Thanks to a generous helping of rainfall and a smattering of sun, spring is finally underway. And the gardens are showing it too; weeds are popping up in the beds, shrubs are putting out fresh shoots, and the mowers are being fired up at least once a week.
However, as nature wakes from its winter slumber, so too do the pests. Slugs are tunnelling in the tubers, aphids are sucking the sap from the salvias, and box-tree caterpillars are blighting the Buxus. This begs the question, beyond mundane, mechanical removal, how is best to combat the spring-time assault?
The importance of organic insecticides
Long gone are the days when “pesticides” would be the prevailing answer. Having proven to be a major contaminant of our waterways, earth and air, these chemicals, over time, catalyse biodiversity loss and even compound the original issue by encouraging pest resistance.
Jenny X, National Trust, says: “The importance of using organic methods to control pests is vital for the environment. Inorganic compounds can X”
With the popularity of inorganic treatments waning, gardeners are beginning to consider more sustainable and environmentally-friendly alternatives. To this end, one of the most effective and natural bug-repellents is what is referred to as “tobacco juice”. Created by boiling or steeping nicotine-rich tobacco leaves in water, this brownish tincture serves as a “green” (and powerful) insecticide. Biochemically, the active ingredient in tobacco is toxic to many of the nasties that feast and fornicate in our beloved borders. Application is simple - once cooled the mixture can be sprayed or wiped onto the leaves of all plants.
The recipe is hardly new, and can be traced back to The English Physician - a work published in 1652 by botanist Nicholas Culpeper. In his seminal book of herbal lore, Culpeper recommends the use of tobacco juice to exterminate lice on children's heads. If it's good enough for children, it's good enough for our roses.
Growing tobacco at home
The next step is getting one’s hands on tobacco. You could, of course, reach for the commercial stuff in your drawer, or nab some from the nearest shop, but if we are to keep this project as organic as possible, why not grow some? We are gardeneers, after all. As long as you do not sell any of the produce commercially, private tobacco farming remains perfectly legal in the United Kingdom.
Last year - in the name of organic insecticide - I decided to undertake this venture and it proved to be one of the most enlightening and exhilarating spells I have ever had in my garden. Tobacco, derived from the genus Nicotiana (of the night-sahde family), is native to North and South America. This means it favours bright sunshine and light, sandy soil - all of which are less than guaranteed in Blighty. So, to see one’s tobacco seeds germinating and established in the garden is a deeply rewarding experience.
First, I purchased 500 sand-like Nicotiana Sylvestris seeds on Etsy, for just £5. To put that value into perspective, a single tobacco plant - given the right conditions - produces an average of 4 ounces of dry, cured tobacco. That’s over 100 grams. Though remember, your tobacco leaves will not need to be dried and cured; they can go straight into the tincture, raw. This means you will only need to successfully establish a single crop to provide enough insecticide to last from spring to autumn.
Just remember to remove the flowerheads and collect the seeds from the dried pods so that the entire process can be repeated next year. Each pod is likely to have over 500 seeds, so you will never have to buy again.
To germinate successfully, scatter the tiny seeds - as if seasoning a good steak - in a tray of quality, light, potting-on compost (I find incorporating potash to be a secret weapon). Always sow clear of the last frost, and place the tray in a greenhouse or a plastic growhouse if you are concerned by low temperatures. Tobacco seeds do not like to be left in the dark, so burying them in the compost is a bad idea. Simply drop them on the soil and very lightly push them down with a thumb or forefinger to ensure contact is made. Keep the soil moist with a mister (a traditional watering can is too powerful and will wash the seeds out of place) and wait for at least one month. When spring is in full swing, and the seeds have seen enough sun, you will start to see wonderful, tiny green leaves.
If you make it this far, congratulations are due. Germination is, arguably, the most challenging phase of tobacco growing. From here, provided they are treated with due delicacy, your plants should grow happily.
Harvesting your crop
As the seedlings get larger, they begin competing with each other for water and nutrients, so extract them from the tray and work them, individually, into larger containers. As they continue to grow - and providing you have the space - you may wish to take them outside for full sun, or even plant them into the ground. Remember, a plant’s growth potential is limited by the container in which it is sat. If you have a small garden, feel free to keep them in large pots, watering regularly.
Depending on the amount of sun, after several months the plants will be ready (most likely late summer) to harvest. To ensure a good amount of bug-exterminating nicotine is in the leaves, cut them from the stem when they are at their most mature. Tobacco plants tend to ripen from the bottom to the top. The leaves should be large, verdant and tough. The roots and stems have more modest levels of nicotine, though they compost well and will serve as great food for your tobacco plants the following year.
If all has gone to plan, you will have a lot of harvesting to do, so why surrender some of the plants or seeds to friends and family? While typically referred to as an annual, Nicotiana Sylvestris is more like a short-lived perennial and can be overwintered outdoors with a thick layer of mulch.
The white-trumpeted plant, Nicotiana, is a beautiful, unusual, and fantastically utile curiosity piece for British gardens this spring. So, instead of crawling about in your borders, following slime trails and picking slugs with your hands from the perennials, set yourself a horticultural challenge, and brew some tobacco juice this year.
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