If you’ve ever purchased something that looked great at the garden center but never thrived or even died once you got it home, you are not alone. It can be tough to understand what conditions some plants prefer based on the garden center tag. Plants have basic needs that vary depending on type of plant. These needs include light, moisture, soil type, and temperature. Understanding the specific conditions in your yard or garden will set you up for success when purchasing plants. Plant tags provide essential information to help gardeners quickly tell what kinds of conditions are suitable for the plant. Tags often include the plant’s name, hardiness zone, light needs, and moisture requirements.

Cold hardiness and heat zone maps are great tools. The USDA Plant Hardiness Zone Map shows the average annual minimum temperature for an area. This tells gardeners how cold it can get and helps them choose plants that can survive the average minimum winter temperatures. In Richmond County, we are zone 8a. This means our average annual minimum winter temperature is between 10 and 15 degrees fahrenheit. However, this isn’t the full story. Just because a plant can survive our winters does not mean they can survive our summers. This is where heat zone maps are useful. The American Horticulture Society created a heat zone map in 1997; however, The Sustainable Gardening Institute has developed an updated map. These maps are based on the average number of “heat days” per year. These are days where the temperature exceeds 86 degrees fahrenheit. This map helps identify plants that can tolerate summer heat stress. These maps used together help paint a more complete picture of where a plant will be most comfortable. 

Another factor to consider is light. A common mistake gardeners make is giving a plant too much or too little sunlight. Consider these definitions when deciding on a plant. Full sun is defined as 6 or more hours of direct, unfiltered sunlight per day. Partial sun or light shade is defined as receiving between four and six hours of direct sun. Keep in mind that afternoon sun is hotter and more intense than morning sun so for some plants it matters when they are receiving that light. Plants that receive too much hot afternoon sun can become scorched. Partial shade is two to four hours of direct sun or shaded for at least half the day. Plants that prefer more shade will tend to do best when in direct sunlight in the morning versus the afternoon. Full shade is less than one hour of direct sunlight each day. It can also mean dappled light through a tree canopy for most of the day. Dense shade means no direct or very little indirect sunlight. This would be the light under evergreen trees, shrubs, decks, or passages between houses.

Soil drainage plays an important role in a plant’s ability to thrive in a landscape and is often related to soil type. Sandy soils often drain quickly while heavy clay soils can take longer. Most garden plants will prefer moist well-drained soils. This is soil that drains reasonably quickly and does not pool. Standing water or soil that stays saturated deprives roots or oxygen. Sites that tend to have poor drainage are heavy clay, depressions, high water tables, and hard pans or rock layers. A simple test can be used to determine the type of drainage your site has. Simply dig a 12 by 12 inch hole that is 12 to 18 inches deep. Fill it with water and let the water drain. Fill the hole with water again and time how long it takes to drain again. Well drained soil should go down at a rate of 1 to 3 inches per hour. A faster rate may indicate a potentially dry site and a slower rate may mean poor drainage. For dry sites consider installing irrigation or choosing plants that tolerant drought conditions. If your soil is poorly drained consider plants that can tolerate being wet for a longer period of time. Whether your site is dry or poorly drained, compost is a great amendment to both increase water holding capacity in sandy soils and increase draining in heavy clays. 

There are excellent tools you can utilize when making planting decisions. One of my favorites is The NC State Extension Gardener Plant Toolbox created by NC State Extension . This is a website where you can search plants to learn more about them. In addition, it has a feature called ‘Find a Plant’ where you can filter plants for your site conditions, plant characteristics, and uses in the landscape. For more information on how to use this tool or any other tool discussed in this article, please contact your local Cooperative Extension Office.