Plants Sun vs Shade
Understanding Plant Light Requirements
The amount and quality of light on your property can change over time, especially in landscapes with maturing trees and shrubs or with new buildings and fences. While established turfgrass and other sun-loving plants might grow successfully in shady areas for a while, many times we start to see them decline, becoming thinner and less dense.
Flowering plants might even stop blooming as the shade begins to encroach on areas that have typically received higher amounts of sunlight. Over-watering and/or over-fertilizing are often the responses to growing plants that are better adapted to sunlight in lower light situations. These poor management practices can be detrimental to your landscape and the environment in the long run.
On the other hand, shade-loving species will also struggle in the Texas heat when planted in the wrong place. While some plants might thrive with the gentler morning sun, the harsher western exposure might just be to much!
Light Conditions Defined
If parts of your landscape do not receive at least 5 hours of sunlight, turfgrass and other sun- loving plants may not be the best option. Texas A&M AgriLife’s Water University has a variety of resources to help you choose the best options for the shaded areas of your landscape.
Seasonal Sun Positioning
Earth’s path around the sun is not a perfect circle. Our varying distance from the sun at different times of the year causes the sun to hold different positions in the sky as seasons change. These positions will cause trees and other structures to cast shade at varying angles throughout the year. Keep this in mind while selecting the most viable plants for the shaded areas of your landscape.
Put the Right Plant in the Right Place
A healthy plant is a valuable asset, but to ensure the best success, it needs to be planted properly and in the right place, depending on the specific requirements for that plant.
Remember, native and adapted plants are the best choice for your landscape, including areas with limited sunlight where turfgrass will not grow. Whatever look you are going for, there are a number of sun AND shade tolerant plants with a variety of structures, textures and colors to work with.
Read the plant tag, and pay close attention to the light requirement, size and spacing of that plant. Proper spacing is even more important in shade conditions to avoid fungal and disease problems.
Gardening Under Trees
Mature trees are one of the most valuable components of a landscape, whether for their aesthetic beauty alone or their numerous economic and environmental benefits like:
- Providing oxygen and clean the air
- Cooling surrounding areas (including your home)
- Helping to prevent soil erosion and water pollution
- Providing food and habitat for wildlife
- Increasing property values
Use caution when planting under mature trees. Deep tilling can damage, not only the surface roots, but also the fine feeder roots that absorb water and nutrients. Covering or damaging the roots creates entryways for insects and diseases to enter and damage or kill your tree. Remember when planting under trees to:
- Dig relatively small holes.
- Carefully plant between major roots and let the plants fill in the area.
- Maintain a 2”- 4” layer of mulch on the soil surrounding the tree, being sure to keep the base or root flare of the tree uncovered.
Although light pruning by a certified arborist can be done to promote the long-term health of a tree, we do NOT promote over- pruning techniques strictly to increase light infiltration, especially techniques that affect mature branches like:
- Limbing up (crown-raising) - the removal of lower branches to greatly increase the distance of branches from the ground
- Pollarding - the removal of upper tree branches
Mature trees, especially evergreens, benefit when healthy lower branches are left intact. Removing large limbs can increase the risk of decay, and over pruning removes much of the tree’s energy absorbing needles or leaves. It can also cause undue stress, negatively impacting the health and vigor of the tree.
Patios and Sitting Areas
Another great option for utilizing the space under a large tree is to install a shaded sitting area. There are a number of pervious paving materials to consider, which not only look great, but also allow water to infiltrate and to be used by the tree. Paving bricks, flagstones and products like decomposed granite also allow water and oxygen exchange in the root zone as opposed to solid (impervious) concrete surfaces, which can be harmful to the tree. Shade trees and adapted perennials also provide inviting areas that stay cool in the warmer months of North Texas.
Shade Gardening Tips
Determine the various degrees of shade in your yard- i.e. How much sunlight and when? A good idea is to take a photograph from the same place in your yard at 8 am, noon and 5 pm. This will show you where shade covers your landscape at different times of day. Some plants might tolerate some morning sun, but burn up in the heat of the afternoon sun.
Try shade loving plants where turfgrass won’t grow. Ornamental trees, shrubs, ferns, ornamental grasses and groundcovers, mulch pathways and even sitting areas with pervious paving are strong solutions for replacing turfgrass in the shade. There is a whole new world of plant material that not only tolerates, but thrives in the shade. These shade-loving plants vary tremendously in their form, foliage and colors of their blooms!
Pay attention to shadows of nearby buildings, fences, shrubs and trees. A tree, shrub, building or fence should be considered an asset, serving as a backdrop or structural focal point that can complement and enhance your plantings.
Be careful when planting- Don’t damage tree roots! Take care to avoid damaging roots, which can extend past the drip-line, when working under or near trees. The drip line is the area under a tree’s canopy.
Water only as needed - Infrequently and deeply! We see even less water loss in shaded areas, both in the plants themselves with slower transpiration rates and reduced evaporation from the soil.