Since planting the fruit trees I’ve been investigating what I could use to under-plant them that will be beneficial to the them, but also might serve other purposes, such as providing resources for us. In permaculture, these kinds of associations are known as plants guilds. This post talks about the considerations I took is designing fruit tree guilds for my apples and pears.
Guilds are like next-level companion planting, with a twist. A guild is a grouping a plants, trees, animals, insects and other components that work together to help ensure the health and productivity of a system. Stability (resilience) is produced when elements are cooperating.
Each element in a guild can serve multiple purposes that input into the well-being and productivity of other members of the guild. It is usually built around a central component. In this case, my strip of deciduous, soon-to-be-espaliered fruit trees are the central elements. In nature, guilds occur in layers, with canopy trees, under-storey trees, shrubs, herbaceous plants, ground covers, vines, roots and mycorrhizal fungi. Obviously I won’t be able to achieve all these layers with espaliered fruit trees in an urban garden, but I can mimic nature by ensuring I include plants that contribute to the overall health of the system.
Chosen carefully, other plants can provide things that will benefit the trees. This could include ground cover that shoulders out grasses that would otherwise compete for root space and nutrients, or plants that attract predatory insects and pollinators. As my urban garden is to be an intensively cultivated space, I am also looking at plants that can provide other outputs as well, including food and medicine crops.
All of the components of a natural ecosystem should serve a function (or several functions) that support each other like the strands of a web. One strand on its own may be weak, but the combination of all the strands together add to the overall strength and usefulness of the web.
Roles in Plant Guilds
Below are the roles that I am looking to fill in my fruit tree guild and some thoughts about the plants I am considering:
- Ground cover
- Structural Elements
Accumulators (‘Diggers & Miners’)
Plants with deep tap roots are often great accumulators of nutrients that are too deep for other plants to reach. The tap roots pierce deep into the soil, well below the reach of neighbouring roots, seeking out their own supply of minerals and nutrients. They aren’t competing with other yielders, as they are harvesting otherwise inaccessible nutrients.
Accumulators can serve multiple benefits. Comfrey (Symphytum officinalis) can provide both medicinal outputs for us and also makes a fantastic “chop and drop” mulch, where the out of reach nutrients can be deposited on the soil surface. I’ve chosen to plant Russian comfrey near to the base of each tree. The Russian cultivar is sterile and doesn’t produce seed, which will help contain the spread of the plant. Once comfrey gets it feet settled it can be hard to get rid of. I will also sow borage (Borago officialis), a cousin of comfrey, in this bed.
I remember gardens from my childhood where feature plants stood solitary in bare beds, stripped of weeds, the soil around exposed to the sun. The chunks of grey soil would crumble to dust in my hand, dry and lifeless. We only have to look at nature to see that the healthiest soils are those that support a thick polyculture of plant-life, retaining moisture, encouraging wildlife and returning nutrients to the ground.
Battling weeds in order to maintain clear bare soil is not only futile, but can be damaging to the plants that you DO want to grow. That’s why, for areas I am not actively cultivating, I tend to let nature take over and do her thing, until I am ready.
Ground covers are especially important for immature guilds where there is more likely to be ground exposed to the sun, and where grasses may be competition for trees. I have chosen several varieties of oreganum (Oregnum spp.) and thyme (Thymus spp.) for beneath my trees. They form a spreading clump and over time form considerable ground cover. What’s more, they are easily dividable to produce more plants (and save some money!). In addition to the obvious culinary outputs, they also have medicinal benefits, being useful in lung and throat infections. The fragrant aroma also has its benefits, as described below.
I’ve also planted some young strawberries. They seem a bit lost amongst the pea straw this time of the year, but I’m hoping that I’ve planted them early enough to take full advantage of the warming soil in spring, so they can set their runners before the start of summer.
If I had more a bit more space in this area, I would invite a wider variety of plants (“weeds”) to move in, and harness the vigour of those plants that are naturalised to the area. Some of these may have a place in other parts of my garden eventually. However, this bed is in zone 2/3 so I am looking for plants with multiple utilities that I can harness and harvest, to maximise productivity in a small space.
Including plants that can provide mulch to the guild will save time and energy, as they can be chopped and dropped on the ground and left to break down into the top soil. This helps build soil structure, assists aeration, helps retains moisture and release nutrients. Rhubarb and artichoke apparently work well in this role with fruit trees. However, as my trees are in a narrow space and the soil is relatively poor, I am hoping my comfrey takes off well enough to fulfill this role.
Protector plants can work in a number of ways. Aromatic (strong scented) plants tend to distract or confuse potential pests that would otherwise damage crops. These include plants such as mints, basil, lavender, lemongrass and coriander, as well as the aforementioned oreganum and thyme. Some of the same plants can also attract beneficial predators, such as hover flies and lady bugs, that feed on the pests. All of these plants provide other harvest-able outputs.
Other plants such as nasturtium and alliums such as garlic, chives and leeks can deter potentially damaging insects. Nasturtiums are meant to be particulary suited in apple tree guilds.
Protectors may also be sacrificial. These are plants that a pest might favour, drawing it away from precious crops. The long term challenge with sacrificial plants is that they may create an environment that enhances the pests ability to reproduce.
Regardless, multi-species system will always have greater resilience than a monoculture. Not only is the risk spread, and the variety of crops increased, but the relationships between the plants can be mutually beneficial to stave off disease and pestilence.
Attracting a variety of insects is beneficial for two main reasons. Firstly, there will be no fruit without pollinators. Both apples and pears (and many other fruit trees) require cross-pollination to yield fruit so I want to lots of flowers to shout out to passing insects that my garden is the bar that they should be drinking in. I don’t know exactly what time of year my fruit trees will flower yet so I need to ensure that I keep my floral advertising for an extended period.
Secondly, attracting a variety of insects prevents any one species of insect becoming a problem, as different species predate on one another. Providing an environment that supports healthy populations of lady bugs, hover flies, lace wings and mantis’ can help keep pests in check enough to avoid reliance on insecticides.
As well as having flowering plants around the trees, I plan to plant a wide variety of flowering perennials across the garden to encourage bees and other pollinators down this corridor. As well as the plants already mentioned I will include flowering herbs such as dill (Anethum graveolens), coriander (Coriandrum sativum) and yarrow (Achillea millefolium) along the sunny edge can attract pollinators and insect predators. There will also be a perennial flower garden in zone 2 near to where the vege beds are planned. More on that later.
One role that I have not yet decided on how to fill in my fruit tree guild design is that of the nitrogen fixers. As well as having plants that accumulate nutrients from down deep, it is important to include plants that increase the amount of nitrogen in the soil. Nitrogen is the most important element for plant growth and there are certain plants, particularly of the legume family, that symbiotically work with soil bacteria to “fix” nitrogen in nodules in their roots. Vetch, alfalfa, peas and bean are all legumes that are “nitrogen fixers”. I’m considering planting some peas or beans to grow up the espalier supports while the trees are young. I also recently bought some red clover (Trifolium pratense) seeds, which I may use here.
There can be structural elements within a guild, such as those that provide support of shelter. In our urban garden I’m making use of the perimeter fence to both support my trees as I train the branches, and to provide some protection from the prevailing northerly. A wormery or compost might be considered a structural element in a guild, potentially providing shelter, nutrients, support and mulch to a guild.
Summary of Plants Selected
|Ground cover||Encourage Pollinators||Deter Pests||Accumulate minerals||Shelter||Support||Provide mulch||Fix nitrogen||Medicinal||Culinary||Aesthetic|
|Apple – Freyburg||y||y||y|
|Pear – Conference/ Red Bartlett||y||y||y|
|Apple – Hetlina||y||y||y|
|Oreganum – variagated||y||y||y||y|
|Oreganum – Greek||y||y||y||y||y|
There are other roles that can be filled within a guild. Supporters, climbers and shelter providers are three roles that might be needed in a guild on a larger scale project, such as a forest garden, but I don’t have need for them in this urban space.
Designing Plant Guilds
What I’ve described here is far from a complete summary of how to create a fruit tree guild. I’ve focused on my own needs for an urban setting. However, there are so many other plants that would fit into the guild roles described above that would suit different climates, environments and settings. A good place to start any guild design is with a companion planting list, which gives you an idea of which plants play nicely together and which don’t.
For me, writing this has been a useful way to contemplate the initial design for my fruit tree guild and work through a process of determining what fits best with what. I have to admit that this will be trial and error. I’m mixing a mere smattering of experience, with a minimal amount of common sense, some wisdom from my herbal studies and knowledge from reputable sources on guilds. The plants I have chosen, while carefully researched, have been influenced by my own needs and preferences. I’m almost certain that no matter how carefully I have considered them, some will not be suitable and others will fail so I’ll may need to reconsider plants chosen for each role. It’s a learning process, and a lesson best learnt by failing.
FAIL = First Attempt In Learning – I learnt that from my daughter, who in some ways is already much wiser than me.
Be bold. Have a go.