Topping my to-do list every day these mid-summer months: Water outdoor plants! (In fact, I’ll likely water a second time, this super-sunny July day.) Here are a few dos and don’ts to help you tackle the task in a way that your flowers, vegetables, bushes, and trees will appreciate!
DO
• Water in the morning. An early-morning watering, when the ground and air temperatures are still cool, will ensure that your plants’ roots get the maximum amount of water in prep for the coming sunshine. If you wait until later in the day, more of the water will evaporate before it gets to the roots. Also, if you get water on the leaves in the morning, it should evaporate without any damage like it might cause in the heat of the day or in the evening (see below).

• Water slowly and thoroughly. Slowly so that the water doesn’t run off and thoroughly because it’s better to give plants a big, deep drink than to water them shallowly, even if the lighter waterings are more often. If you don’t water deeply enough, only the upper soil becomes wet, and your plants won’t be encouraged to grow deep roots. Take your time. I like to water my roses slowly, from one end to the other, and then back again, with a second drink that can really soak in.
• Let the soil dry a bit between waterings. Overwatering (in this case too often) will cause roots to drown and plants to die. It’s the number-one mistake of avid beginning gardeners and houseplant owners. That said, try not to wait until the plants are droopy or bone dry, or you’ll stress them. There are moisture gauges for measuring such things, but I like to use my finger. Just put your finger straight down into the soil. If it’s dry an inch down (as far as the first knuckle past your fingernail), then it’s time to water. (Fun aside: This knuckle is called the distal inter-phalangeal joint, or DIP for short. Appropriate, right?) Plants have different moisture preferences, but I find this “DIP” test works for almost all plants.
• Water at the base of the plant. Watering at ground level will direct the water to the roots; if you water overhead the plants actually form a bit of an umbrella, keeping some of the water from reaching the soil. (More about why overhead watering is a don’t, below.) A watering wand is handy for this job.
• Water all around the plant. Most plants have a spot where they’re easiest to water (there’s an opening for the hose or can spigot, or you can reach it easily without getting wet yourself, for example). But watering completely around the plant rather than in one spot will encourage the plant to grow roots evenly. This means it will be more solidly in the ground, and the plant will grow more evenly above ground, too.
• Water plants in pots more often than those in the ground. They’ll dry out more often, especially on hot summer days. (And, of course, outdoor pots dry out much more quickly than indoor pots.) This is especially true if they’re in terra cotta pots, which I love. I water most potted outdoor plants in the early morning and again in the afternoon on really hot days. Also note that potted plants vary in their need for watering attention. Succulents can bask in the heat longer than impatiens, for example.

• Keep up the good work. Continue to water newly planted bushes and trees clear through their first growing season. They don’t need as much watering as they did their first month (when they need watering a few times a week), but they still need, say, a weekly watering if Mother Nature doesn’t step in. Even bushes and trees that have been around for years will need watering if there’s a dry spell.
• Soak your potted plant if the soil is bone dry. If your potting soil seems to be shedding water (it happens, especially if it’s been allowed to dry out completely), immerse the entire pot in a bucket of lukewarm water for about half an hour. (Place it so the water comes up over the lip of the pot.) Remove the pot and place it in the shade until the plant is revived.
• Mulch plants to retain moisture. Mulch helps cool the soil, slow evaporation, and control weeds. Besides, it looks tidy. Also, when you water a mulched area, it doesn’t make the muddy mess that a non-mulched area sometimes does. Make sure when you water that you give enough to seep past the mulch to the plant roots. (Mulching potted plants provides them with these same advantages.)
• Check with local ordinances about watering. Some communities have ordinances and/or guidelines for watering that you should follow.
DON’T
• Water in the heat of the day. During the hottest part of the day, much of the water will evaporate before it’s drunk by the plant roots. Also, water that beads on the plant leaves can cause them to burn when it’s sunny because the water droplets magnify the sun. (If a plant is really thirsty, though, I wouldn’t make it wait for a drink. I’d just be careful to direct the water to the soil, keeping it off the leaves.)
• Water in the evening. Some experts suggest watering plants in the evening, when the soil and air are cooled a bit. And it’s true that watering in the evening prevents the water from evaporating quickly. But watering in the later hours can encourage insects and fungal disease, too. I try to water in the morning, but if I have to water at night (again, I won’t make a thirsty plant wait), I’m very careful not to get the leaves wet. (I’m especially careful with my roses, which are prone to fungus.)

• Use a sprinkler. Oh, if you’re running a sprinkler anyway to water a newly seeded lawn, then you may as well have it water your flowers. But in general, a sprinkler wastes a lot of water (in the air), especially on hot and windy days. Not much of the water makes it to the plant’s roots! And sprinklers can lead to leaf burn if it’s sunny. A soaker hose, on the other hand, will direct the water right to the roots. If you have a vegetable garden, you might consider investing in soaker hoses. BTW, I saw these directions for making a soaker hose out of a garden hose, which I think looks so smart!
• Blast your plants. Again, a watering wand that delivers a gentle spray is perfect. So is a watering can. A normal spray nozzle is apt to damage delicate leaves and flowers.
• Use softened water. Softened water (if you were to fill your watering can from indoors, for example) contains water that’s not good for your (indoor or outdoor) plants.
I’m off to give those terra cotta pots a second drink, though I bet the roses and bushes are still fine.
How are your outdoor plants doing these hot summer days?
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