Green Horticulture - 1 of 5

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1 Green Horticulture - 1 of 5 September-October 2014 page 67 Issue 169 BRITISH HOLIDAY & HOME PARKS ASSOCIATION 2014 Rufus Bellamy, BH&HPA National Adviser on conservation and environmental management, examines green space management and how daily decisions can boost value to wildlife This article addresses the challenges of day-to-day management of a park s natural environment including mowing the grass, watering the plants, dealing with weeds and keeping boundary hedges in good condition. Weeds One of the most common questions that environmental assessors of the David Bellamy Conservation Award Scheme (DBCAS) are asked is, Should we use chemicals to deal with pests and weeds? While the Scheme does not call for parks to go organic, a lot of environmental benefits come from taking a low or no chemical approach. Spraying with herbicides or pesticides can contaminate the soil and kill much more than the plant or insect intended - so removing links from the food chain and having a knockon effect on biodiversity. One of the problems faced by gardeners trying to stop using non-organic chemicals is that these man-made products have killed off many of the natural predators, such as ladybirds and lacewings, which take longer to re-establish than the pests that they eat. This can mean that when the organic move is made there can be an immediate increase in the number of pests with no natural defences around to help. There are some natural products that can also be used to deal with insect pests and which are useful as a stopgap when moving on from the use of chemicals. One of the most popular is horticultural soft soap, which can help reduce populations of whiteflies, mealy bug and thrips amongst others. Working with nature Organic pest control starts with good design. The more diverse the park is, in terms of its planting and design, the more robust it will be to pests as no single species will be able to dominate. It is wise to ensure that plants have been chosen for their disease resistance and are as healthy as possible. Nature can help to deal with any pests (so-called biological pest control). According to the Royal Horticultural Society (RHS) 1, Biological control is the use of natural enemies to control pests. This can be done by introducing various predatory insects or mites or parasitic wasps, or nematodes that infect the pest with a fatal bacterial disease. This technique is mainly used in greenhouses, but some biological controls, especially pathogenic nematodes, can be used out of doors. There are a number of companies which sell a wide range of helpful minibeasts. For example, Ladybirdplantcare has a range of controls, including, not surprisingly, ladybirds to tackle aphids. Ladybirds should be applied when the aphids are present on plants and the temperatures are above 10 C although best control is gained at C, the company advises. Release in early morning or late evening from May onwards until mid-august by gently scattering over affected plants. 2 The Royal Horticultural Society advises that: Weeds can be controlled without resorting to weed killers. Cultural or organic control measures rely on killing or restricting the weeds by physical action, from manual removal to smothering, burning and using weed barriers. The RHS website is full of useful advice 1. For those who have to use chemicals, for example to deal with particularly intractable non-native invasive species (see below), it is important to ensure they are approved for use in the application and that staff have the necessary training to use them properly. The manufacturer s instructions should be followed and every effort made to limit contamination (e.g. use of a spot application rather than spraying). continued

2 Issue 169 page 68 September-October 2014 Green Horticulture - 2 of 5 Battling invasive plants When it comes to getting rid of unwanted plants, one of the biggest challenges is posed by non-native invasive plants such as Japanese knotweed, Himalayan balsam and giant hogweed. The problem with these is that they can out compete native species, spread out of control and even cause structural damage. Some, like giant hogweed, can harm people. Indeed they are thought of as one of the key threats facing biodiversity worldwide. Nationally, according to Natural England, dealing with problems caused by invasive nonnative species costs the British economy in excess of 2 billion annually. Dealing with these tenacious species normally involves a mixture of physical control and the use of chemicals, often over significant periods of time. For example, guidance from states that: Clearing the leaves and stems of Japanese knotweed or giant hogweed that are above ground and then removing soil contaminated with roots, rhizomes (underground root-like stems) and seeds can provide faster results than just spraying with herbicide. 3 Water wise Given recent stormy weather, water conservation in park grounds might seem low priority, particularly for parks still recovering from the impact of floods. However it s something that s worth keeping in mind, particularly during the hot summer months when water supplies (and many rivers) are at their lowest. It is also a way of saving money on utility costs. A good starting point is to water a lot, but infrequently, as this will encourage plants to develop good roots. In appropriate situations it s also a good idea to spot water, using a watering can rather than a hose or sprinkler. If the park has hanging baskets and planters, highly efficient self-watering systems are available that use a reservoir and wicking system. It is possible to design a park management regime to save water. For example, mulches (such as chipped bark) on borders and flower beds stop water evaporating (and improve the texture of the soil). Planting drought-resistant plants is also an option (see RHS website for options 1 ). Raising the cutting level on grass helps it survive with less watering (it should bounce back even if it goes a bit brown at the height of the summer). Rainwater harvest The next step in saving water is to get water from somewhere other than the mains. Many parks already go to great lengths to collect run-off from roofs in water butts. Putting these in is a great project (and something everyone can get involved with). Rainwater is great for plants and better than tap water for topping up a pond (as it contains less of the nitrogen that can stimulate algae to grow). A step up from water butts are grey water collection systems that collect, store and treat water (to varying degrees) from showers, toilets and other sources. According to the Royal Horticultural Society: Plants can be watered with shower, bath, kitchen and washing machine water (from rinse cycles), collectively referred to as grey water. It varies in quality and may contain contaminants such as soap and detergent. Fortunately, soil and potting composts are effective at filtering them out and the residues can sometimes act as a mild fertilizer. Some parks have also invested in large-scale drainage systems that stores water underground for reuse. Such systems can provide water for gardening. Not only do such collection systems save water, but they can even help to reduce the effects of flash floods by controlling the release of water into the environment when heavy rain hits.

3 Green Horticulture - 3 of 5 September-October 2014 page 69 Issue 169 Go peat-free One of the best green decisions to make is to go peat-free. Lowland peat bogs (from which the peat that s used in gardens is extracted) provide a uniquely valuable habitat for many animals and plants and are under threat. According to Natural England, of the 70,000 ha of lowland peat bog left in the UK, less than a tenth is in pristine or near natural condition. Peat is used for a wide variety of applications, but luckily there are now all sorts of alternatives to peat from composted bark and wood waste to coir and animal manure - which can be used to cover the majority of horticultural needs. There are now even wool-based composts for seedlings. 4 When buying, check the label and if it doesn t say peat-free then it probably isn t! Many parks already make their own peat alternative by composting garden and other organic waste. Not only can compost be used as a soil improver or mulch, it is also a great way to keep waste management costs down. A compost heap can also provide a valuable habitat for a wide range of creatures from slow-worms to grass snakes. Composting will require the construction of one or more composting heaps or bays (best positioned in a warm, safe, sunny spot), but this can be done relatively cheaply using, for example, old pallets. Another alternative is to buy a commercial composting bin or barrel or even a wormery, which can make an excellent talking point for visitors and a focus for children s environmental activities. Composting works best when the ratio between brown waste, such as shredded wood, leaves and shredded paper etc., and green waste, such as grass, weeds and vegetable peelings, is right. A 50:50 mix should work. Air should be allowed to circulate through a compost heap and turning compost helps speed up the process (as does adding a commercial activator). Composting is something that can involve visitors as well as staff put out organic waste bins to collect suitable material for the pile (meat is best avoided) and, if there is any compost to spare, offer it to customers to take away. Composting provides a good way to get rid of two of the biggest horticultural waste headaches grass and leaves. Leaf mould, which can be made in a mesh container or by collecting fallen leaves in a black plastic sack, is a great mulch. Grass can be mulched as it is cut (using a mulching mower) this returns nutrients straight back to the lawn and also removes the need to compost or dispose of the waste in any other way. Although composting is a good way to get rid of wood waste, leaving fallen timber and brash in situ is important for wildlife a woodpile or even a rotten log is a very valuable habitat for all sort of insects, amphibians, reptiles and other animals. Go green at the garden centre Horticulture can require a lot of purchasing decisions. There is normally a greener option; so it pays to consider purchases carefully. The first question to ask is: Do I need it? The next question a great spur for creativity is, Can I reuse something to provide the thing I need? Parks have been busy reusing things in this way. From co-opting old tyres or barrels to create raised beds or small herb gardens, to reusing old bottles to store water or to act as planters (or even the walls of a greenhouse). The options are endless from using old crushed bricks instead of gravel to utilising old sleepers for pathways, it is possible to upcycle an amazing array of things. There are however some things that need to be purchased. To reduce the park s environmental footprint, the most efficient version of whatever machine is required. With wood products, such as park benches and decking, the wood should be certified as coming from a sustainable source (look for the Forest Stewardship Council s FSC label). Wood products also need paint and preservatives here look for products that are water-based, VOC-free and non-toxic. The Natural Gardener website provides items such as biodegradable coir pots (to replace plastic), watering cans made out of recycled metal and planters made from recycled cement bags 5. One other question when shopping for new gardening equipment is, What should I do with my old stuff? To help solve this problem, the Conservation Foundation has come up with the Tool Shed project. This is a tool recycling project, run in association with HM Prisons, which gives new skills to prisoners and which has already saved tonnes of waste. Old tools can be donated at a large number of collection points across the country. 6 continued

4 Issue 169 page 70 September-October 2014 Green Horticulture - 4 of 5 Plants to purchase One of the key buying decisions is: What plants and seeds should I buy? The best approach is to start by seeing whether it s necessary. That s because one of the best ways to source plants is to do it yourself. Providing there is space for a greenhouse, it is possible to collect and propagate many plants. The use of carefully gathered cuttings, saplings and seeds not only ensures that species are grown that are appropriate to the park s location (and which have maximum benefit for wildlife) but can also save money on buying bedding plants and other horticultural necessities. However, certain wild plants are protected against uprooting, cutting, picking, destroying or selling by the Wildlife and Countryside Act The same can be said for another potential approach and that is do nothing. If time is not of the essence, it can be a good idea to see what natural colonization and regrowth will bring. Particularly in ponds and other aquatic habitats, plants can arrive and establish themselves surprisingly quickly. If routine ditch maintenance is being carried out, then that s a great chance to get some new plants for the park s pond or lake. Go local At the plant nursery the type of flowers, shrubs and trees to look at should, if possible, be determined by location. Wherever possible, local native species that provide nectar for pollinating insects and seeds and berries for the birds should be used. Plants that provide food and shelter for birds, insects and other animals for as long a period as possible are best. For example, Hedgelink (a partnership dedicated to Britain s hedges) advises that: If you can, include a range of different species to provide food throughout the year willows and blackthorn for early season nectar; hawthorn, bramble and rose for summer flowers and autumn berries; ivy for autumn nectar and late winter berries. 7 That said, some exotics and non-native species can play a role, particularly those that provide nectar, for example, the buddleia used in many parks butterfly bars. Choosing local native varieties will provide the greatest benefits to local wildlife and will also help make the park an integral part of the surrounding landscape. The importance of choosing local species was highlighted recently by the problem of ash dieback, and the threat posed to the country s trees by pest and diseases brought in from abroad. Given the challenge presented by this, it is vital that any new trees that have to be bought are purchased from reputable suppliers that can guarantee disease-free stock. For wild flowers, whether buying seeds, plants, bulbs, shrubs or tress, Flora Locale, a group that provides advice on buying native flora, recommends that planting stock is obtained from a grower that specialises in British wild plants and which can source identify all supplied stock 8. Cut back on cutting back For planting the main message that the David Bellamy Assessors give out is that it pays to cut back on cutting back. Less structured, informal areas such as long grass areas, brambly hedgerows with lots of vegetation at their bases and wet boggy patches all add wildlife interest. This is backed up by Natural England. Don t feel that you have to be too tidy. Leave some areas undisturbed, especially between March and May, the agency advises. Piles of leaves and twiggy debris in a hedge bottom, or out-of-the-way corner, will shelter frogs, mice and hedgehogs, and the seeds in dead flower heads can be valuable food. Let a patch of grass grow longer, as this encourages wild flowers, provides shelter for small mammals and food for some butterfly caterpillars. This approach can, of course, create problems if customers complain that such areas look messy. However, many parks have proved that it is quite possible to incorporate wildlife areas in amongst more formal park areas and

5 Green Horticulture - 5 of 5 September-October 2014 page 71 Issue 169 have used signage to explain what they are doing and to get customers on side. Hedges Leave trimming your hedge until late winter if you can, advises Hedgelink 7. Hedgerow berries and other fruit provide vital food for birds like fieldfares, redwings and other thrushes throughout the winter. The earlier you cut, the less food will be available to help these birds and other wildlife survive through the most hostile time of year. And never cut during the bird breeding season (1 March to 31 August) unless you have to, for safety reasons. Hedge maintenance is one example of work for which it pays to look at more traditional approaches. These days, hedge cutting is often carried out with a mechanical flail; however this can damage the health (and structural integrity) of the hedge and harm the wildlife that lives in it. More traditional methods of management, such as hedge-laying and coppicing, can be better for nature. Finally One more thing to consider is to get customers to put out food for the birds. After all, when it comes to conservation, as in so many areas of life, every little helps. l Further information 1 Royal Horticultural Society: 2 Ladybirdplantcare: 3 Dealing with Japanese knotweed, giant hogweed and other invasive plants: (search for Japanese knotweed, giant hogweed and other invasive plants ). Further information and identification sheets can be found at: 4 Wool-based composts: 5 The natural gardener website: 6 The Conservation Foundation: 7 Hedgelink: 8 Flora Locale: