Summer Tree & Lawn Care in the Northeast: A Guide to Helping Your Landscape Thrive in the Heat Seasonal Care A practical look at summer maintenance for your property. We'll cover when to prune, how to water effectively, and ways to manage insects so you can enjoy your yard this season. Designed for homeowners in the Northeast, Mid-Atlantic, and other temperate regions with cool-season lawns. How to Help Your Landscape Handle Summer Stress Summer is when your landscape is at its most active and most vulnerable. Your trees and lawn are in their peak growing phase, but this is also the season when your property faces the most stress. The combination of heat, rainfall, and a surge in insect and disease activity creates significant challenges for your landscape. But there’s good news, too. Much of the summer damage is avoidable, and a little attention now can save you from dealing with sick or declining plants and costly replacements later. Early Signs of Heat Stress and Drought to Watch For By the time leaves turn brown and drop, it's often too late to reverse the damage. Heat stress shows up in subtler ways before you reach that point. Wilting leaves in the afternoon that perk up by morning are a classic sign. You might also notice leaves curling inward, or a touch of early fall color appearing on a tree in July or August. These earlier signs are your window to act. If you catch them, monitor soil moisture and adjust your watering practices before the stress progresses further. One of the simplest ways to check for heat stress is to dig a few inches into the soil (or deeper around trees) to evaluate moisture levels. If it's dry and crumbly, your plants need water. It is worth checking even after a brief rain shower, which often only wets the surface and evaporates before the water can penetrate to the roots and do any real good. Keeping the soil properly moist is especially critical for newly planted trees that haven't yet developed deep roots. How to Water Trees and Plants the Right Way in Summer It might seem right to give your plants light sprinklings often throughout the summer. But for established plants, frequent, shallow watering does more harm than good, mostly by making them reliant on you and more vulnerable to heat. Instead of frequent, light watering, it’s usually best to water deeply and less often. The goal is to drive moisture deep into the ground, which trains roots to follow it down. A general rule of thumb is to provide about one inch of water per week through rainfall or supplemental irrigation. This varies based on climate, soil type, and tree age, but in most areas, during a heat wave, you'll need to supplement with extra watering. Early morning is the best time to water. You lose less to evaporation than in the midday sun, and the foliage has time to dry off before nightfall, which cuts down on fungal diseases. Common Summer Insects That Can Damage Your Landscape Insect populations explode in summer. Beetles skeletonize leaves, bagworms feed on evergreens, and spider mites damage foliage by feeding on plant tissues. The list is extensive, so it’s important to stay on top of insect activity on your property. If you work with an experienced ISA Certified Arborist®, they’ll walk your property and inspect the leaves for signs of insects. Many symptoms, such as trees with holes, plants with discolored leaves, or sap oozing from bark, require further investigation. Catching an insect problem early in the summer may be early enough to address it. If you discover severe damage or infestations as the heat rises later in summer and fall, the damage may be done, leaving your plants more vulnerable heading into winter. Insects and ticks affect human health, too. Ticks and mosquitoes are at their peak from late spring through August. Targeted treatments around landscape edges and areas where ticks and mosquitoes are most active can help make outdoor spaces more enjoyable throughout the summer. Read more about the tick lifecycle here. When Summer Pruning Helps and When to Avoid It For many tree and shrub species, it’s usually smart to wait to prune until the dormant season, but that doesn't mean that come summer, you can put your pruners away completely. Summer is a good time to remove dead, damaged, or diseased branches. If you see a dead, damaged, or diseased branch, ask your arborist to cut it out. Dead wood is an open invitation for insects and decay, and removing it is almost always the best choice to protect the health of the rest of your tree. On most trees and shrubs, you can also do light shaping in early summer. But once the real heat sets in, it's best to avoid any larger cuts as heavy pruning creates wounds the tree must heal while it's already stressed by heat and other summer stressors, leaving it vulnerable. Summer Lawn Care Tips Your approach to the lawn in summer depends on your grass type and climate. Your arborist can help determine the right course of action, but the end goal is to reduce stress on your lawn so it can perform at its best during the warmer summer months. If you have cool-season grass (like fescue or bluegrass), it’s going to grow more slowly in the summer. It may temporarily go dormant and turn brown during periods of prolonged heat and drought. This is normal and doesn’t require a heavy dose of fertilizer to green it up, which can stress it more. One of the tips we provide most often is to raise your mower deck. Keeping the grass at 3.5 to 4 inches tall shades the soil, holds moisture, and protects the plant's crown. Warm-season grasses (like Bermuda or Zoysia) love summer weather. They can handle a feeding in midsummer if needed, and you can mow them lower, but we suggest sticking to the recommended height for your grass type. The best rule of thumb is to never cut off more than one-third of the grass blade at a time. Mowing too low (also known as ‘scalping’) can enable weeds to outgrow the grass. We always recommend leaving blooming plants like azaleas and rhododendrons untouched throughout the summer. By this time, they’ve already formed their buds, so pruning them during that window can significantly reduce the following year’s blooms. How to Control Weeds During the Summer Summer brings weeds, but you’re not helpless against them. The key is to spot-treat weeds as soon as you see them. For garden beds, a fresh layer of mulch about 2 to 3 inches deep is a best practice to help prevent weed growth over the summer. Mulch smothers weeds, keeps in moisture, and when it’s done right, it can be a big help. Be sure not to mulch too close to tree trunks when adding it near trees. Mulch shouldn’t pile up against the trunk, making a “volcano”, because it can suffocate the root system and lead to larger root issues. How to Prevent and Manage Summer Plant Diseases Powdery mildew, leaf spot, and root rot all thrive in hot, humid summer weather. If you have dense plantings that stay wet for a long time after a rain, you need to create good airflow to help prevent the spread of disease. You can do this by removing interior branches to thin out plants and trees, which helps dry areas where mildew or other conditions like to grow. If you have already detected a disease on one of your plants, we often recommend treating it as soon as possible, but it’s best to consult with your arborist before applying any at-home treatments to ensure you are treating the right disease in the best way. Often, waiting to treat can allow diseases to spread and may make them more difficult to manage. Targeted Summer Treatments for Common Landscape Insects If you’re dealing with insects, summer is the time to address a few specific issues: Bagworms: Treatment is only effective in late June or early July while the larvae are small and feeding. Once bagworms seal their bags, it may be too late, so contact your arborist early to keep these insects under control. Spider Mites: These mites explode in hot, dry weather. Keep an eye out for leaves with bunches of tiny holes, and treat quickly if you find them. Grubs: Preventive treatments for Japanese beetles and other grubs are typically applied in mid-to-late summer. Borers: If you have a valuable tree (like a birch or an ash) and suspect borer activity, call an arborist soon. These insects can cause significant damage before symptoms become obvious. Protect Your Landscape by Staying Ahead of Summer Problems Summer throws a lot at your landscape, and factors such as heat, insects, dry spells, and sudden downpours can all take a toll. But the properties that look great in the fall and green up beautifully in the spring are most likely the ones that got consistent, thoughtful attention through the summer months. A little effort now keeps small problems from becoming big headaches later.Need help caring for your landscape this summer? Schedule a complimentary consultation with one of our experienced ISA Certified Arborists®. We'll evaluate your trees, shrubs, and lawn, identify signs of heat stress, insect activity, or disease, and recommend solutions tailored to your property's needs. Contact us today to schedule a consultation with an expert arborist.