Miniature Gardening in Extreme Heat

<~ This umbrella trick worked out well for our recent heat wave here in Seattle. Our big, in-ground miniature garden can normally tolerate the full sun but, with the extreme heat this week, we knew the newly-planted trees just weren’t used to it and nor were they established enough. It takes at least one full year to be fully confident that the trees and shrubs are established in the ground. (Some say it takes at least one full season for a plant to get established, but they never clarify which season it is.)

In extreme heat, besides the risk of getting scorched by the hotter sun, the ground might dry out too often and too fast, which puts undue stress on the plants. So, by placing an old market umbrella to shade our miniature garden from mid-morning to late afternoon sun, it will give the conifers a break. And by taking the umbrella off in the late afternoon and replacing again it the next morning while the temperatures were in the triple digits, it worked like a charm.

You can also use this trick for new mid-season plantings if you’re in a climate where the weather will let you do this.

I’m not sure I’d recommend planting anything for in the southern states in the middle of summer but, by using the umbrella trick and sheltering the planting from the extreme sun, you can might be able to get away with planting in-ground in the summertime if you are able to acclimatize the plants gradually to their new home. The idea is to mimic spring, or fall, weather by shading the new plantings from the midday to late afternoon sun. Again, take the umbrella off in late afternoon, and replace it mid morning so the plants can get some light. Note that this example is for full sun plants. (I tested this method with a fully-grown tomato plant one July and it worked out well with careful monitoring. The umbrella fit right on the tomato cage so it turned out to be easier to do than expected. So if I can make this work when transplanted a mature vegetable plant mid-season, I know it works.)

And when watering your new plantings, keep on top of it – but don’t over-water. Follow the watering schedule for the plants and let them dry out to just barely damp between watering sessions to avoid drowning the plant – even in extreme heat. 

Containers, of course, can be done anytime! Again, be conscious of that hot, late afternoon sun, as the pot will dry out too often and stress out your plants.

10 Watering Tips Help Your Garden Beat the Heat

Here are some tips for keeping your miniature garden, and your full-sized garden, healthy during heat waves. You may be in an area with a water ban as well so it is even more critical to conserve whatever water you can. With proper watering techniques, you can get the most out of your watering even in extreme temperatures.

The following tips can work for containers or for the garden bed.

1. Test: Only water if needed. Stick your finger down into the soil at least an inch deep. If it is still moist or damp, you can put off the watering for a day or so. If it’s dry, then water. For smaller pots, lift them up to feel how heavy, or light, they are. Dry soil will be much lighter than moist soil.

4. What to water: Water the soil, not the plant, and make sure the water gets down to the roots.

7. Mulch: Mulching means to put a 2″ to 5″ layer of (usually) organic matter on top of the soil to help keep the moisture from evaporating. Organic mulch can be bark, wood chips, straw, cocoa beans, pine needles, shredded leaves, compost or cut grass. Inorganic mulch can be a variety of things like rubber chips, newspaper, or plastic. For your miniature garden, use a fine compost and keep the layer even throughout the garden bed. For pots, the fine compost works well too, but normally you wouldn’t have much bare soil in a container.

2. Frequency: Water your in ground gardens deeply and infrequently. This will teach the roots of the plants to look for water on their own, and grow deeper into the soil. Watch your watering for your containers and water accordingly for the plants’ needs, not just because it is a new day.


8. Cover the ground: Some of our most favorite miniature garden plants are ground covers fortunately. By covering the bare ground with plants and foliage, it will slow down the soil drying out.

10. Plant more: It is too late to plant anything new during a heat wave but this fall, consider planting more of your full-size garden. Big trees bring shade, combined with big shrubs can create an naturally cool place in your garden. Planting in fall is one of the best times to get a garden established before next summer, and you’ll use less water next summer, because the winter rains and snow will help them get established in their new home.

5. What to use: Conserve water by hand watering. Sprinklers and sprays of water don’t direct the water straight to the plant’s roots where it is needed. Use a watering wand on the shower setting, and turn the tap on half-way to avoid strong, misdirected sprays of water that is just going to evaporate in the heat.

9. Shade: Is your miniature garden in a container? Move it out of the full sun into a bright shade spot, the north or east side of the house. Even if the plants belong in full sun, they’ll be okay for a few days on the porch or awning until the heatwave passes. If you have new plantings in ground, use a big golf umbrella to shade them during the hottest hours. Weigh-down the handle of the umbrella so it won’t blow away.

3. Timing: Water in the early morning or, better yet, at night after the sun has gone off your garden. The plants can recover during the cooler nighttime temperatures. Watering mid-day is useless – most of the water will evaporate quickly.

6. Corral the water: Build a trough around the base of your plants to direct the water straight down to the roots. Fill up the trough with water and let it drain down a couple of times for some deep watering. This is a critical technique if your garden is planted on a hill.

Water ban? When you turn on your shower, or your tap, and wait for the water to get hot, collect the water (called grey water) in a bucket to bring out and water the garden. Better yet, plug the drain and collect your all shower water – if you take baths, use the bath water. Make a scoop by cutting out the bottom of a square milk jug or detergent container. You can also put a bucket in every sink to collect the run off every time you turn on any tap. Consider using organic soaps although I’m not sure if it does matter because this is not recommended for edible crops. You can also use the water that you boil any vegetables in too. Note that some areas have certain regulations for grey water usage.

More on Efficient Watering Practices

Notes on using your water and your time efficiently.

  • To get a plant established it needs regular watering for at least a year. Drought-tolerant plants like mugo pine trees and juniper bushes will need nurturing until their roots grow in and can find water on their own. Drought tolerant doesn’t mean the plant will never need water, if your area is having a dry spell, it will need some water.
  • Watering infrequently but deeply and thoroughly will encourage rooting and greater tolerance to drought conditions because plants send out extra roots to seek water.
  • To get a plant established it needs regular watering for at least a year. Drought-tolerant plants like mugo pine trees and juniper bushes will need nurturing until their roots grow in and can find water on their own. Drought tolerant doesn’t mean the plant will never need water, if your area is having a dry spell, it will need some water.
  • Mulching cuts down on water loss due to evaporation but, in the miniature garden, most mulches are just too chunky and throw the scale off. We mulch with good layer of compost in the springtime and then anytime our next compost batch is ready, we rotate through the garden beds and mulch wherever it is needed. A 2-inch layer of mulch or compost is recommended.
  • Water infrequently, but deeply and thoroughly. This will encourage rooting and greater tolerance to dry spells. Plants send out extra roots in dry conditions to seek water. As a side benefit, plants often bloom more profusely when stressed, as the natural instinct to reproduce creates more flowers.
  • Shelter containers to help conserve water by moving containers to areas with partial shade to keep the container from heating up and the soil from drying out too quickly and too often in hot, windy areas.
  • Grouping containers together helps to slow-down the water evaporation too.
  • Install a water-conserving irrigation system if you can. Slow drip and deep root watering systems can save up to 60% of all water used in the garden.
  • A simple soaker hose can be dug into the bed before or during planting will help tremendously – especially during the hot summer nights, you can cool down your garden and enjoy the smell and feel of the moisture in the air. Use a garden hose splitter (pictured left) so one end connects to the soaker hose, and the other can stay as your regular hose. The splitter will let you turn on one side at a time, or both together.
  • For new beds that need consistent water until they are established, put the soaker hose on a timer to turn on early in the morning for a half hour or more. The duration is dependent upon the soil, sun and air temperature. Your goal is to let the soil dry out until it is barely damp in between watering sessions. The photo at left shows the timer is placed to turn on two hoses by using a hose splitter.
  • Use correct watering techniques like watering early in the day, especially as the weather warms up, to reduce evaporation loss. Water less often but longer to encourage deep root growth. If drip irrigation won’t work for you, try a hand-held soaker hose rather than a sprinkler.
  • Water responsibly. If you use a sprinkler, make sure you don’t water sidewalks or driveways.
  • Be sure your irrigation system is in proper working condition.
  • Discourage water competition from weeds by keeping the weeds pulled, pull the root and reduce the likelihood of them returning by mulching.
  • Thinking of using landscaping fabric? The weeds will still populate on top of the fabric but their roots will grow into it. When you pull that weed, you’ll pull the fabric and upset the entire area. I’m not a fan of it nor I recommend it. In our garden, the previous owner used it under the shrubs on all side of the house and it is now a hassle to deal with.

How to Save Your Trees – Accidental Drought & How to Recover


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