Discover Ohio’s Planting Zones – Plus 6 Keys to Keeping Flowers, Shrubs, and Trees Alive

Growing hearty produce, flowers, and plants succeed where the United States Department of Agriculture (USDA) says to do it. The USDA Plant Hardiness Zone exists to pinpoint the best place to plant and produce plentiful seeds based on average regional temperatures and frost dates.

The Old Farmer’s Almanac defines a hardy zone as a small area in a microclimate environment where temperatures differ from adjacent regions, sometimes hotter and colder. Hardy zones are near water, steep elevation changes, and urbanized areas. The USDA Plant Hardiness Zone Map has 13 distinct 10°F zones separated into 5°F subzones.

Each state map determines said zones by the region’s average winter temperatures. The Buckeye State boasts two main USDA hardiness zones, including Zones 5a, 5b, 6a, and 6b, with varying freezing temperatures. While Ohio classifies mostly as part of Zone 6, the section of Zone 5 also produces several types of trees, shrubs, and flowers, requiring key factors to flourish.

Timing, temperature, soil, hydration, pruning, and disease management sustain Ohio’s horticulture. The six key factors combined help all plant hardiness Zone 5 and Zone 6 foliage grow strong. Take, for example, hydration and pruning. Adequately watering foliage from either zone is critical in developing roots, as pruning flowers, shrubs, and trees helps them grow more robust. As it sounds, disease management helps fight against pests, fungi, and bacteria. Whether it is cold, hardy shrubs from Zone 5 or blooming flowers from Zone 6, Ohio is a great state to grow a garden of goods.

Along with six key factors, let’s get right to the suitable zones and how to develop flowers, trees, and shrubs.

USDA Zone 5

These plant hardiness zones are dominant in the northeastern and northwestern parts of the state and in the center of Ohio. Some of the best Buckeye vegetables in the state boast being from Zone 5, not to mention flowers, trees, and shrubs. 

Best Zone 5 Flowers

Zone 5 flowers are a long, bright, and beautiful addition to any garden. Some of the best flowers to grow in Zone 5 are delphinium, echinacea, lilies, salvia, hollyhock, coral bells, hyacinths, and aster. There are also up to seven types of perennials that grow best in Zone 5.

Timing

The short growing season in plant hardiness Zone 5 boasts a hearty fall harvest, as seen with the aster plant, bringing forth light purple flowers similar to daisies. Like other Zone 5 flowers, the hardy and thick-stemmed coral bell flower does well in the winter and mild summertime. May to October is the best time to plant Zone 5 flowers.

Temperature

Zone 5 varies between temperatures of -20°F to -10°F. Zone 5a has minimum average temperatures of -20°F to -15°F and Zone 5b is a minimum average temperature of -15°F to -10°F.

Hydration

Zone 5 flowers, especially perennials, prefer an average of one inch of water a week from April to September. It is essential during a drought to water Zone 5 flowers that cannot survive too much heat and not enough water. Testing soil moisture is simple. Just put your finger into the first inch of the soil to ensure it is not too wet or dry.

Soil

Plant hardiness Zone 5 roots withstand cold winter temperatures in soil, bringing these flowers back to life in the spring. Zone 5 flowers do well with mulch, which should never be too dry or wet. Soil temperatures moderate with mulch that keeps roots warm in winter and cool in summer.

Pruning

Pruning Zone 5 flowers and perennials only need to be cut at certain times annually. The spring and fall are best for trimming; however, the Old Farmer’s Almanac suggests perennial Zone 5 flowers can wait to be pruned after several hard frosts since roots revive and cause heartier growth.

Disease Management

Zone 5 flowering plants are less likely to die if planted with similar buds requiring the same soil moisture. Plant diseases are also prevented by not spacing flowers too close together, giving them a chance to breathe.

Best Zone 5 Shrubs

Some popular deciduous Zone 5 shrubs are abelia, bearberry, bush honeysuckle, and spirea. No matter what type of bush is in this zone, big and small shrubs can offer privacy. Some more ornamental than others, Zone 5 shrubs are a great addition to a garden.

Timing

Zone 5 shrubs love summer and grow strong in hot temperatures; however, the budding season is short. The timing of planting these shrubs is essential. The late spring to mid-fall is the best time to do so. 

Temperature

Shrubs can thrive in both 5a and 5b. They mustn’t be subject to temperatures below -20°F. A shrub gets damaged if it is too cold, so it is essential to cover shrubs if temperatures are near dangerous.

Hydration

Water perennial shrubs in Zone 5 weekly, giving them at least an inch in seven days. It is best to water only between April and September. Avoid soaking the shrubs every time you water them. Check the soil; if it is dry, then water shrubs twice a week to ensure roots stay healthy.

Soil

Yes, shrubs must not get too cold in the winter since that could damage them, but roots are different. Cold winter temperatures help roots become more robust, creating a brighter spring bloom. Soil for shrubs in this zone can be covered with mulch, which acts as a cooling agent in the summer for roots and a heating pad in the winter.

Pruning

Only prune shrubs in this zone during the spring and fall with one exception. If a shrub has damaged or dead leaves, it is important to clip or trim diseased leaves or branches. It is also just as important to not clip a shrub if it is too early to do so. Removing branches could result in the shrub not blooming at all.

Disease Management

There are many ways to manage disease for Zone 5 shrubs. It is also vital to ensure weeds are not present. Weeds can cause stress on shrubs, making them more vulnerable to infection. It may be time to replace the shrub if all else fails, including using specialized soil, sprays, and multiple trimming.

Best Zone 5 Trees

Some of the best trees to grow in Zone 5 are crabapple, Japanese tree lilac, red twig dogwood, weeping willow, native pawpaw, American sycamore, and river birch. Like shrubs, evergreen trees, including the Austrian pine, Fat Albert Colorado blue spruce, and emerald green arborvite, are also prominent in Zone 5.

Timing

Timing is everything regarding growing Zone 5 trees, with the first frost from October 13-21 and the last ice from April 7-30. Farmers suggest planting after the last frost since the soil should still be warm enough for seeds to sprout.

Temperature

Midwest tree development in plant hardiness Zone 5 also varies between temperatures of -20°F to -10°F. Native trees already developed in the microclimate do well here. Zone 5 trees thrive in the mild summers and colder winter zones.

Hydration

Watering tree soil is vital to keeping the tree healthy if there is a drought. Mature trees should get 10 gallons of water for every diameter inch of the tree. Like shrubs, new trees require more water for roots to grow deep. A suggested schedule is water daily for the first two weeks after planting, three to five days for three months, and weekly after three months.

Soil

Mulch is also suitable for Zone 5 tree soil, which needs different types of dirt for solid growth. Tree soil is either sandy, silty, loamy, or chalky. Clay and peat soil also do well with trees. Adding soil conditioner and composite is also suitable for Zone 5 tree growth along with the original noted types of tree soil.

Pruning

Like shrubs, trees get pruned for strength. Pruning trees is specific to age and season. Pruning cuts throughout the tree, either at the branch collar or axil, help it stay healthy. Crown thinning, which reduces the tree density, could require a saw or professional tree trimmers to tackle.

Disease Management

Like shrubs, tree pruning also prevents disease. However, tree disease management often includes spraying. A routine of fungicide spray throughout the tree, including the trunk, branches, and soil, can save a dying tree. Tree disease is often seen in bark changes and needles or leaves falling off prematurely.

USDA Zone 6

Zone 6 dominates most of the Buckeye State, with cold winters and warmer summers. It has a medium-length growing season and different microclimates across the state. Growing the best flowers, shrubs, and trees in Zone 6 also entails key factors from timing to disease management.

Best Zone 6 Flowers

The best Zone 6 flowers to grow are also some of the best Zone 5, including delphinium and aster. Some other strong flowers in the specifically temperate region are coneflowers, daisies, and daylilies, not to mention the five best annual flowers for Zone 6. 

Timing

The mid-length growing season makes planting and harvesting different from Zone 5. Planting Zone 6 flowers is best between the middle of March and mid-November, after the threat of any real frost.

Temperature

Unlike Zone 5, this zone’s temperature range is between -10°F and 0 degrees. Zone 6 includes subzones 6a and 6b. Zone 6a has an average minimum temperature of -5°F to -10°F, and Zone 6b experiences minimum temperatures of 0 to 5°F.

Hydration

Keeping the soil moist is critical to Zone 6 flower watering. Flower beds in this zone require at least one inch of water a week, with more needed for freshly planted seeds. Watering two to three times a week in the summer heat is ideal to keep flowers healthy.

Soil

Mulch is an excellent soil additive for Zone 6 flowers and soil conditioners or additives. As noted, soil temperatures are moderated with mulch to keep roots warm in winter and cool in summer, so layering this composite over soil helps sustain flower health.

Pruning

Cutting back flower beds ensures more flowers. The first part of pruning any flower is cutting off dead leaves or deadheads. Annuals and perennials, which are popular in Zone 6, can be pruned all year around. Late spring is the ideal time to prune most flowering plants; however, it is not good to prune too much in a growing season, no matter what flower type.

Disease Management

Pruning, watering, and spraying Zone 6 flowers are all ways to manage disease. A balanced fertilizer monthly can also keep disease away. Also, not spacing different flowers to close when planting helps.

Best Zone 6 Shrubs

Zones 5 and 6 share some of the best-growing shrubs, including dogwood and hydrangea. Dicentra, shadbush, and St. John’s wort are other colorful and bushy shrubs in this zone. Zone 6 shrubs can be more ornamental than hedges, which grow well in the region.

Timing

An extended growing season enables Zone 6 shrubs to plant in October, November, or December. Additionally, shrub roots best develop in not too hot or cold soil, and shrub roots store nutrients in the winter.

Temperature

Whether it is subzone 6a and 6b, shrubs here grow strong here between -5°F to 5°F. Warmer summers in this zone offer more sun and heat. Add that to the extended growing season in this zone, which makes for some bushy shrubs in Zone 6.

Hydration

Shrub hydration is the same in Zone 6 as in Zone 5, requiring a good soaking when first planted. Watering shrubs and flowers at night reduces evaporation from heat, giving the plant a better chance of soaking up some H20.

Soil

Shrubs in this region thrive in well-drained sandy and loamy soil. Clay soil tends to hold water and can clump, stunting shrub growth. Adding peat moss or composite also helps bush health if it is an evergreen shrub.

Pruning

Pruning a shrub is much like a tree. Do it when diseased stems and flowers are present. The Old Farmer’s Almanac suggests pruning spring-flowering shrubs directly after they flower and trimming down summer-flowering bushes in late winter or early springtime. Only prune Evergreen shrubs or hedges in the early springtime.

Disease Management

Planting disease-resistant shrubs offers less of a chance of decay. Pruning shrubs at the right time also helps them stay healthy. A well-balanced soil is also key, which entails not over-fertilizing or watering.

Best Zone 6 Trees

Zone 6 trees are similar to those of Zone 5, with the same types of evergreen trees and shade trees growing strongly here. The difference between the two zones is trees here will grow taller than in Zone 5 due to warmer temperatures in the summer. Some of the best Zone 6 trees are the American red maple, autumn blaze red maple, quaking aspen, saucer magnolia, weeping willow, Yoshino cherry tree, and pink velour crape myrtle.

Timing

Zone 6 trees, like flowers and shrubs, should be planted before the first and last frost dates. The first frost in Ohio is usually between the end of September and the end of October, and the last is from the last week in March to the last week in April.

Temperature

Buckeye trees thrive in temperatures between -20°F to -10°F. Like Zone 5, native trees already developed in the microclimate grow strong and tall in warmer summers and colder winters.

Hydration

Zone 6 trees are similar to Zone 5 when it comes to watering. It is essential to remember that newly planted trees must be watered daily for the first two weeks, every three to five days for the next three months, and once weekly after three months.

Soil

The best tree soil is from the original planting hole, along with a composite mixture or soil conditioner. Also, assessing the best location for tree planting is essential since some areas lend more clay and sandy soil where trees grow best.

Pruning

Trimming trees and pruning in this zone is the same as in any other zone. Pruning entails removing dead and live branches to free a tree from disease. Trimming a tree is more for growth and shape, eliminating branches for aesthetic sake.

Disease Management

Zone 6 trees, like any other, can also suffer from root disease, which can occur from overwatering. Tree wounds by the base or roots perpetuate root disease. Pruning, trimming, and spraying trees also help them stay healthy and strong.