Tag Archives: watering advice

Design trends

Watering Tips for Hot Weather

De la Mina verbena is a California native that blooms spring to fall. Water when the top 3 inches of soil is dry.

After a lovely, mild spring, summer weather arrived with a vengeance. My poor plants were thinking they lived in England and then were rudely awakened and reminded that they actually live inland and away from the influence of the cool coast. My watering schedule and methods have changed and I’m reminded of some tips that will make all the difference in my plants’ performance this summer.

After you’ve chosen climate adapted plants how much water do they really need? Here’s how can you keep everything happy and not waste water.

All plants need water- even those that are tolerant of our summer dry conditions. Water makes up 90-98% of every plant we grow. It’s needed for photosynthesis, as well as reproduction and defense against pests.

With summer water bills arriving this is a good time to re-visit how often and how much to water that landscape you’ve spent so much money to create. Basically, you’re wasting water if you’re not watering deep enough to moisten the entire root ball or if you’re irrigating too often.

Photosynthesis is one of the most remarkable biochemical processes on earth and allows plants to use sunlight to make food from water and carbon dioxide. At temperatures about 104 degrees, however, the enzymes that carry out photosynthesis lose their shape and functionality. A garden that provides optimum light and water but gets too hot will be less vigorous.

Plants have natural systems that respond to heat problems. Plants can cool themselves by pumping water out through the leaves for a kind of swamp cooler effect. They can also make “heat-shock” proteins which reduces problems from over heating. All these strategies can take resources away from a plant’s other needs like growth, flowering and fruiting.

So how much water do different types of plants need during the heat of summer?

Be sure that you water trees and shrubs deeply, checking soil moisture first with a trowel. Established small to medium shrubs should be watered when the top 3-6 inches of soil is dry. Water large shrubs and trees when the top 6-12 inches is dry.

As a rule of thumb, trees and large shrubs need deep but infrequent watering. They should be on a separate valve than your smaller shrubs and perennials. Water ornamental trees 1-3 times per month depending on the type and soil. Tree roots grow 12-36 inches deep and require 10 gallons of water per inch of trunk diameter.

Apply water with a soaker hose, drip system emitters or hand held hose with shut off and soft spray attachment according to your water district’s restrictions. Don’t dig holes in the ground in an effort to water deeply. This dries out roots even more. Be sure to water the root zone to the indicated root depth every time you water. Watering deeper than the root zone only means you are wasting water. You can test how deep you watered by pushing a thin, smooth rod into the ground soon after you irrigate. The soil probe should easily slide through the wet soil but become difficult to push when reaching dry soil.

The roots of smaller shrubs reach 12-24 inches deep in the soil. Established native shrubs may need only monthly waterings to keep them looking their best while other shrubs may need watering every 7-10 days during the heat of the summer. Perennial roots only go down 12 inches or so and may need watering once or twice a week depending on type.

When is the best time to water? Watering in the morning is the most efficient whether you water by sprinkler, drip system, soaker hose or by hand because the water soaks deep in the soil without risk of evaporation. This bolsters the plant for the day and has dried from leaves by evening reducing the risk for foliar diseases like mildew. Plant roots are also more receptive to watering in the morning. Don’t forget your pots. On a hot day, you can water midday to not only supply moisture but to cool the soil. You wouldn’t want to live in a pot where the temperature at the roots could reach over a hundred either.

Is it true that water droplets will scorch leaves in the midday sun? According to a study, fuzzy-leaved plants hold water droplets above the leaf surface and act as a magnifying glass to the light beaming through them so there is a very slight chance of scorch.The study also reported that water droplets on smooth leaves, such as maples, cannot cause leaf burn, regardless of the time of day. But no matter the time of day, a plant that needs water should get the right amount.

Butterfly Bush are fragrant, too.

It’s no surprise that many California natives are adapted to high temperatures. Some California native plants that can handle the heat with little water include salvia, mimulus, California fuchsia, eriogonum, manzanita, artemisia, California milkweed, ceanothus, mountain mahogany, bush poppy, bush lupine, native penstemon, monardella, mahonia nevinii, fremontodendron and holly-leafed cherry.

Other well adapted plants that are known to be more tolerant of heat include butterfly bush, germander, rosemary, smoke tree, rudbeckia, coreopsis, lantana, plumbago, gaillardia, lilac, sedums, oregano and verbena.

With lots of mulch and the above watering tips you can keep all your plants happy and healthy.

Design trends

Watering: Making Every Drop Count

Fremontodendron – a low water use Ca. native

File this under the heading “Be careful what you wish for.” The Dog Days of Summer aren’t even here yet but the thermometer is inching toward 100 degrees. How’s your garden looking?

All plants need water– even those that are tolerant of our summer dry conditions. Water makes up 90-98% of every plant we grow. It’s needed for photosynthesis, as well as reproduction and defense against pests.

What happens to a plant when the thermometer tops 100 degrees? Are there some plants that can survive tough times more easily?

Photosynthesis is one of the most remarkable biochemical processes on earth and allows plants to use sunlight to make food from water and carbon dioxide. At temperatures about 104 degrees, however, the enzymes that carry out photosynthesis lose their shape and functionality. A garden that provides optimum light and water but gets too hot will be less vigorous. Tomatoes, for example, will drop blossoms and not set fruit if temperatures are over 90 degrees. Plants that do endure hight heat may be stunted and weakened attracting pests and diseases even if water is available.

Plants have natural systems that respond to heat problems. Plants can cool themselves by pumping water out through the leaves for a kind of swamp cooler effect. They can also make “heat-shock” proteins which reduces problems from over heating. All these strategies can take resources away from a plants other needs like growth, flowering and fruiting.

Mimulus aurantiacus

It’s no surprise that many California natives are adapted to high temperatures. Some California native plants that can handle the heat with little water include salvia, mimulus, California fuchsia, eriogonum, manzanita, artemisia, California milkweed, ceanothus, mountain mahogany, bush poppy, bush lupine, native penstemon, monardella, mahonia nevinii, fremontodendron and holly-leafed cherry.

California fuchsia

Other well adapted plants that are known to be more tolerant of heat include leucadendron, butterfly bush, germander, rosemary, smoke tree, rudbeckia, coreopsis, lantana, plumbago, gaillardia, lilac, sedums, oregano and verbena.

So how much water do different types of plants need during the heat of summer?

Be sure that you water trees and shrubs deeply checking soil moisture first with a trowel. Established small to medium shrubs should be watered when the top 3-6 inches is dry, large shrubs and trees when the top 6-12 inches is dry.

As a rule of thumb, trees and large shrubs need deep but infrequent irrigation. They should be on a separate valve than your smaller shrubs and perennials. Water ornamental trees 1-3 times per month depending on the type and soil. Tree roots grow 12-36 inches deep and require 10 gallons of water per inch of trunk diameter.

Safari Sunset leaucadendron

Apply water with a soaker hose, drip system emitters or hand held hose with shut off and soft spray attachment according to your water district’s restrictions. Don’t dig holes in the ground in an effort to water deeply. This dries out roots even more. Be sure to water the root zone to the indicated root depth every time you water. Watering deeper than the root zone only means you are wasting water. You can test how deep you watered by pushing a smooth rod that’s 1/4 inch – 3/8 inch in diameter into the ground soon after you irrigate. The soil probe should easily slide through the wet soil but become difficult to push when reaching dry soil.

The roots of smaller shrubs are 12-24 inches deep in the soil. Established native shrubs may need only monthly watering to keep them looking their best while other shrubs may need watering every 7-10 days during the heat of the summer. Perennial roots only go down 12 inches or so and may need watering once or twice a week depending on type.

With lots of mulch and the above watering tips you can keep all your plants happy and healthy

Design trends

Rethink the Lawn & Save $

This garden sitting area looks inviting after the old lawn was removed.

Water is a precious and vital resource. Our bodies are about 60% water and our brain – a whopping 70%. Less than 1% of the water on the Earth, however, is suitable for human consumption. With the population increasing and the water supply staying the same, water conservation indoors and out is important. A well planned landscape makes water conservation outside the home even easier. Since up to 70% of summer water use comes from landscape irrigation it’s a good place to start.

Both San Lorenzo Valley Water – http://www.slvwd.com – and Scotts Valley Water Districts – http://www.svwd.org – offer many tips and incentives to conserve water. Scotts Valley Water District is even having a limited time offer to double your Lawn/Turf Replacement Rebate from $1 to $2 per square foot when replacing with low water-use alternatives. All sites must have a pre and post inspection completed my June 30, 2021 so don’t miss out on this great opportunity. You can apply on their website by requesting a pre-inspection lawn measurement before April 15th.

The fun part begins when you redesign the area where you took out the lawn or modify the plantings in other beds to include same water use plants. It doesn’t make much sense if you have some plants that require more water than others in the same bed. You have to water to the highest water-use plant to keep everybody happy.

Hydrozoning is the practice of clustering together plants with similar water requirements to conserve water. A planting design where plants are grouped by water needs improves efficiency and plant health by avoiding overwatering or underwatering. And as you move farther away from the water source your plantings should require less water.

An edible garden replaced the old lawn.

When redesigning your landscape start with simple things. Rock, stone, and permeable paths and driveways add visual interest to the landscape and don’t require irrigation. Improving your property’s soil quality aids in saving water regardless of the plants grown there. Organic materials added to the soil help establish a strong root system for plants. Nutrients in the soil allow the plants to become stronger, too. Adding a layer of mulch increases the plant’s efficiency by retaining moisture and keeping the soil temperature stable.

Choose the right plants for your location. California natives or plants from similar climates in the world are low maintenance, low irrigation plants and usually need less tending, fertilizer and pruning. Your choice of groundcover can make a big difference, too, in how much water the landscape saves. Keeping grass areas to a bare minimum reduces the amount of water needed to keep the landscape looking green and fire safe.

Your method or irrigation helps conserve water. Hand watering where possible, especially new plantings, directs the water exactly where it needs to go and you can shut off the hose as soon as the plants receive enough water. A soaker hose is another efficient option that reduces evaporation during the watering process. An automatic irrigation system with a rain sensor, weather based controller or soil moisture sensors is the newest way to save water.

There are lists of drought-tolerant plants and water smart grasses, as well as replacing lawns with drought tolerant or native plants on the Scotts Valley Water District website. Permeable landscape materials such as mulch, decomposed granite, permeable pavers are other ways you can keep your yard looking beautiful and also be water efficient.

Now is the time before it gets hot to look at your irrigation system, plant choices and rebate options to save water and money and recharge our aquifers.