A word of warning before you set about reading this post. On this blog, as well as ramblings about my adventures in Israel botanising, sightseeing and generally enjoying the culture, I will write more technical pieces on my work. Sadly for those more casual readers, this post is of the latter nature. Though I try to keep things simple, some are sure to find this post about propagating seedlings a bit like eating a dry wheatabix for breakfast. I apologise for that, but the milk in Israel really does suck!
As an intern at the Jerusalem Botanical Gardens, a major element of my work is on the rare and endangered plants of Israel. Due to habitat loss and environmental pressures, a sizeable part of Israel’s Flora has become endangered or even extinct in the wild. Ori Fragman-Sapir and his predecessor Avinoam Danin have worked to monitor and record these plants, and propagate them in the gardens. This then allows the rare plants to be distributed and shared with other gardens, and even reintroduced to the wild from where they have been lost.
Almost all of the rare plants propagated in the garden are done so from seed. This means at point of collection wild populations are not caused further damage by plant removal (this would be counterintuitive to the project’s mission). Another consideration is that a large number of the plants in question have an annual life cycle, meaning seed must be collected and resown to maintain a viable stock. So, for the sake of seed stock, reintroduction, sharing and displaying, I will be sowing around 170 species over the next month.
Handling and managing such a collection could very easily become confusing and unwieldy. To prevent this, the JBG, like many other Botanic Gardens, uses a piece of software called IrisBG. The software records details about each plant under an “accession number”; every new plant that comes to the garden (even the same species, but from a new source) receives a new accession number. Not only does IrisBG assist with managing this year’s plants, but it also allows me to look back at previous years and see useful information like germination rates or seed treatments. By collecting and examining this data over a period of years, the handling of each species can be refined for optimum results.
Every year the seeds that need to be sown are chosen by Ori from stock, then processed and given to the interns for sowing; from this point onwards, the seeds and eventual plants are the interns’ responsibility. Each packet of seed comes with information written on it, such as how many plants are required and where these plants are to go. Then, we use the information on IrisBG to make informed decisions on how to treat and sow each species. Lots of seeds require no pretreatment and are simply sown in trays; others require pretreatments such as Cold Stratification, Gibberellic Acid, Soaking, etc. (I will probably discuss these in detail in a future post).
Once the pretreatment stage has passed, seeds are sown into round trays with good drainage in a 1:1:1 mix of coir, perlite and vermiculite. Seeds are placed on top of the soil mix, then covered with a layer of vermiculite about as deep as the diameter of the seed. After a light water, they are placed on a bench in the nursery.
Trays are then monitored every day and watered when required; the weather is pretty cool right now so they are low maintenance. As the seeds are all natives, no bottom heat is required: the conditions should be right for them. When enough seedlings have germinated in a given tray, they can be transplanted. Transplanting is best performed when the seedlings are small: often at seed leaf stage they have a large enough root to be moved. After lifting the seedling from the tray, the roots are cut at the base with a sharp knife; this encourages a thicker, more fibrous root structure in the plant.
Since I have only been working here for two weeks, this stage is as far as my seedlings have progressed. From here, the plants will be moved into different pot sizes depending on their vigour and final destination. Every step of the way, the label and status is updated in IrisBG, ensuring the collection is manageable and allowing others who are not directly involved with the work to locate plants. Though it takes a bit of time to adapt to recording data and using computer systems, I love the efficiency and organisation it provides; for me, managing plants this way is a breath of fresh air. Now fasten your seatbelt, because, if you’re lucky, my next post may just be a detailed piece about using Gibberellic acid to break seed dormancy!