How to keep a veggie patch going through a dry spell

How you water matters more than how much

When it stops raining and the patch starts looking crisp, the instinct is to stand there every evening with the hose, and that is the version that uses the most water for the least result. Most of what keeps a veggie garden going through a dry run is about where the water ends up and how long the soil holds onto it, and once you get that right you can grow a decent crop on surprisingly little.

Water deeply, early, and less often

A long soak twice a week puts water down where the roots are and encourages them to follow it down, while a light daily sprinkle only ever wets the top 20mm and trains the roots to sit up there in the hottest, driest part of the profile. Early morning is the time to do it, because the soil is cool and very little goes to evaporation, and the leaves dry off as the day warms. Evening watering gets recommended constantly and it leaves foliage wet all night, which is how you end up with mildew and rot on top of a water shortage. Water at the base of the plant rather than over the top of it, and whatever water restrictions happen to be in place, work out how to put your allocation on in one or two good soaks rather than spreading it thin.

Check whether your soil is even taking the water

Dry sandy soil and old potting mix go water repellent, which means the water beads on the surface, runs off to the low spot and disappears while the root zone stays bone dry underneath. The test takes a minute. Water a patch normally, wait 20 minutes and then dig down 100mm with a trowel, and if it is dry down there your soil is hydrophobic and no amount of extra watering is going to fix it. A granular soil wetter breaks the waxy coating on the soil particles and gets the water in, and it is the single best value thing you can put on a dry garden.

Mulch properly

A thick mulch is a lid on the soil, and the difference between 25mm and 75mm of it is enormous in January. Use something coarse like sugar cane, pea straw or lucerne so water still gets through to the soil, keep it clear of the stems, and top it up as it breaks down rather than waiting until it has disappeared.

Put the water where it goes in

Drip line and soaker hose deliver water straight to the root zone at a rate the soil can absorb, with nothing blowing away and nothing landing on paths, and on a veggie bed that is a genuinely large saving over a sprinkler. Run it under the mulch rather than on top. A tap timer is worth it as well, mostly because it stops the classic mistake of getting distracted and leaving the hose running for an hour.

Shade the worst of the day

Above about 35 degrees most vegetables stop growing and go into survival mode, so shadecloth over the bed through a heatwave is not fussing, it is the difference between a crop that pauses and a crop that dies. Fifty per cent shadecloth is plenty for a veggie patch, and it can go over a simple frame of stakes or be thrown over a tomato cage for a few days and taken off again.

Grow the things that cope

Some crops simply handle dry conditions better than others. Silverbeet keeps going long after lettuce has bolted, and rosemary, thyme, oregano and sage barely notice a dry spell. Pumpkins and zucchinis root deeply and will find water a shallow-rooted plant cannot. Lettuce, celery and cucumbers are the thirsty ones, so if water is going to be tight they are the ones to grow in the cooler months instead.

Group them by thirst

Put the thirsty things together at one end of the bed and the tough ones at the other, and you can water the two groups differently instead of irrigating the whole patch to suit the fussiest plant in it. Build the soil up with compost while you are at it, because organic matter holds many times its own weight in water and a bed with plenty of it through it will ride out a dry fortnight that would flatten a bare sandy one.

Shop related products

• Pope Drip Eze 2LH 13mm x 30m. Drip line to run along the bed under the mulch.
• Pope Simple Set Tap Timer. So the soak stops when it is supposed to.
• Martins Organic Sugar Cane Bale 11kg. Coarse mulch that still lets water through.
• Neutrog GOGO Juice 2L RTU. A microbial tonic for plants doing it tough.

Did you know we also stock shadecloth cut to length in 50, 70 and 90 per cent in both 1.8m and 3.6m widths, soaker hose in 10m, 15m and 30m, and granular soil wetter, and the shadecloth in particular is a cut-per-metre line that is not on the website, so give us a ring on (08) 8536 4333 to check what is on the shelf.

More from the garden centre

The mulch, the irrigation and the shadecloth all come out of the garden centre, and if you bring in the measurements of your bed we will work out how much drip line you need.

Keep reading

• How to grow vegetables that are perfect for the South Australian climate
• Seven secrets to growing crunchy carrots in any soil
• The ultimate guide to growing climbing beans with ease

I water in the morning because I know better, and I still find myself out there at dusk with the hose about once a week.

Candeece