Growing plants from shop-bought flowers, fruit and vegetables is an appealing way to get more for less – but it’s not without its challenges. Understanding the risks can help you grow successfully and responsibly
Growing plants directly from purchased flowers, foliage, fruit or veg is increasingly popular. Many of us enjoy the satisfaction from growing and sharing new plants and doing so for free is almost a too good an opportunity to miss. However, it’s important to be aware of the potential plant health risks and how to minimise them.
Plants and plant products imported to the UK must meet strict regulations and checks to ensure they are safe to plant in your garden. In contrast, plants imported for eating or decoration‚ like vegetables or cut flowers‚ pose a lower risk as they aren’t there to be grown on. This means they are checked less than plants meant for planting in your garden. So if you plant a supermarket potato or root a stem from a bouquet, take cuttings, use tubers or seeds‚ you’re turning a low-risk plant into a higher-risk plant. These were safe for their intended purpose, but once it’s in your garden – you run a far higher risk of introducing plant pests and diseases to your garden or the wider environment than if you had bought something that had been through the checks.
Dividing supermarket basil into individual plants in small terracotta pots is a simple way to grow more for free – but it’s important to consider the potential plant health risks
You might ask “why not have the same level of import controls for all plants and plant material, regardless of use?” This would slow the movement of food, affect cost, availability and quality across food supplies. There’s always a balance between trade and protecting the
Measures aimed at preventing the spread of potentially harmful organisms (pests, diseases or invasive species) into the environment. These include sourcing plants responsibly, quarantining new plants and practising good garden hygiene.
biosecurity of our food supply and the wider environment.
So, is this a big fuss about nothing? It might sound unlikely but real issues are encountered more often than you may think. A good example of this would be the exotic root vegetables oca, ulluco, mashua, and yacon that were purchased on the internet and imported to the UK without any plant health checks. These carried a number of high-risk quarantine plant viruses and nematodes which could potentially infect a wide range of plant host species, including
A native plant is one that originated or arrived naturally in a particular place without human involvement. In the British Isles, native plants are those that were here during the last ice age or have arrived unaided since.
Under UK law, quarantine pests and diseases are subject to statutory control and are legally notifiable.
A quarantine pest or disease is:
Not present in Great Britain
or Present but not widely distributed and under official control
And Capable of causing unacceptable economic, environmental or societal impacts if it became established.
One of the ways I help guard against these risks, is by sourcing quality-assured and tested planting material of known origin from a reputable UK supplier. How do we tell if a supplier is reputable? Past experience or personal recommendations can be a useful guide, as can assurance schemes such as Plant Healthy or, in the case of businesses in the UK selling plants online or by mail order, the list of authorised distance plant sellers, which lists businesses registered with the plant health authorities in England and Wales. Careful sourcing is particularly important for food crops. Imported plants, especially from countries outside the EU, have been shown to pose the highest risk to UK gardens, farms and the environment.
Plant Healthy
Plant Healthy is a voluntary certification scheme – similar to FSC for sustainable timber production – which helps businesses, including nurseries, retailers and public, historic and botanic gardens, demonstrate their commitment to plant biosecurity.
Keeping our plants and gardens healthy
You can minimise the risk of introducing new pests and diseases to your garden by
Always sourcing UK-origin and UK-grown material from reputable suppliers
Avoiding material of unknown or suspicious origin – they are often highest risk
Avoiding bringing plant material such as seeds, cuttings, bulbs, plants, cut flowers and foliage back from your travels abroad.
Consider joining an allotment or garden society and other schemes to give you access to discounted plants, seed, tubers,
Can refer to either home-made garden compost or seed/potting compost: • Garden compost is a soil improver made from decomposed plant waste, usually in a compost bin or heap. It is added to soil to improve its fertility, structure and water-holding capacity. Seed or potting composts are used for growing seedlings or plants in containers - a wide range of commercially produced peat-free composts are available, made from a mix of various ingredients, such as loam, composted bark, coir and sand, although you can mix your own.
compost and so on.
Growing “free” plants in containers on hard standing, either under cover or outside, ideally on a pot saucer. This will limit the risk of new pests or diseases infecting surrounding plants or contaminating the soil in your garden.
If you’re keen to try growing from shop-bought produce, some crops are safer than others when handled carefully.
Spuds for free
Seed potatoes have been specifically produced, inspected and tested to give us bumper potato crops. That’s why they are small, healthy, vigorous and certified virus-free. They can also be pricey too. Certainly, more per kilo than we pay for spuds at the supermarket or grocers, which are sometimes referred to as ware potatoes. Imported ware potatoes occasionally exhibit a range of pests and diseases – from scurf to more serious, quarantine diseases like the virus zebra-chip which could put your potato crop and that of other gardeners and farmers at risk. So please don’t plant imported potatoes in your garden or allotment.
If, like me, you are looking to grow potatoes and are worried about the initial cost then consider joining a local gardening or allotment group. Most benefit from discounts on supplies and sharing batches of tubers, seeds and plants can help reduce the cost significantly. If that’s not an option, then please consider growing UK-origin potatoes in containers and dispose of any
Plant-based waste that is suitable for composting, such as dead leaves, clippings from pruning or grass mowing and discarded annuals. Many local councils have green waste recycling schemes if home composting isn't an option.
green waste to the local authority
Composting is the process by which plant material is heaped together to rot (decompose) to produce compost. Garden or kitchen waste can be broken down over time in a compost bin or heap to produce crumbly organic matter that can be used as a mulch, soil conditioner and a constituent of potting compost.
composting scheme once the crop is finished.
If growing supermarket potatoes, choose UK-origin potatoes and plant them in containers to reduce the risk of introducing new pests and diseases to your garden
Exotics like ginger or lemongrass from shop-bought produce
These can be fun to grow, but shop bought exotics can carry risks. Grow them in a pot on a saucer. They’ll do better indoors or in a greenhouse or cold frame and you will limit the risk of introducing any new pests or diseases to your plants or garden this way.
If you want to grow root ginger, I’d recommend growing them in containers, monitoring for signs of disease (discolouration, distortion, etc.) and disposing of the plants in the non-recyclable waste if you see any signs for concern. Disposing of plants in your community green waste where temperatures reached are likely to be higher than in your compost at home, is also an option for safer disposal.
Carrot and parsnip tops
Rooting carrot or parsnip tops in water can allow them to re-sprout. Potted up the resulting plants usually flower the same year, producing lovely delicate umbels, which are great for a range of insects including hoverflies. But please be careful as a number of viruses have been found in both carrots and parsnips imported for food. These plant viruses are harmless to us consumers but can be passed on to other plants in our gardens by
Sap is a fluid that circulates through a plant's vascular system, in a similar way to blood moving through our veins. Phloem sap carries the sugars produced in the leaves by photosynthesis down to roots and other storage organs, as well as carrying minerals and hormones. Xylem sap is watery and transports nutrients absorbed by the roots upwards to the rest of the plant. Some plants leak sap from wounds or pruning cuts, and this is known as bleeding.
sap sucking insects such as whitefly and aphids and by our hands and tools. Reduce the risk by growing the tops of UK-grown carrots and parsnips.
Carrots are cheap and easy to grow from seed. Leave carrots to grow in the ground for a second year and they will produce delicate umbels of flowers which are attractive to pollinators
Brilliant berries – raspberries, strawberries and more
Some online gardeners advocate harvesting and growing seed from purchased fruits such as raspberries and strawberries but bear in mind that these seeds can contain plant viruses, which can reduce plant vigour and berry yield. For best results, start with disease-free, certified stock, you can always propagate extra plants from these by growing healthy suckers, or by taking hardwood cuttings. Raspberries have a tendency to accumulate viruses, they are very popular with sap feeders like whitefly that can transfer viruses from plant to plant as they feed. When we propagate plants from splits or suckers these viruses remain. For this reason, gardeners normally replace raspberries with fresh certified stocks every 7 to 12 years.
Raspberries can harbour viruses that build up over time, reducing vigour and fruit yield if plants are propagated from infected stock
