Many of our orchards are surprisingly vulnerable to the effects of climate change. Not only is physical damage caused by late frosts or strong winds, for example, but the stress caused by unpredictable weather makes our trees much more vulnerable to pests and diseases. This all has the effect of reducing yields.
So what strategies are there for protecting our orchards?
1. Be a detective
It’s worth spending time researching your soil and any patterns you or others have noticed in your area. For example, have you observed late frosts, frost pockets, water logging or drought stressed plants? Look at the state of other trees in your area and see what kind of trees are thriving. Are these trees associated with damp or dry soil?
2. Don’t put all your eggs in one basket
A polyculture of different types of fruit or nut means that we can spread the risk. If plums are badly hit one year then at least we might get sweet chestnuts! Because our climate is changing, we should all include at least one experimental tree or shrub to see how it fares in our region. Here’s a bit more information about how to incorporate some less well-known fruit and nuts into orchards.
3. Choose your varieties carefully
If you choose fruit trees with fewer chilling hours, you’re more likely to get higher yields if the winter is unseasonably warm. Choose varieties and rootstocks with good disease resistance, taking into account what you know about your area. For example, if you are growing in clay soil that can be prone to water logging, consider using M116. M116 has some resistance to Phytophthora.
In addition, include some bigger rootstocks, if you have the space. More vigorous rootstocks tend to have a longer life span and be more robust. This means they’re more able to cope with extremes of weather.
4. Feed your plants
Create a comfrey patch right beneath your apple tree and use the leaves as a mulch. Comfrey roots are so deep they won’t compete with the fruit tree. If you use the non-self-seeding cultivar, Bocking 14, you won’t need to worry about it dominating.
Comfrey and other deep-rooted mineral accumulators bring up nutrients from lower down in the soil. This means that the leaves can help feed your orchard plants. You can cut comfrey four times a year and simply place them on the surface of the mulch circle to break down. Weeds can also be used as a mulch or can be shoved under a bush to rot in-situ.
You should always try to include nitrogen fixers in your orchard. As their leaves drop and their roots die back, the nitrogen they have fixed will become available to the other plants to take up. Another quick way to add nutrients to your orchard plants is to add human urine – the perfect fertiliser.
5. Protect your trees
Shelter belts are a great way to protect your young fruit plants and soil from strong winds. These should be planted reasonably densely to slow down and generally baffle the wind. Prevailing wind is generally from the south west in summer and north or east in winter, but make sure you take into account what you know of your site.
It’s worth including some nitrogen-fixing, shelterbelt shrubs such as Elaeagnus x ebbingei and E. umbellata in your design because they have the added benefit of providing edible berries. If thorniness is not a problem, Sea Buckthorn, Hippophae rhamnoides, has the same set of benefits.
If you know your soil can get too wet, you can plant your trees on mounds to give them a better chance of establishing. You could also plant moisture-loving tree crops or grow very thirsty plants such as willow. These will remove some of the water from the soil.
Always include a wide mulch circle which has a sheet membrane beneath it – cardboard, for example. Sheet mulching is essential for suppressing weeds from germinating or growing into your mulch circle, and will help absorb water. The simplest mulch to get hold of is usually woodchip, which has several additional benefits, but there are plenty of options. Chipped young willow is particularly good at protecting apple trees against scab.
In very dry areas, you should choose plants wisely and also consider adding features such as ponds, swales, water butts and rainwater harvesting structures. All of these will slow down the movement of water across your land and store water.
Adding a shelterbelt and including some understorey crops with your trees, for example black currants or saltbush, will help reduce the airflow through your orchard. This will also raise the local air humidity. Adding organic matter to the soil surface, mulching and avoiding digging will also help keep soil moist and protected from the eroding effects of wind.
6. Build biodiversity
If you do everything above, you will automatically be creating conditions that will boost biodiversity because you’ll be providing a lot more habitats and a lot more food sources. Support the above and below ground biodiversity still further with these wildlife-friendly behaviours: not digging, not adding artificial fertilisers, not using pesticides and not being too tidy.
Adding features such as log piles or choosing wildlife-friendly plants will add to this. The more complex your orchard ecosystem, the less likely that any one organism will dominate and become a pest.
The more complex your orchard ecosystem, the healthier the plants and the higher the yields.
Although the future is uncertain, there are lots of strategies to help future-proof our orchards and we should be adventurous and experimental in our plant choices, designs and practices.