This week was altered by a Covid outbreak and I spent time conducting more research on greenhouse work. Below is a write up of the basics of what I have learned:
Water Management: Water management is one of the most important factors of successful greenhouse propagation. It is a tricky art to perfect, especially for a farm like Alamere which specializes in rare ornamentals and medicinal plants which all have very specific watering requirements as opposed to a vegetable farm. Each plant requires its own specific microclimate, and the more specialty plants a farmer is cultivating, the more complicated the greenhouse routine. Greenhouse work is truly an art and requires a high level of skill and intuition. Alamere uses a bottom watering strategy which consists of placing start trays into a tray full of water and usually fish fertilizer. As well as a timed sprinkler system with mini sprinklers placed in the heated cold frames, which are essentially mini-greenhouse environments built with heated wire and PVC siding. They offer a cost-effective way to have heat in the early spring without the requirement for an expensive heated greenhouse. The timers are set depending on the weather and will usually be set off around every hour- an hour and a half on hot summer days for around fifteen minutes. Watering is especially important for small and sensitive starts.
Temperature regulation:
Temperature regulation is important in keeping water retention as well as keeping the greenhouse at the ideal germination temperature: 68-72 degrees Fahrenheit. The strategy Alamere Herbs uses to regulate temperature during hot summer days is to have misters go off in the greenhouse increasingly as the outside temperature rises, going off as often as 30 seconds every 10 minutes when the temperatures reach the 80s. The greenhouse also has a lot of ventilation, temperature thermostats, and shade cloths in the summer months. Shade cloths are a highly cost-effective method to regulate temperature. They are made out of loosely woven polyester or aluminum and have varying degrees of sunlight blocking ranging from 5%- to 95%. It is believed that plants only require 10% of sun exposure to complete photosynthesis, but is recommended that shade cloths in Western Washington require 50% light exposure. The shade cloth is held upon an outside frame and it is important that it is not touching the actual greenhouse surface as the would counteract the cooling effect.
Germination Mix:
The germination mix that Alamere Herbs uses consists of 40% pumice stone and 60% peat moss. The pumice stone adds tilth and texture to the soil to create air spaces to hold seeds and leave room for their growth. As well as to hold moisture. The peat moss is hydrophilic meaning it repels water which looks like holding moisture and slowly releasing it as the H2O molecules are repelled by its surface. It is also very sterile which helps in reducing pathogens and fungus outbreaks in the greenhouse.
Fertilization:
Alamere Herbs primarily uses liquid fish fertilizer as it is cost-effective and offers burn-free nitrogen and other primary nutrients without having to use chemical inorganic fertilizer. They also use chicken meal pellets for a slow release of nitrogen. They also occasionally use blood meal or alfalfa meal. During the Greenhouse lesson, we talked a lot about when to fertilize and why to avoid fertilizing before the seed germinates and produces a radicle and the cotyledon begins to push to the sun. A seed is a lot like a chicken egg, it is equipt with the nutrients and nourishment to get it to the stage of hatching or germinating, and once it emerges in the world it is hungry for outside nutrients. Once the seeds emerge from the soil Alamere begins a fertilizing schedule of one to two times a week depending on the type of plant. Every time you water nutrients are rinsed away so it is important to stick to a fertilizing schedule as the new plant begins to grow.
Containers:
Alamere uses various types of containers to germinate in, largely using 72-128 trays for early germination, or soil blocking trays. Once the start has been established the plants more to 3-inch pots, and for plants like madrone that have long taproots, special pots that encourage taproot growth, and cut them off at a certain point once they reach an air hole on the bottom
Overall I view plant germination as a sort of alchemy or magic to recreate natural growing habitats and create perfectly sculpted micro-climates. Greenhouse work is a complex and beautiful art form that requires skill and heart.