If you’re experiencing dry climate conditions, drought or have limited water resources, food gardening may be challenging. Don’t despair! Careful selection of drought tolerant food crops, water-wise gardening practices and improving your soil can all help.
Droughts involve both high temperatures and extended periods without rain. The longer gaps between rainfall cause soils to dry out to greater depths. Heat waves occur when there are multiple consecutive days at very high temperatures. Heat waves can cause injury to plant tissues and in extreme cases, plant death. A deep, fertile mulched healthy soil with vegetation holds a vast amount of water. Unlike shallow bare soil with minimal organic matter. So, a key goal is to improve soil moisture-holding capacity and available nutrition. This will help our plants to grow through rainfall shortages and heat waves. Before we look at drought tolerant food crops, there are other factors to consider for dry gardens.
How Much Water Do Vegetables Need?
On average, most vegetables require around 2.5-3cm (1″) or so weekly. However, this varies considerably depending on the climate, soil characteristics, wind, temperature, stage of plant development and plant variety. Some crops are very reliant on consistent moisture. e.g. Lettuce, corn, cauliflower and coriander. Whereas others can tolerate prolonged periods without watering, like Mediterranean herbs.
During dry times, I aim to water as infrequently as the plants I’m growing will tolerate. However, I also consider if I want the plant to produce an abundant harvest or just maintain minimal growth. i.e. stay alive! I hold off watering during or after rain, and reduce the frequency of watering during cooler weather. If it’s hot or windy, plants transpire more moisture so have higher water needs.
How much water vegetables need also depends on the irrigation method. For example, drip irrigation, a soaker hose, ollas and wicking bed systems provide a gradual release of water at or below soil level. If you water by hand with a hose or watering can, you may need to water more frequently. If this is the case, you might want to consider some water-wise strategies especially if you have limited water resources.
How Often Do Plants Need Watering?
Vegetables/Pot Plants: In hot, dry weather I water daily except where I use ollas, water spikes, self-watering pots, drippers and my homemade potting mix. These are all buffers that hold moisture longer. I water less frequently in cooler or cloudy calm weather. Usually every second or third day.
Seedlings and newly establishing plants: I usually water daily during hot dry weather for the first fortnight or so. Then 2-3 times a week after that or if they are under shade cloth. In cooler weather, I can usually get away with watering every second or third day for the initial two weeks. Developing healthy roots and shoots is vital at this stage of growth so I don’t skimp on their water needs.
Fruit trees: During establishment in the first couple of years, heat waves or prolonged hot dry weather, I aim for twice a week. Or weekly during a normal summer with reasonably regular rainfall.
Ornamentals with some drought tolerance: Typically get watered weekly in summer and as needed in winter.
Mature drought tolerant ornamentals: This varies with the plant from every 3-4 weeks to never! When I do water, I try to give the plants a deep drink with liquid seaweed rather than just water.
Drought Tolerant Plant Adaptations and Survival Strategies
A lot of drought hardy plants have inbuilt defense systems that allow them to adapt when there is low soil moisture. These are a few of the strategies of drought tolerant plants.
- Deeper root systems to tap moisture away from the surface.
- A symbiotic relationship with mycorrhizal fungi help the vast majority of plants to cope with water stress and increase drought resistance.
- Swollen storage roots (tubers, rhizomes and lignotubers) to retain moisture and nutrients.
- Silver foliage helps reflect sunlight, cool leaves and reduce evaporation.
- Releasing a chemical cocktail of sorts to counter heat and water stress, allowing them to survive for short periods of time.
- Some plants put the ‘pause button’ on their growth. Other species close up their leaves or grow smaller leaves, adapting to the conditions.
- Fruiting crops often abort those fruits they can’t support.
- Some plants show stress by dropping their leaves. I look for these clues so I know which crops might be needing support.
- Fine, thin, waxy, succulent, leathery or hairy leaves.
- Originating from a desert biome. Many plant species adapt to Mediterranean, arid or hot dry climates.
- Bush tucker or native food plants.
I grow quite a few resilient crops that handle drought with far less water. They’re hardy and cope well, continuing to grow despite the climate hardships.
Drought Tolerant Plants Grown from Seed and Seedlings
Seed grown plants often adapt better to dry conditions once established than seedlings from nurseries. Commercially grown seedlings are usually cultivated in very controlled conditions including temperature and consistent moisture. They may be more likely to suffer transplant shock or be less adaptable to harsh conditions when they leave their comfortable environment!
Self-sown seeds or ‘volunteer’ plants that pop up in our gardens are often the hardiest in my experience. Plants that germinate in harsh conditions are resilient and hardy. I want more of those species in my garden!
Mature fruit trees with an established root system in a larger pot are likely to be more drought hardy than very young immature trees. This may vary depending on the cultivar.
How to Select Crops for Dry Climates Carefully
Some crops are extremely inefficient water users. Corn and melons for instance, are water guzzlers! Perhaps buy those varieties you don’t have space for or water resources to support. Consider growing some of the most water-efficient foods instead.
When selecting seed varieties, look for “drought hardy” or “drought tolerant” in the description. Local seed banks and seed saving groups will also usually have a good source of seeds adapted to growing in your microclimate conditions. I save seeds from crops that have grown well in my soil during dry times as this is a characteristic I want to preserve in future plants. Learn seed saving and propagation skills so you can choose the best plants from your own garden at no cost.
List of 75+ Drought Tolerant Foods
Drought Hardy Vegetables, Herbs, Flowers, Fruit & Nuts
There are a wide variety of heat and drought hardy or tolerant food plants for diverse climates. Once established, many plants can endure short dry periods. This list is not exhaustive but rather primarily from observation in my own subtropical climate. You may have different soil types or microclimates and adaptability may vary. However, this is a good starting point if you’re trying to grow drought resistant, heat tolerant food gardens that can survive climate challenges.