How often should I water my plants? The million-dollar question answered

After “What can I do about all these slugs?”, the question I get asked most is “How often should I water my plants?” I would love to say there is an easy answer, but unfortunately the most honest response is “it depends”. There are some rules of thumb, though, that will help you keep your crops hydrated now it’s peak watering season.

Just like humans, plants need water for most of their biological processes, and different plants have different water requirements. Rosemary, for example, grows best in arid conditions (and needs little watering), whereas watercress can thrive even when partially submerged in the stuff. So your watering plan will depend on what you’re growing, the conditions they’re growing in and the weather.

Obviously we should water less during rainy periods and more when it’s hot, but also watch out for the wind as it can be drying. My veg patch is exposed, so when it’s blowy I pay extra attention to the soil’s moisture level. You don’t need a fancy device to do this, just stick your finger in the soil. Even when the soil’s surface looks dry, there may be adequate moisture a little deeper down.

Morning is best. The evening is also an option but can create the conditions for an overnight slug feast

The morning tends to be the best time of day to get to business, avoiding the middle of the day when water evaporates faster. The evening is also an option but can create the conditions for an overnight slug feast if you have as many molluscs in your garden as I do.

Frequent, lighter sprinklings will cause your plants’ roots to develop close to the soil surface whereas generous drinks, provided less often, will encourage their roots to push deeper into the ground, which is what you should aim for. (But again, this approach should be varied depending on the plant and weather – at the height of summer lettuce or rocket may need more frequent watering to manage the heat stress they’re prone to.)

A nifty way of getting water to where it needs to be is to bury plant pots in the ground next to the stems of your thirstiest plants, such as courgettes or tomatoes, and filling them with water. I use recycled plastic pots as I have plenty, but if you use porous terracotta pots (with plugged bases) the water seeps out slower – perfect for when you’re away for a few days.

Think holistically about your garden’s water needs. Install water butts to collect rainwater, especially as your plants will prefer it to mains water. Mulch your veg beds and containers to help retain moisture. And when choosing which plants to introduce to your growing space, consider planting more perennials – such as rhubarb – which need less water once established.