How to water garden plants the right way: Philly heat wave #2

Many gardeners have just completed, or have almost completed, their spring planting. If you’ve planted a vegetable garden, planters with annuals, new shrubs, or you’ve divided, transplanted, and planted perennials; get ready to begin watering the garden, correctly, for the next week or so. The temperature is rising this week in the Philadelphia region with a possible second heat wave on the horizon. Philadelphia’s Accuweather predicts temperatures to reach 98 degrees by Thursday.

Watering the garden incorrectly can be just as damaging as not watering at all. Most avid gardeners cringe when they see someone watering their plants while standing back and spraying the leaves and the bed with the hose, or if someone is watering the bed in the hot, mid-afternoon, summer sun, or late evening. These are three common mistakes, other than not watering or watering too much.

Here’s how to think about watering a plant; imagine standing in front of the sink and filling up an empty one gallon milk jug with water. How long does it take before the gallon size jug is filled? It takes about one minute. That’s how long it would take for a plant in a gallon size container, or a plant already planted in the ground with the same depth and width, to get water from bottom to top. If you go over to your garden, after you’ve sprayed it with the hose, and dig down 2-3 inches, you’re more than likely to find dry soil. This can cause the roots to become shallow because they will search for the water in the top layer. Then, of course, the roots near the surface dry out faster, which can equal death in one hot afternoon. Soak it!

Basic Watering Rules: For both Garden Planters and Plants in the Ground

Water in the early morning, if possible, because watering plants in the evening can invite plant mold and mildew; especially on perennials like monarda or mums. Plants that are susceptible to flower blight or leaf spot must be watered earlier than later, so the sun has a chance to dry the leaves, which prevents disease.
Don’t water the foliage of any plant in the hot afternoon sun because it will burn the leaves.
Water plants long enough to reach the entire depth and width of the plant, as described in the second paragraph. Too much shallow watering will lead to shallow roots; and shallow roots lead to the plant drying out much sooner in hot or drought conditions.
The water speed at which the gardener waters the plant can result in run off instead of penetration; so don’t water using a hose on a full force setting. Forceful settings can also flood pots, disturb seeds and roots, and destroy seedlings...duh...right?
If your plants are watered correctly and thoroughly in the morning, and they wilt in the hot afternoon sun, especially seedlings, just leave them alone; they'll recover during the evening.
If you've forgot to water, and your plants are wilting, water the base of the plant or in the pot, not on the leaves no matter what time of day it is.

Watering Garden Planters: Hanging Baskets, Urns, Pots, and Window Boxes

When watering planters, hanging baskets, pots and urns, remember to water in the center of the pot and not just on the sides.
Water the containers until the water flows from the drainage holes at the bottom of the pot. Too much shallow watering will lead to shallow roots; and shallow roots lead to the plant drying out much sooner in hot or drought conditions.
Once the water escapes from the planter, continue to water for at least another minute or two so that the pot will be drench completely, which includes the outer circumference were roots also travel. Many times a quick hit of the hose doesn’t saturate the sides all the way to the bottom.
Any potted plant that is located in full sun and uses a lot of water such as a fuchsia, as well as, any root bound plants may have to be watered twice a day.

Watering Plants in the Ground

Water plants long enough to reach the entire depth and width of the plant, as described in the second paragraph. Too much shallow watering will lead to shallow roots; and shallow roots lead to the plant drying out much sooner in hot or drought conditions.
Always water plants, shrubs and trees at the drip line.
Foundation plantings along a stone or brick wall of the house must be watered, especially in full sun, because the sun reflects off the stone and also holds in heat. You can use a soaker hose or sprinkler if the area is large. If any of the foundation plants are located under a gutter, awning, or the part of the roof that hangs over the house, then gardeners must keep an eye on them because only sprays of rain will reach the plant. If possible, avoid planting directly against the house for these reasons.
When planting on hills, banks, and berms that the water will run off before it sinks down into the plant. Water plants on slopes by applying water for a few seconds, then remove the hose until that water sinks in, then re-apply water, then remove, and then continue on and off until you feel the water has reached the roots. Many shrubs and trees die on slopes because the water immediately runs off and never gets to the roots.
Never let newly planted trees or shrubs dry out. Trees and shrubs can be very unforgiving if left to dry out, and will not rejuvenate when finally watered; whereas most perennials and annuals that dry out will bounce back if watered within a day or so. Once established in a month or so; shrubs and trees should be fine unless a drought occurs.

Watering the Lawn

If you’ve planted a new lawn, patched the old lawn with new seed; or if your grass is turning brown, or you hear your grass crunching when you walk on it, like when you're eating Captain Crunch, you might consider watering it. No cutting the lawn until we get some rain. Call the lawn service off this week.

Nowadays, there are self-watering gadgets for watering houseplants, sprinkling systems for gardens and landscapes, and irrigations systems for farms; all of which make watering a no-brainer and can be performed without the human touch. But for the die-hard gardener and nature enthusiast, watering is part of the fun.

Don’t spoil the plants with water; too much can increase the garden’s need for water. It can also kills the plants from lack of oxygen to the roots which causes root rot. Drowning the roots is a common reason why many plants die. The other obvious reason plants die is because the plants aren’t being watered enough. If you have problems with time and watering, try drought-resistant plants that take less water and avoid planters because they require almost daily watering.

There’s not much a gardener needs to water in the established garden and landscape. Watering should only be done for reasons such as drought, which usually occurs in the summertime; after newly planted bulbs, lawns, shrubs, trees, and perennials are installed, which could take a few weeks until they are established; after dividing and transplanting; and immediately after applying fertilizing to any plant, which includes the lawn. Of course, in spring, seeds, seedlings and vegetables should be watered until established.

If you have newly planted plants or pots, consider watering every other morning for the next week, unless there are water restrictions. As far as your existing shrubs and plants that are established; it hasn’t rained in about a week, and if there is no rain in the forecast within the next week, you may want to give them a shot of water. Gardeners must remember that conserving water for the planet is critical. Although watering can be fun and therapeutic; if there’s no need to water, don’t.

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