Watering Guide for Summer Vegetables

Vegetables naturally have higher water requirements than many other drought-tolerant ornamental plants. Despite this fact, many well-meaning gardeners unintentionally overwater their vegetables. Not only does this waste a precious resource, it can also weaken and promote disease in plants.

What follows are suggestions on how to responsibly use water and still keep your vegetables healthy. Keep in mind these guidelines are for mature, summer vegetables, which should have well-established root systems that can find moisture deeper in the soil.

If youíre planting seedlings or directly seeding any summer vegetables, itís best to water these daily until theyíre established.

Factors That Affect Watering

How much water do your vegetable plants need? Unfortunately, there isnít one answer that fits all gardens. The amount of water your plants need depends on a few different factors.

Soil structure. A sandy soil has limited water-holding capacity, so you will need to water sandy soils more. Whereas, clay soils and soils with high organic matter content hold water much better and wonít need as much irrigation.

Air temperature. Soil dries out faster when the outdoor temperatures climb. Plants will need more water during hot spells.

Plant variety. Certain vegetables and their cultivars are more drought tolerant than others. Check your seed packages or plant tags to see how much water is recommended for individual varieties.

Humidity. The lower the humidity, the higher the evaporation rate is from your soil. Youíll need to water more if you live in an arid region.

Cover. Your vegetables will need less water if theyíre shaded under trees, shade cloth, a trellis or other cover. A thick layer of mulch on top of the soil will also help retain moisture.

Related: How Much Do You Actually Have to Water Your Plants?

Testing Your Soilís Moisture Levels

Most vegetable plant roots grow around 6 to 12 inches (15 to 30 centimeters) below ground. You want to make sure thereís moisture at this level of your soil.

The easiest way to check is to stick your finger in the ground as far as it will go. This way you can feel how far down your soil has dried out.

Another good option is to buy a soil probe, which is essentially a long plastic or metal stick with small notches on it that pick up soil when stuck in the ground. This allows you to check moisture at a deeper level in the soil.

You can also use a small shovel to either dig a hole to check moisture, or simply stick the blade in the ground and pull it apart slightly to see the soil below.

Watering Needs of Common Vegetables

Vegetables need water to grow and develop their crops. But, some vegetables can tolerate less water than others.

Itís ideal to group vegetable plants in your garden according to their water needs. If you simply donít have the space for this, you can water everything moderately and spot water the plants with heavier water requirements as needed.

1. High Water Needs

These vegetables are generally the biggest drinkers in the garden. Well-watered plants will produce large, crisp and juicy vegetables. Whereas, limiting water will often have bitter and tough results.

  • Beans and peas
  • Cabbages
  • Cauliflower
  • Celery
  • Lettuce, spinach and other greens

2. Moderate Water Needs

The vegetables below are a bit more resilient. You can usually wait until the soil has dried down 2 to 3 inches (5 to 7 centimeters) before watering again.

  • Artichokes
  • Broccoli
  • Brussels sprouts
  • Celery root
  • Corn
  • Cucumbers
  • Peppers
  • Potatoes
  • Squash and pumpkins
  • Tomatoes

3. Lower Water Needs

These veggies can handle the least amount of water, but they still need a good watering if the soil has dried down to about 4 or 5 inches (10 or 12 centimeters).

  • Beets
  • Carrots
  • Kale
  • Onions
  • Parsnips
  • Rutabagas

Watering Time, Duration and Frequency

Time of day. Early morning is the best time to water because outdoor temperatures are at their lowest. This minimizes evaporation and ensures your plants get the most water possible.

Duration. You want to water long enough for the water to reach at least 6 inches (15 centimeters) down. Check periodically as youíre watering to see how far the water has penetrated and take note of the final time. Deep, periodic watering is better for promoting root development than frequent, shallow irrigation.

Frequency. Vegetables with high water needs generally do best with daily watering, either through rain or irrigation. Moderate-need plants can be watered every second or third day, depending on soil moisture. And low-need plants may be alright three or four days in between watering, unless itís a particularly hot and dry spell.

Related: Which Type of Mulch is Best for Your Garden?

What is the best way to water vegetables?

The most effective irrigation techniques simulate rain. They deliver a slow, steady amount of water over time. Watering too heavily is like a massive downpour, most of the water will pool and run off the soil surface.

Drip irrigation systems are the most efficient because they deliver water slowly and directly to the soil. This gives the soil time to absorb the water and little is lost to evaporation or drift.

Many different configurations of drip irrigation are on the market, such as soaker hoses, drip tape or drip pipes with emitters. Ask your local garden center or irrigation store for advice on finding the best system for your yard.

Top watering is perhaps the most common way of watering vegetables. This includes watering with a hose sprayer, watering can, overhead systems or any other system that applies water overtop your plants.

These methods are typically easier than drip systems because they often need less piping and other infrastructure. Although, there can be an increased risk of water loss from evaporation. And if excess water does not evaporate, fungal disease is more of a threat from water sitting on the leaves.

When possible, all systems work best if you can install automatic timers to control their start and end times. This will ensure your vegetables get the right amount of water at the right times to support an abundant crop.

Related
9 Mistakes to Avoid When Planting a New Vegetable Garden
10 Hot Ideas for a Drought-Resistant Garden
Edible Landscaping: A Delicious Way to Garden

 

 

44 comments

Philippa P
Philippa P28 days ago

Thanks.

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Barbara S
Barbara Sabout a month ago

Thanks

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Stephanie s
Stephanie sabout a month ago

Thank you

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Stephanie s
Stephanie sabout a month ago

Thank you

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Margie F
Margie FOURIE1 months ago

No matter how much I try, I cant get it right

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Susan H
Susan H1 months ago

Thanks

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Carl R
Carl R2 months ago

Thanks Again!!!!

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Rosslyn O
Rosslyn O2 months ago

I built up a composted garden over several years and we have our sink/hand basin water drain into it for added water. Shade cloth is a must due to only having 3 months of Wet season and the other 9 dry and hot to very hot with no humidity. It is a massive challenge most years, sadly the last 5 have been drought so nothing was planted as we have had to purchase water for ourselves and the animals. So we just keep composting and hope this wet will shape up to be a good one. Thanks very much for the guide on water needed for the differing plants. Very helpful.

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Carl R
Carl R2 months ago

Thanks!!!

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heather g
heather g2 months ago

Regular strong winds dry our garden plots quickly. I'll remember that kale doesn't need much watering.... mine went to seed within weeks, anyway.

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