What Your Japanese Maple Needs in July for Blazing Color That Lasts All Season – 5 Easy Tasks to Do Now

When I ask friends which landscape tree they love most, Japanese maples (Acer palmatum) get the nod more often than any other species. These beloved trees offer a staggering range of leaf color, and are also small enough to find a suitable place in almost every garden. This lovely small maple is also suitable for growing in containers on the patio.

Japanese maple care is not complicated but it’s important to offer them some help during the hottest months of the year, including July. This month is the very heart of summer. So you’ll want to protect your Japanese maple trees now to help them thrive the rest of the year as well.

Here are 5 important steps to take to safeguard your Japanese maple trees in July.

1. Don’t Let Trees Dry Out

Dieback and Japanese maple leaves turning brown in summer is usually caused by a lack of moisture. In July, you need to keep on top of the moisture situation. If you see your tree’s leaves looking dry or scorched, you’re not doing enough. This is particularly true during the tree’s first year after planting. Be particularly careful if you are growing a Japanese maple in a container.

Keeping the soil well-watered under Japanese maples is the number one task for gardeners. How often should you water Japanese maple trees? The frequency depends a lot on climate and where the tree is sited.

During hot weather, you may need to water container-trees every single day. The soil of a potted Japanese maple should never be permitted to dry out. Count on watering a tree planted in the soil two times a week if it gets direct sun, once a week for a tree sited in the shade. A moisture meter, like this one from Amazon, is a useful gadget and will make sure you are acting on correct information.

2. Follow Good Watering Practices

While watering is crucial for Japanese maples in July, it is also very important to follow the best watering etiquette. Make these “rules” your habit:

• Every time you water your trees, give them a deep watering to make sure that the entire root system is hydrated. This means more than a quick splash. For trees in the soil, let the hose run and water around the drip line for several minutes. For container trees, be sure to water until the excess flows out the drainage holes.
• Although rainfall can provide a good source of water for an established Japanese maple, toss in a deep watering every few weeks to top off the irrigation.
• Well-draining soil is important since these trees will not tolerate consistently wet soil that comes from overwatering.
• Water early in the morning. Later in the day, it will be hotter and the water you provide your Japanese maple will evaporate. While some gardeners prefer to water in the cool of the evenings, moisture that remains on the trees at night can result in fungal diseases.
• Don’t use overhead sprinklers that wet the maple leaves, since this can cause leaf scorch during the heat of the day. Invest in a good soaker hose, like this one from Amazon, to deliver water to the tree’s root zone.

3. Provide Heat & Wind Protection

We think of July as hot and still, but in some regions, hot winds are a feature of summer. The combination of hot, drying winds and blazing sunshine will take a toll on your trees. You can avoid this issue by planting your Japanese maple in a site where it is protected from harsh winds and also shaded from hot sun. If it’s already established in an exposed location, you’ll need to step in.

Windy conditions in summer will both stress your Japanese maples and likely limit the leaf color. Mulch can provide wind protection as well as keep roots cool. If you already mulched around the tree in spring, it may be time to add some more.

Organic mulch is best for Japanese maples, since it will disintegrate into and improve the soil over time. You’ll want to weed the area under the tree up to the drip line before you add mulch. Then water deeply and well since the mulch will seal that moisture into the ground. Finally, add a 2-3 inch (5-7.6 cm) layer of mulch over the area beneath the canopy, extending it to the drip line.

The mulch should be far enough away from the trunk that there is no chance of it touching. Consider using a pine-based mulch, like this one from Amazon, for this acid-loving tree.

4. Prune Now, If Necessary

Japanese maples don’t need much pruning. They naturally have an elegant shape. But July is the perfect time to lightly prune Japanese maples to keep trees healthy and looking good.

Use sharp, sterilized pruners, like these expert-approved Felco pruning shears, and snip out badly-placed or crossing shoots. If you want to reduce the size of your tree, trim long branches back to a well-placed side branch. Make clean cuts just on top of the branch collar.

If your maple’s canopy is dense, consider thinning it out a bit to allow light and air to penetrate. Focus on inward-growing branches and be sure to maintain the tree's natural shape. Postpone major pruning tasks for late winter or early spring when the tree is dormant.

5. Watch for Pests & Diseases

It’s a sad fact of summer: pests and diseases show up to party hearty. Japanese maples are not immune to this, so inspect them regularly for aphids, spider mites, scale, and fungal infections. These trees are tough and can shrug off a lot of problems, but when they are attacked by insects or diseases in July while they are fighting heat stress, they can be seriously impacted.

If you spot an issue, act promptly. Treat fungal diseases with fungicides, like this spray from Amazon, and bugs with the appropriate organic insecticides. Neem oil, which you can also find on Amazon, mixed with water and dish soap works for many insects.