Watering plants in hot weather

Surviving a Heat Wave: 6 Hot Weather Watering Tips

This post is in partnership with Gilmour Garden and Watering. All thoughts and words are my own.

It’s here — the dog days of summer. Or should I say, it’s been here, as we’ve been feelin’ the heat for the past few weeks with seemingly no end in sight.

My Southern California garden is accustomed to the sultry weather this time of year, but it’s not any easier on the plants than it is on me. We have a full south-facing garden and September is generally the hottest month for us coastal dwellers, when Santa Ana winds blow in from the desert and bring extremely dry, hot and dusty winds that amplify an already dry season.

Keeping the garden cool and well-watered is key to helping plants survive the sweltering weather. Even with drip irrigation installed in my garden, I find that I still need to supplement with hand watering during our drought and heat spells.

I keep a few sets of Gilmour’s Flexogen Super Duty Hoses paired with their Heavy Duty Thumb Control Watering Nozzles in different parts of the yard, and have been using them for the past year to water our containers and hard-to-reach corners.

Having tested all types of nozzles over the years, I’ve discovered that I really like having a thumb control. The water turns on and stays on, without me needing to squeeze a trigger — no more achy hand after a day in the garden!

It’s almost life-changing when you’re someone who spends a considerable amount of time outside (and I’ve actually started replacing all my trigger squeeze nozzles with this thumb control model). I can easily adjust the water flow with my thumb as I move from plant to plant, and I’m always a fan of pattern nozzles, which offer so much more versatility than a standard spray nozzle.

As for the hose, well, it’s a hose — it works, it’s relatively lightweight, and so far it’s burly enough to take some abuse in the garden. (I am definitely not one to be gentle on my gardening gear!) The thickness of the material also seems to help keep the hose from kinking.

But the thing I like most about it is actually the neutral gray color and glossy coating. While this may sound superficial, the color and coating resists dirt very well — a huge plus in my book. I have some lighter-colored hoses, and a slight annoyance with them is the fact that they seem to grab onto every speck of dirt and look really grubby pretty fast. (I use and abuse my hoses, remember?)

I guess some people would prefer function over form, but putting my hands on a grimy hose deflates the fun of watering a bit (which, for me, is already more a chore than a meditation). So if a hose can stay clean and sharp-looking as well as get the job done, I’m all for it.

To help your plants switch to summer survival mode — while being mindful of our limited resources — I’ve partnered with Gilmour to bring you my top six tips for hot weather watering.

1. Time your watering for the morning or late afternoon.

The best time to water your garden is from 6 am to 10 am — before the heat of the day sets in, giving your plants plenty of time to drink up and any moisture on the leaves to dry off before nightfall. If that isn’t possible, the next best time is from 4 pm to 7 pm.

Unless you live in an arid climate, try to avoid watering at night, as cool and wet conditions could encourage fungi and bacteria, slugs and snails, sow bugs, earwigs, and other pests into your garden.

But all told, don’t worry if all you can do is a midday watering — any water is better than none at all, and the oft-repeated belief that watering on a hot sunny day will damage your plants is a gardening myth that’s been debunked by science.

Sunburn (which often appear as bleached areas on the foliage of young transplants, heat-sensitive plants, and distressed, underwatered plants) is caused by simple overexposure to the sun, not by water droplets that supposedly magnify the sun and scorch the leaves. There are good reasons for not watering in the middle of the day under a blazing hot sun, but leaf scorch is not one of them.

In the morning, the air and soil are cooler, which minimizes evaporation. The lack of wind means you avoid wasting water to wind drift. And most importantly, plants absorb water more readily when they’re not under heat stress — a condition that’s more likely to occur when the sun is at its peak.

2. Water well and water deeply.

Just like people, plants need thorough hydration during times of excess heat. This is especially true of outdoor container plants, as well as new plantings that haven’t yet established their roots.

Container plants — particularly those in smaller pots, clay pots, and baskets lined with coco fibers or sphagnum peat moss — are more susceptible to drying out than their in-ground counterparts. In the height of summer, these potted plants need special attention and may require watering every day or even twice a day.

A good rule of thumb is to water when the first 2 inches of potting soil feels dry. The smaller your container, the more you’ll have to water it.

Both annual and perennial plants in the ground benefit from a good deep soaking up to three times a week. Allowing the water to penetrate slowly and fully into the soil (to a depth of at least 6 inches) encourages roots to grow deeper and stronger and protects them from the hot soil surface.

Remember: Infrequent deep soakings are better than frequent light sprinklings. Aim the water right where it’s needed — at the root zone of your plants — to reduce the chances of runoff and evaporation.

During periods of extremely dry, hot weather, I also like to give my plants (especially the more fragile or heat-sensitive ones) a gentle overhead shower with the “garden” setting on Gilmour’s thumb control watering nozzle (a full, consistent spray similar to a soft rain).

From a conservation standpoint, it’s not the most economical use of water, but there are times when it’s called for to promote a healthy garden. In dry, windy weather, a fine layer of dust can build up on your plants and reduce their ability to photosynthesize efficiently.

Heat-stressed plants are also more prone to pests like aphids, which can naturally be controlled by a sharp blast of water. (I like the “jet” setting on the nozzle for this purpose.) And finally, a quick, cooling shower can offer relief to a drooping plant, as it helps lower leaf temperature and prevent heat stress.

3. Promote high humidity.

Plants that like it humid, such as ferns, ginger, hibiscus, and elephant ears, should be misted frequently during periods of dry, hot weather. The “flower” or “soft wash” settings on the nozzle are perfect for delivering a delicate, uniform spray of water to these moisture-loving plants.

If it’s particularly breezy, you may need to mist them a couple times a day and give the garden a second watering in the late afternoon to increase humidity.

4. Shield heat-sensitive plants from excessive sun.

A heat wave is hardest on new transplants that haven’t had time to develop a strong root system (including drought-tolerant transplants, which — contrary to popular belief — still need regular watering for the first year or two while they get established).

If your plants are in containers, move them to an area of the yard that’s partially shaded in the afternoon. Transplants that need to go in the ground sooner than later should be hardened off first, then planted in the garden where they get only dappled light or afternoon shade.

(Quick tip: Grow them next to taller annuals or deciduous perennials that offer some cover. By the time the new plants establish roots and require full sun, those taller plants will have died back.)

Other plants in the ground can be protected by shade cloth or row cover, which still lets in light and water but blocks a specific amount of sun (called a “shade factor”) from 25 percent to 90 percent, depending on its configuration.

In a pinch, even a white (or light-colored) bed sheet strung across your garden bed or draped over your plant cages will work. The sheet lets in all the warmth and light of the day while shading your plants and reflecting light off of them at the same time.

5. Don’t fertilize during a heat wave.

Very high soil temperatures (above 85°F) can cause plants to go semi-dormant, so they use very few nutrients while they’re in survival mode and aren’t prepared to make use of them. Withhold the fertilizers (or apply a weaker diluted solution) until the weather cools off a bit and your plants have a chance to recover.

When I need to give my plants a nutritional boost in high summer, I make sure the soil is evenly moist first (to reduce heat stress and improve absorption) and use a half-strength organic liquid fertilizer right at the root zone. My go-to liquid feed is this fish emulsion, which I’ve been using all over my vegetable garden for years.

6. Keep as much moisture in the ground as possible.

This really should be the number-one tip, but I hope that adding it last ensures you won’t forget it!

An organic mulch like shredded bark, wood chips, or straw (not hay — you don’t want to introduce all those weed seeds to your garden) conserves moisture, smothers weeds, regulates soil temperature to keep plant roots cool in summer, and adds small amounts of nutrients to the soil through decomposition.

It also prevents soil (and whatever fungi and bacteria are lingering in the ground) from splashing up on the leaves while watering, which reduces the spread of disease.

A minimum 2- to 3-inch layer of mulch should be added on top of the soil, taking care not to pile it up around the base of your plants (as it can hold too much moisture against the stems and lead to rotting). Replenish the mulch as needed throughout the year.

During intensely hot weather, don’t be afraid to layer it on thick — up to 4 inches if needed to shade the soil from heat and sun.

Brought to you by Gilmour Garden and Watering. Thank you for supporting the brands that support Garden Betty.

Gardening Sources

Gilmour Flexogen Super Duty Garden Hose | Gilmour Super Duty Stainless Steel Thumb Control Nozzle | Bloem Easy Pour Watering Can | Neptune’s Harvest Hydrolyzed Fish Fertilizer

Beautify Your Garden with These Flower Watering Tips

We all grow up knowing plants need soil, sunlight and water, but we often don’t realize the importance of consistently watering flowers. A lack of moisture can cause a flower garden to wilt and produce very few – if any – blooms. Overwatering flowers can cause disease and the drowning of plants. Whether you have annuals, perennials or flowering shrubs, knowing the best way to water these plants is key to a showy abundance of blooms that will be the envy of the neighborhood.

Watering Flowers

  1. Help New Plants Establish
    Both young seedlings and young plant transplants are very susceptible to stress. To give them consistent growth and a healthy start, gently mist the soil with Gilmour’s Classic Rear Control Nozzle to add moisture before seeding or transplanting. Water daily for the first week to keep the soil moist, but not soggy. After seven days, you can cut back to watering the flowers just a few times per week to encourage deep root growth.
  2. Give the Roots Water
    While roses and other flowers look pretty with water droplets glistening in the sun, wet foliage does nothing good for plants. Use a soaker hose to place the water exactly where it’s needed – on the soil. In doing so, you reduce evaporation, conserve water and decrease the potential of disease. Simply place the hose at the base of your plants and cover with mulch.
  3. Mulch Well
    Mulch helps soil absorb water and maintain a constant level of moisture. Apply approximately 3 inches of organic mulch evenly throughout your flower beds. Avoid placing mulch within 2 inches of the base of flowers and shrubs. Too much mulch against plants can encourage disease and become a home to damaging pests.

How Often Should You Water Flowers

Resist the urge to give flower gardens a little drink whenever you feel like it. Flower gardens require only 1 inch of water each week (including rainfall). Learn how often you should water flowers in your garden by looking at the soil. For fast draining soil, a ½ inch of water over two sessions is a good rule of thumb. Heavier clay soils perform well with one watering session per week.

Wondering when to water flowers? The best time to water flowers is in the morning between the hours of 6-10 a.m. The cooler weather reduces evaporation and helps the water stay where you need it – with the plant.

Am I Overwatering My Flowers?

It can be hard to determine how much water your garden is getting. You may be unsure about the output of a garden nozzle or sprinkler.

Placing a rain gauge in your garden will help keep track of how much water the garden is getting each week. Don’t have a rain gauge? No problem – a straight-sided container and a ruler can give you the same information. Use it to keep track of rainfall and to determine the output of your sprinklers and nozzles.

Knowing when to water flowers in hot weather or times of drought can be tricky. If you feel your flowers aren’t getting enough moisture, check the top 3 inches of soil. It should be consistently moist. You may need to increase your watering schedule to maintain moisture.

What Tools Do I Need to Water Flowers?

  • Water Hose – Essential for getting water from the faucet to your garden, Gilmour’s multipurpose garden hoses are built to last season after season.
  • Nozzle – A spray nozzle allows you to direct water to the base of individual plants. Different types of spray nozzles allow for individual control the way you like it.
  • Watering Wand – A watering wand delivers a gentle spray without stooping or bending. Easily get between lush greenery or add a bit of moisture to hanging plants and container gardens with ease.
  • Soaker Hose – Gilmour’s soaker hose allows you to directly water your soil and deliver moisture efficiently. Place the hose under mulch to maintain a beautiful garden.
  • Sprinklers – Flower bed sprinklers rain gentle moisture onto your plants. Ideal for establishing new flower beds and less crowded areas, an elevated sprinkler is attractive without distracting from your blooms.
  • Programmable Timer – A programmable timer allows you to set a watering schedule and focus on more important gardening tasks. Automatic flower watering lets you simply set the time and the length of watering. A handy rain delay automatically skips watering if nature took care of it for you.

When you know how to water flowers, your blooms will multiply and make it a Betterday!

A guide to watering in extreme heat

This summer’s relentless heat has posed challenges to gardeners and their plants. Everything dries out faster when it’s hot: flowers and vegetables, whether in a garden or in containers, young trees and shrubs, and lawns from small urban yards to large suburban spreads.

Repeated wilting and re-hydrating is detrimental to most plants, so one of the biggest challenges is trying to maintain a relatively steady supply of moisture to the soil. This is not just to keep plants looking their best (though it does that) but also to promote continued healthy growth and help plants cope with the stress of summer diseases and insects.

While some herbs (marjoram, oregano and rosemary, for instance) thrive and develop their most intense flavor when grown under hot, dry conditions, many vegetables are negatively affected by heat coupled with wide moisture swings. Cucumbers may be misshapen and bitter-tasting. Potatoes may be knobby, and can develop green areas that are mildly toxic when sunlight penetrates through the cracks of hard, dry soil. (Peel off those green areas before you cook the potatoes.)

Tomatoes frequently develop blossom end rot, a dark, leathery splotch that begins where the flower was attached, and enlarges as the fruit grows. (You can slice off that part of the tomato and use the rest, but you’ll lose a sizable chunk of each fruit, and you’ll need to use it right away.) The dark area is caused by a lack of calcium available to the developing fruit, primarily from an interruption in moisture uptake.

Adding calcium to the soil usually doesn’t solve the problem. Instead, focus on maintaining constant moisture levels. Mulch around tomato plants in the garden so you don’t have to hoe weeds, potentially severing tomato roots in the process. Water deeply, but don’t wait until the soil is bone dry to water again. If your tomato is in a large container, you may have to water more than once a day during the worst heat.

Any plants — flowers, herbs or vegetables — growing in containers will dry more rapidly than if they were in the ground. How often you water will depend both on the size of the container and what you are growing. But frequent watering poses a problem, too: It leaches nutrients through the soil.

If you incorporated timed-release fertilizer pellets into the soil, the plants might be fine — at least for most of the summer — because every time you water, a bit of fertilizer is released. Otherwise, make a point of fertilizing more frequently than you normally would — every week or two, using fertilizer dissolved in water. Don’t fertilize when the soil is dry, though. That’s a recipe for burning the plant’s roots.

Spread several inches of mulch in the garden and around young trees and shrubs to help insulate the soil, keeping roots from getting too hot and dry. This also cuts down on surface evaporation of moisture from the soil. Set your hose to trickle slowly at the base of young trees and shrubs every few days during hot dry weather, to thoroughly soak their roots.

Water gardens early in the day when it’s cooler and less windy. Watering in the heat of the day shouldn’t hurt the plants — it actually cools them off — but it’s a far less efficient use of water as much of it will evaporate before reaching the roots. Avoid getting plants wet late in the day unless it’s the only possible time you can water them. If they don’t dry before sundown they’ll stay wet all night and be more prone to fungal and bacterial diseases.

Water lawns thoroughly once a week or perhaps a little more frequently in extreme heat, to yield deeper roots and healthier grass. Sometimes irrigation systems are set to water a relatively short period daily or every other day. Light watering, however, encourages shallow root growth, which leaves the grass more vulnerable to heat and drought damage, particularly if you’re unable to faithfully maintain a frequent watering schedule. (This is a real possibility as municipalities often declare water restrictions in late summer.)

Don’t fertilize the lawn or spray herbicides when temperatures are high. The potential for damaging the lawn is too great. Hold off fertilizing until September, when nights are longer and temperatures moderate. If you must get rid of weeds this time of year, dig them out manually. Unfortunately, the heavy rains we had earlier interfered with the efficacy of pre-emergent herbicides and as a result, we have a bumper crop of crabgrass. These plants are annuals and will die this winter, but their seeds will fall to the ground and sprout next spring.

Deb Brown is a garden writer and former extension horticulturist with the University of Minnesota.

Try these tips for watering

Water your vegetables two to three times a week during really hot weather. Watering the garden deeply is critical. The water must go down, down, down to encourage deep roots and get away from the hot soil surface. Put a little cup or can in the garden soil and don’t stop watering until it has collected at least an inch of water from the sprinkler that you set up. (If your veggies are in containers, they’ll probably need water every day or so during the heat because containers tend to dry out faster than the ground.) If you aren’t using a sprinkler, put the cup under your drip or soaker hose. It won’t be quite as accurate, but it’s better than nothing. To hand-water a small plot, or pots, use a nozzle turned to the “shower” setting for gentle, rain-like watering. If water puddles on the surface at first, move on, but come back several times to be sure the water is soaking in and the soil is thoroughly moist.

Watch your garden for an “indicator” plant, which is the first plant to wilt as the garden becomes dry. You’ll always know to water when that particular plant has droopy leaves. The first is usually a squash, cucumber, or melon because the big leaves lose lots of moisture fast. Of course, it’s better to water consistently so that this “indication” never happens, but it’s not a perfect world and even the best of gardeners gets caught by wilting plants. Know too that in very hot, dry, and sunny weather, the big-leafed plants will wilt a little in mid-day no matter what, but they should recover quickly in the evening.

Avoid wetting plant leaves when you can. Of course, if you use a sprinkler, it is impossible not to wet the leaves when watering the garden, so in that case, water early in the morning so that the foliage will dry early and quickly to minimize disease risk. You can put the sprinkler on a timer so that it comes on just before daybreak, when the leaves may already be wet with dew. The gardening principle here is to avoid adding to the length of time that the leaves stay wet because many diseases need moisture to thrive.

Do what you can to keep water in the ground. An organic mulch such as wheat straw, finely ground bark, pine needles, or chopped-up leaves spread on the ground around and under plants is a welcome barrier between the moist soil and the hot sun. A 2- to 3-inch layer of mulch makes a huge difference in hot weather, acting as a shade cloth to hold in moisture and cool plant roots. Without mulch, the intense sun bakes the soil — and you end up watering the garden even more.

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