture holding capacity. It is lightweight and should be used only with organic matter.

These components, along with fertilizer amendments, are
formulated into mixes. They can be mixed by the grower or commercially prepared.
Peat-lite mixes and bark-based mixes are some old school commercially prepared
ones, available at most greenhouses.

Soil sterilization may be necessary for controlling insects
and diseases in growing media.

Some sterilization equipment uses steam as the heat source.
Other soil sterilization equipment contains electrical heating elements to heat
the growing media to a set temperature. Don’t forget, grow American!

Joyce