Jerry talks about some helpful garden species

“When I was seven years old, I discovered a method of growing abundant fresh vegetables all year round. It’s about using volunteers to do the work for you. Let me introduce you to some of them.

Swine Cress (Lepidium didymium) started growing in my garden from the very moment I turned the soil. Coriander (Coriandrum sativum) is another happy volunteer – it’s been cropping itself happily in my garden for eight years. Three months ago, some volunteer ‘Sweet Bite’ tomatoes popped up in the compost, so I trained them up my balcony.

Tomato volunteers can turn up pretty much anywhere. You’ll find them in disused garden beds – rather like weeds – where crops have been allowed to set seed. They’re particularly common where people are making their own compost, so I’m going to show you how to take advantage of these willing plants.

The first thing you’ll need to do is to be able to recognise your volunteers. Ten days ago, I sowed an area with some compost and some corn. In amongst the corn are loads of different volunteers. When a seed germinates, the first leaves produced are not true leaves. They’re called cotyledons and plants fall into two groups – the dicotyledons produce two embryonic leaves; and the monocotyledons produce one embryonic leaf. Corn is a classic monocot. I don’t have many monocots in my garden, but they include bananas and onions. I grow far more in the way of dicots – these include crops like peas, carrots, lettuce and tomato.

While learning to identify seed leaves is a great way of simplifying plant identities, it’s the next leaves – the first pair of true leaves – that start to give away the nature of the plants you’re looking at. You can often use them to identify plants by their families – for example, the carrot family have distinctive foliage. Smell is also a profoundly good way of identifying a plant – for example, you can smell a seedling like coriander.

With a bit of practice, you can start spotting the plants you want to keep. For instance, tiny red leaves tell me I have some Chinese Spinach ‘Mekong Red’ volunteers. Also, the crimped true leaves of another seedling tell me it’s endive; while some greyish leaves belong to huauzontle – a type of spinach.

Time to Transplant

The best time to transplant seedlings is when they’re really young. In the compost and corn crop, I’ve got some volunteer Stinking Roger (Tagetes minuta). It’s an unfortunate name for such a useful relative of the marigolds. It does have a really potent smell and I use it as flavouring for potato salads and controlling nematodes – but I don’t want it to grow right here where it’s popped up. These plants will become too big to grow alongside the corn, so I’m going to transplant them elsewhere in the garden. A good practice is to put them into a bucket of seaweed solution so they don’t dehydrate en route.

While many volunteers are welcome to grow where they sprout, some have to be transplanted, like the Stinking Roger. In a bed of warrigal greens and amongst the pumpkins, some tomatoes have popped up. However, I’ve already grown tomatoes in this soil within the last year, so they have to be moved – I need to rotate my crops. Crop rotation is the way organic gardeners prevent the build-up of pests and diseases – and tomatoes and their relatives attract a whole range of them. So I’m going to pot this tomato instead.

When transplanting seedlings, it really helps to hold them by their leaves, not their stems. Try to save as many roots as possible and water them in with a seaweed solution. That really helps to reduce transplant shock.

Also use clean pots and fresh propagating mix, so you don’t get any diseases. I’ve transplanted the volunteer tomatoes deeply, so they can produce extra roots along the stems and produce stronger plants.

The sort of plants that do really well as garden volunteers are members of the carrot, cabbage, cucumber and tomato families. All these plants have relatively small seeds and don’t mind being kept in slightly damp soil. Just give them a little bit of a drink and they’re done.

I’ve been press-ganging volunteers to grow for me ever since I was a pup and I wouldn’t garden any other way. The sheer numbers help suppress weeds. If you recognise what you’re growing, you’ve got food on the table within days – and best of all, it builds confidence for budding gardeners. I’ve got 2,000 seedlings here, so I don’t care if a couple of hundred die. The slugs and snails are welcome to them.”