How to Climate-Change-Proof Your Garden

Water woes, wind warnings, drainage dilemmas, and sun stress – gardening’s not what it once was. In fact, with climate change to contend with, growing has become a completely different ball game. So much of what gardeners are now dealing with comes down to managing weather extremes, and whether it’s atmospheric rivers or severe wind storms, climate related events mean we now need to find new ways to keep our plants and gardens healthy. Let’s take a trip through climate mitigation plans many gardeners are now adopting:

Skip the staking!

Once upon a time, we would never consider planting a tree without first hammering in two or three strong stakes to support it. However, with ever-stronger winds hitting our gardens hard, there’s now a different plan in place, and it goes like this: When we anchor a tree with stakes, we over-protect it. Left to its own devices, our tree is more likely to put down deep, anchoring roots which take into account the direction of the prevailing winds. This means when the tree finally outgrows it’s stakes, it’s not left unprotected. Rather, the natural direction of its root growth will keep it firmly anchored.

Sponge gardens

Drought was once more manageable because water was available in unlimited supplies. Now, gardeners are facing more severe droughts for extended periods of time, and with limited access to water. The answer to helping gardens through these tough times is to incorporate more sponge-like materials into the soil. Rather than digging in compost that has matured to a fine tilth, many gardeners are now adding partially composted material to their beds (note: do not include animal manures in compost piles that will not be safely matured though sterilisation). Partially-matured compost contains water-absorbent materials such as fine twigs, straw, and decaying leaves, which lock in moisture, then slowly release it when drought conditions arrive. Biochar (a form of commercially-produced charcoal designed specifically for use in gardens – ask for it at your garden centre) is another water-retentive soil conditioner that can be incorporated into the garden to feed moisture to roots during dry spells

Mulch is magic!

Mulch is a covering placed on top of the soil to reduce moisture loss from the garden. It can come in many forms including organic materials such as straw (check it does not contain herbicide), grass clippings, and compost, or an inorganic layer of, for example, plastic sheeting. Mulches reduce evaporation caused by direct sunlight, as well as air movement over the surface of the garden. Organic mulches have the added benefit of adding nutrients to the soil as they begin to break down. Mulches can be more or less beneficial depending on the type and depth of the material applied. For example, a mulch of 5-7cm deep is more likely to keep the ground beneath cool and moist than a thinner layer. A mulch of loose straw will give less protection from evaporation than, for example, a more dense material such as fine seaweed or compost.

Water-wary

Climate change is not all about drought, with many gardens now being hit by sudden downpours that wash away top soil and leave garden beds saturated and depleted of nutrients. To prevent soil and nutrient loss through heavy rain, consider built up beds which contain your growing medium. During periods of heavy rainfall, soil can also be protected by ‘living mulches.’ These are ground hugging plants that not only help stabilise soil, but prevent it drying out during drought periods. Living mulches can also double as a food source when you choose the likes of prostrate rosemary, marjoram, alpine strawberry, ulluco, and NZ spinach. In the flowering garden, ground hugging ornamentals include Ajuga (check your variety for suitability before buying), the lovely NZ natives, Muehlenbeckia axillaris and Coprosma kirkii ‘variegata,’ and the striking ornamental clover: ‘Red Feathers.’

Climate change doesn’t have to detract from your enjoyment of gardening. As you rise to the challenges it brings, take pleasure in researching new methods of gardening, and new plants to suit what the weather throws at you!