Watering Plants in the Palm Beach Landscape
It is time for a new approach – we need a way of creating beauty in our landscape without wasting water, harming our environment, or ruining our backs with maintenance.For generations, the Palm Beach landscape has been blessed with an abundant water supply – as much as we could possibly want for landscape irrigation. Because of this abundance, we were never concerned about how much we watered. Overwatering results in shorter life-spans, more disease, more maintenance and increases the need for fertilizer. With rapid population growth and a simultaneous loss of wetlands to store our water, we are now facing water restrictions every few years in the Palm Beach area.
Overwatering is the gravest error gardeners commit in the Palm Beach landscape. This common practice shortens a plant’s life, causes disease, and increases the maintenance requirements of each plant. The plant grows faster with more water and, therefore, needs more trimming. The growth is often leggy because the plant is frantically trying to figure out where to store all this water; thus, long, loppy stems result. Overwatered plants also require more fertilizer than properly watered plants because the water washes the fertilizer through the soil.
Overwatering stresses our environment when we have droughts. In severe droughts, water is diverted from wildlife areas to satisfy plants that do not really need it. It is time for a change.
My research has centered on plants that don’t require water more than twice a week. Some require water only once a week.
Recently-planted shrubs, trees and groundcovers in the Palm Beach landscape need frequent, deep watering to establish their roots in the ground. The watering schedule depends upon the plants’ environment. Shade gardens require half the water of sun gardens. Windy gardens require more water than calm gardens. Plants require twice as much water in summer heat than in winter cool. If it sounds confusing, remember that your plants will tell you when they need water by wilting.
Once I had a call from a customer who told me that his recently planted landscape was dying. I went to his house and saw a garden dying of thirst. He told me it couldn’t be thirst because it had rained that morning. It had sprinkled just a little. Imagine that you are very thirsty, and someone gives you a thimble filled with water. It is not enough, and you remain thirsty. Newly planted material needs enough water to soak the entire root ball with each application. It takes about one inch of water to soak the soil to a depth of one foot. Put several empty coffee cans in your garden and see how long your sprinklers need to run to fill them to a depth of one inch. Every time you run your sprinklers, apply one inch of water. Watering to this depth gives adequate water to most plants that were grown in containers in a nursery.
Field-grown trees present another problem. These are trees that were grown in the ground in a tree farm. Their roots are cut so that they can be transplanted into your landscape. They require more water than containerized plants because their root balls are bigger (often two to three feet in depth), and they have been through the trauma of having their roots cut. One easy way to do this is to have different sprinkler heads installed at the base of each tree. Adjustable flood bubblers are ideal. They flood the base of the tree, giving much more water to it than to the surrounding plants. The adjustable feature allows you to cut down on the water by tightening a screw, so the water is diminished as the tree becomes established.
Another great alternative for establishment watering is a soaker hose. The water comes slowly out of the sides of a soaker hose, seeping down to the roots of a plant. These low-volume hoses are ideal for establishment watering because the slow soaking gives the roots time to absorb the water. Quick, high-pressure water sometimes goes by a plant’s roots so fast that the roots do not have a chance to absorb the water. Soaker hoses can be placed either under or on top of the mulch.
Soaker hoses are ideal for establishing field-grown trees in the Palm Beach landscape. Wrap them around tops of the root balls (on top of the ground) in a circle at the bases of the trees. Palms normally lose their lower fronds during establishment, but I have seen them retain all their leaves with soaker hoses. These low-volume hoses are also ideal for beds of shrubs and groundcovers. They do not work well for grass.
Soaker hoses require much more time to apply one inch of water than conventional sprinklers. For trees, plan on using the soaker hoses for six months. Let them run all night for the first three weeks, turning them off in the daytime. Cut down to five nights a week during the fourth week, four times a week during the fifth through eighth week, and three times a week during the next two months. Cut down to twice a week for the next two months. Obviously, turn them off when it rains enough to give the root balls a good soaking.
For shrubs and groundcovers, plan on using the soaker hoses for a minimum of four hours at each application. Watch the plants carefully for signs of wilt, and then turn the hoses on again. The establishment period is about six months for shrubs and groundcovers, but they will not require anywhere near as much water as field-grown trees. The schedule for establishment watering of shrubs and groundcovers varies tremendously, based on temperature, wind, and sunlight. The following schedule is an estimate for either soaker hoses or traditional sprinklers:
First month – every day
Second month – every other day
Third month through sixth month – twice a week
Remember that the plants need twice as much water on 95 degree days than they do on 80 degree days. If plants are planted in July and there is no rain for a week, they may require twice as much water or twice a day for the first month. If they are planted in shade in December, they may only need one half the water stated above. This schedule assumes one inch of water per application. Purchase a rain gauge so you can measure your rainfall. If it rains one inch or more, do not water that day.
The number one reason for plant death in the landscape is lack of water during the establishment period. In most instances, the cause is not lack of turning on the water but a clogged sprinkler head. If a piece of sand gets into a head, it can clog it, and the water will not hit part of the area the head should cover. If you experience plant wilt on one plant but not on the same type of plant that is next to it, turn on your sprinklers and see if both are receiving equal water. Another way to test a system easily is to put out multiple coffee cans, run the system at night, and then see how much water collects in the cans.
After diligently watering during the establishment period, many find it hard to understand that, for shrubs, trees, and groundcovers, the need for water greatly diminishes after the first six months in the ground. Overwatering after establishment is a frequent cause of plant problems. After the roots of the plant have grown, the roots not only give the plant a place to store more water, they also grow deep into the ground to pick up water you do not see on the surface. The grass becomes the major water user.
The establishment period water is weaned off over a period of time in the Palm Beach landscape. This weaning encourages the roots of the plant to grow deeper to find water. If the roots are large and healthy, the leaves and flowers follow suit. Plants properly weaned off water are much more able to withstand drought conditions than plants that are habitually overwatered. Overwatered plants do not develop sufficient root systems that will allow them to go for a long time without more water.
I have seen many instances of daily watering of plants that have been in the ground for years in the Palm Beach landscape! Their roots have never grown down more than a few inches to reach for water. Overwatered plants are nutritionally deficient because water causes their nutrients to wash quickly through the soil. They are leggy and gangly because the overwatering causes extra fast growth. They are often full of pests because plants in a weakened state attract pests. Fungus is a frequent disease problem. Their life-spans are greatly diminished.
The plants I recommend are tolerant of differing water conditions in the Palm Beach landscape, which is very important. The cornerstone of the low water, low maintenance landscape is its ability to adapt to our environment. The Palm Beach climate is normally dry in winter and very wet in summer. If desert plants are planted when we have a drought, they may not be able to take the next tropical storm that drops twelve inches of water on the garden in a single day. But, even the most tolerant plants cannot handle daily water for years on end.
Using adaptable plants keeps both the design process and the sprinkler system easy because the plants can all be watered on the same schedule. The grass needs more water than any of the shrubs, so it makes sense to put it in a separate sprinkler zone, if possible, in your Palm Beach landscape.
Be sure to water at night or early in the morning. Watering at noon can use twice as much water than watering at four in the morning because of evaporation.
The amount of water your plants require varies, based on the type of plant and the type of soil. It is also greatly affected by the amount of sun, wind, and heat. Because of the differing environmental conditions, it is impossible to give weekly watering requirements for all plants in the Palm Beach landscape. In my books, I have put down estimates for each plant. Use these estimates as just that – estimates. Watch your plants and see how much water they need in your landscape. After six months in the ground, few plants in this book need water more than once or twice a week, unless they are in fine sand, high wind, and bright sun all at the same time! Signs of water stress include wilting or having the bottom leaves of a plant yellow and fall off. We often get more than one inch of water a week, so use nature for plant water when it’s available, and use sprinklers only when it is very dry.
Keep your sprinklers well maintained. They require checking at least monthly. Turn the system on and run it through all its zones. If a head is broken, a geyser can result, which is a huge water waster.
Grass is the biggest water user in the Palm Beach landscape. If possible, keep it on separate sprinkler zones from your shrubs, trees, and groundcovers. Then, you can water it more than the rest. Most people who have this system find they seldom water their shrub and tree areas.
Given our situation of more frequent water restrictions, it makes sense to condition your grass for drought. Grass that is not conditioned will not withstand a drought very well. The same principles that apply to shrub watering apply to grass: water deeper and less often to produce a healthy root system. Frequent, light waterings are the worst thing you can do to your grass.
Do not water your Palm Beach lawn until you see it needs water. Signs that a lawn needs water include: footprints remain long after being made, leaf blades have folded in half lengthwise, and bluish-grey spots appear in the lawn. Apply 3/4 inch of water. Do not water again until you see the same signs. Expect it to take up to six weeks to condition your grass to go for more than a few days without showing signs that it needs water. In time, it will go for longer periods because it is growing a larger root system. You will receive the added benefit of a better looking, thicker, greener lawn through this process.
Mowing grass higher not only toughens it against drought but also increases its general health. Use the highest setting for your mower blade. Keeping mower blades sharp also increases the drought tolerance. And, do not cut too much at once; remove no more than one third of the height with each cut.
This article is taken from:
“Easy Gardens for South Florida” by Pamela Crawford. © 2001 Color Garden Inc.
All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, on the internet, recording or any other information storage and retrieval system, without prior permission in writing from the publisher.