How to Keep Your Trees and Shrubs Healthy

By Melinda Myers - horticulturist and gardening expert
August 15, 2026

Proper watering, mulching, pruning with a purpose, and fertilizing when needed are key to keeping your trees and shrubs healthy and beautiful for years to come. If your plants are struggling, evaluate your maintenance practices and make needed changes to improve their health. With the four keys to proper care, you can grow healthy and beautiful trees and shrubs.

Proper Watering Trees and Shrubs

Let the weather, soil type, and the plant you’re growing determine your watering schedule. High temperatures and fast-draining soils dry out quickly, and the plants will need more frequent watering. Cooler temperatures and slow or poorly drained soils stay moist longer. Established trees with larger root systems and drought-tolerant trees need less frequent watering than moisture lovers and new plantings.

Water new tree and shrub plantings thoroughly and often enough to keep the root ball and soil beyond slightly moist, not soggy wet. Check newly planted trees growing in well-drained soils at least twice a week and those in heavy clay soils at least once a week. Potted trees and shrubs are usually grown in soilless potting mix. This often dries out more quickly than the surrounding soil. You may need to water the root ball more often than the surrounding soil to compensate. Continue monitoring soil moisture closely for the first two years after planting. It takes trees and shrubs this long to establish.

Don’t overlook established trees that still need to be watered during dry periods. Check the soil moisture and water established trees thoroughly when the top 4 to 6” of soil are dry. Dig down 4 to 6” to feel the soil. If it is crumbly and dry, it is time to water. Or use a screwdriver to monitor soil moisture. Stick the blade into the top 6” of soil in several locations under the tree canopy. If it is difficult to push through the soil, it is time to water.

Always water thoroughly, moistening the top 12 inches of soil under the tree canopy, starting at two feet from the trunk of trees. You’ll need to apply 10 gallons of water for each diameter inch of the tree measured at 4.5’ high. Do the same for evergreen trees, extending the area by 3 to 5’. Thoroughly water the soil under and several feet beyond that covered by the shrubs.

Continue monitoring soil moisture in the fall and water thoroughly as needed when temperatures are 40°F or above. This is especially important for evergreen trees and shrubs that continue to lose moisture through their needles and leaves throughout the winter.

Here are a few ways to make the job easier for you, because if it is easy, you are more likely to do it.

Use a soaker hose to place water directly on the soil and above the root zone of the tree or shrub where it is needed. Set the soaker hose in wide circles under the tree, starting several feet away from the trunk, with the loops several feet apart. You’ll spend less time dragging hoses and sprinklers and waste less water.
Or convert discarded food-grade 5-gallon buckets into slow-release watering devices. Drill holes in the bottom of the buckets. Place several buckets beneath the tree canopy. Fill the buckets with water and let gravity do the work.

Proper Mulching for Trees and Shrubs

Mulch the soil surface around trees and shrubs to conserve moisture, reduce competition from grass, suppress weeds, and prevent weed whips and mowers from damaging the plants. This means less work for you and a better growing environment for the plants

Create as large a mulch area under your trees and surrounding your shrubs as you can tolerate. Spread a 2 to 3-inch layer of shredded bark or wood chips over the soil surface. Pull the mulch away from the trunk and off the shrub stems. Piling mulch against the plants can lead to rot and other problems.

If large beds of mulch around your trees don’t fit your landscape design, create a beautiful garden instead. Dress up the space with groundcovers, perennials, and shrubs that add texture and seasonal color. Be careful when planting under mature trees. Do not cover the roots with soil, as this can result in decline and even death of your tree in the coming years. Avoid deep tilling, which can damage surface roots and fine feeder roots that absorb water and nutrients. Instead, dig relatively small holes between large roots to accommodate the plant, mulch, and spot water new plantings. It may take a bit longer for them to fill in, but your tree will be healthier and longer lived.

How to Prune Trees and Shrubs

Wait a year to do major pruning on newly planted trees and shrubs. The more above-ground leafy growth, the more energy the plant can produce to help develop a robust root system. Just remove broken and damaged branches at planting.

Once established, prune young trees and shrubs to create a strong structure. Starting the process early results in a sturdier plant with smaller pruning cuts. Properly trained plants are more resistant to storm damage than those that have been neglected for years. Continue to remove broken, crossing, inward-facing, and rubbing branches on both trees and shrubs.

Use bypass pruners or loppers with two sharp blades to make clean cuts on smaller branches that will close more quickly.
Break out the pruning saw for larger stems and branches.
Make cuts above an outward-facing healthy bud or branch or flush with the branch bark collar, the swollen area where the branch adjoins the tree trunk.
Consider hiring a certified arborist with the training, experience, and equipment to prune your trees.

pruning a dead tree branch

Avoid excessive pruning that can stimulate unwanted growth that will need to be managed in the future. When major pruning is needed, spread it over several years for better results.

Maximize flowering on ornamental shrubs by pruning spring-flowering shrubs right after flowers fade. These produce their flower buds the summer before the spring floral display. You can prune summer-flowering shrubs anytime during the dormant season since they flower on the current season’s growth.

Skip pruning plants and wound dressings that don’t prevent decay and may hinder the tree or shrub’s ability to close the wound and defend itself against insect pests and disease. A well-made and properly placed pruning cut is the best way to help your plants. 3 Biggest Pruning Mistakes

Fertilizing Trees and Shrubs

Fertilize only as needed. Trees and shrubs get most of their nutrients from fertilizer applied to surrounding lawns and gardens. But there are times we may want to lend a helping hand. The best time to fertilize is early spring, before growth begins, or fall, once plants are dormant. Avoid late summer fertilization that can promote late-season growth subject to winter injury.

Use low-nitrogen slow-release Milorganite fertilizer to promote balanced above- and below-ground growth for trees and shrubs in need of a nutrient boost. The 85% organic matter in Milorganite also helps improve the soil.

Fertilize with Milorganite to help promote flowering on established plants that fail to bloom. Research found that when microorganisms release nutrients from Milorganite pellets, it also releases some of the phosphorus and potassium bound to the soil. Phosphorus promotes root growth, flowering, and fruiting, while potassium increases disease resistance and hardiness.

Follow the recommended rates on the Milorganite bag or use the chart below. Just spread the Milorganite over the mulch area and lightly rake it in. Let nature move it down through the soil and to the plant roots.

Milorganite Fertilizer | Tree Application Rates
Planting Type	Application Rate	Suggested Application
Established Tree	5 lbs per inch of trunk diameter	Pour into holes (1” wide x 12” deep) spaced 2 feet apart along drip line. The second best option is to broadcast Milorganite in a circular band around the drip line of the tree.
Transplanted Tree	½ lb per foot of tree height	Mix with soil at the bottom of the planting hole prior to inserting the transplanted tree. 3 months later, hand spread an equal amount of Milorganite slightly past the drip line.

Milorganite Fertilizer | Shrub Fertilizer Application Rates
Planting Type	Application Rate	Suggested Application
Established shrub beds	5 lbs per 100 sq ft	Scatter uniformly over the soil surface and work in with a hoe or rake. For individual shrubs, apply 1 lb of Milorganite per shrub in the root area.
Transplanting shrubs	½ lb per feet of shrub height	Loosely mix with soil at the bottom of the hole prior to inserting shrub. 3 months later, hand spread 2 lbs of Milorganite under the plant and lightly rake into the soil.

You’ll need a different approach for trees growing in the lawn. Apply small amounts of the recommended amount of fertilizer throughout the area under and six feet beyond the branch spread. Start two feet away from the trunk and every two feet along concentric circles around the tree. Use a dandelion digger or similar tool to apply the fertilizer 6 to 12 inches below the grass roots for the tree to absorb.

Signs Your Trees and Shrubs are Unhealthy

If your trees or shrubs have stunted growth, smaller than normal leaves, few or no flowers, and branch dieback, they need your help. Review your current maintenance practices. Make sure the plants are receiving sufficient water and mulch as needed. Take a look at this list of Don’ts and Do’s to see what, if any, adjustments or fine-tuning you need to make in the way you plant and maintain your trees and shrubs. It may just be a small change that can greatly improve your results.

If you suspect an insect pest or disease, consult your local extension service for help diagnosing and tips for treating the problem. Don’t fertilize during drought or when plants are stressed. This promotes more leaf growth while the plant is trying to recover. Manage the cause of the stress before adding fertilizer.

Seasonal Care for Trees & Shrubs

Here’s a brief overview to help keep your trees and shrubs healthy

Spring

Check plants for any damage from winter storms and animals. Correct or contact a professional to manage the damage.
Prune summer-blooming shrubs and trees if needed before growth begins.
Wait to prune spring-flowering shrubs until right after the flowers fade for maximum bloom.
Replenish mulch as needed to maintain a 2 to 3” layer. Pull the mulch away from the trunk of the trees and stems of shrubs.
Fertilize if needed.
Water new plantings regularly and established plants during dry weather.

Summer

Continue watering new plantings thoroughly as needed.
Water established trees and shrubs thoroughly during dry periods.
Avoid damaging tree trunks and shrubs with mowers and weed whips. Create larger mulch or garden beds around the plants to eliminate the need to hand trim while improving the growing conditions for your plants.
Monitor the trees for insect pests, diseases and animal damage. Identifying problems early makes it easier to successfully manage them.

Fall

Continue to water as needed when temperatures are above 40°F.
Water all plants, especially evergreens, thoroughly before the ground freezes.
Replenish mulch as needed to maintain a 2 to 3” layer. Pull the mulch away from the trunk of the trees and stems of shrubs.
Fertilize if needed and not done in the spring.
Protect trees and shrubs susceptible to animal browsing with fencing or repellents. You’ll have greater success keeping them away than breaking the habit once they find your plants.

Winter

Look for opportunities to add trees and shrubs that provide winter interest to your landscape with berries, form, and interesting bark. Add these to your plans for the coming season.
Do dormant season pruning as needed. It is easier to see the structure and more easily identify where to make the cuts on a leafless plant.
Avoid deicing salts that can damage plants. Instead, shovel the snow off walks and drives first, then use a plant-friendly deicing salt only if needed.

Make proper tree and shrub care part of your year-round maintenance. Investing time in these plants results in years of beauty, environmental benefits, and enjoyment.