ONE of the joys of my job working in a walled garden in Liverpool is the opportunity to garden with children and young people. The site is leased by Myerscough College, which offers land-based training courses, and their students of basic horticulture each have a small vegetable plot.
One young man is volunteering to keep his hand in over the summer before he starts his next level of training. I have given him responsibility for a flowerbed, and his pride in it, and attention to detail, is raising the bar across the garden.
While students’ classroom time is kept to a minimum, I sometimes find myself in deeper horticultural discussions than I intended, when pointing pupils and their tutors to the week’s priorities.
We gave our collection of tomato plants in the peach house their first feed last week. “But I thought plants could make their own food, using sunlight,” a student remarked. And, of course, he was spot on. Plant “food” is a misnomer. Plants need light, water, and air, and mineral nutrients from the soil. It is the latter that gardeners may seek to supplement by using a “fertiliser”.
Adding some form of nutrients is essential for the effective culture of pot-plants, where the growing medium is finite and will become depleted as the contained plants grow. They need not be artificial. Comfrey is deep-rooted, and can extract plant nutrients that other plants cannot reach. It stores them in the leaves, which can be harvested and used to make an effective organic liquid feed.
Anybody with the common comfrey, Symphytum officinale, on their plot is usually happy to give away some young plants, as it self-seeds rather too freely. If you are wary of invasive plants, you will need to source the sterile variety of Russian comfrey, “Bocking 14”. Either of them will establish quickly, and then you can periodically harvest the leaves, chop them up, and pack them into a bucket or lidded container. Weigh them down with a brick, and add a pint of water. Leave for about a month, and then pour off some of the brown liquid; it needs diluting with approximately ten parts of water to the colour of tea before watering on to your plants.
Comfrey, being rich in potassium, makes a particularly good feed for tomatoes and other fruits. Nettles are richer in nitrogen, and will produce a liquid ideal for feeding leafy crops. If all this sounds too much work, there is a new natural fertiliser on the market, PlantGrow. The bedding plants that I grew from seed this year have certainly responded well to it.
I have long accepted that feeding tomato plants improves yield, but suspected that keeping them slightly on the “hungry” side, to return to animal terminology again, would produce more concentrated flavour in the fruits. Not a bit of it, apparently. Which? Gardening reports that unfed tomatoes have a more watery flavour and, incidentally, thicker skins. They recommend Westland Gro-Sure Tomato Food, at £2.99 for two litres.