Q: What do “partial shade” and “well-draining soil” mean on a plant tag? When purchasing a plant, I always check the light and water requirements for the plant, but I am never sure of what these two terms mean. I have one shady area in my garden and the rest is mostly full sun. In both areas I have plants in containers. I am never sure of how much to water either of these areas. Help!
A. Frequently, the instructions given on a plant tag for partial shade and well-draining soil are troublesome, especially when trying to figure out where to put a plant with these requirements.
Partial shade and partial sun may seem synonymous, and they are close in meaning. But the main difference between the two terms is the length of sunlight the plants can tolerate.
Below is a rough explanation of commonly used terms found on a plant tag. It includes information on how to determine if your soil is well-draining soil, light requirements, and watering information.
General Light Requirements
Full sun plants need at least six hours of direct sunlight a day. Fruits, vegetables, and many shrubs and flowers grow well in full sun.
Part sun plants need at least four hours and up to six hours of direct sunlight. Petunias, begonias, geraniums, and black-eyed Susan’s like part sun areas.
Partial or (dappled shade) plants need at least three hours of sun and no more than four. These plants may suffer in the afternoon sun. Morning sunlight is the best and/or filtered light for the rest of the day. Hosta, Heucheras (Coral Bells), and Astilbe perform well in partial shade.
Full shade — Full shade does not necessarily mean no sun. These plants will do well with a couple of hours of morning sunlight or less and filtered or shadowed sunlight (shaded by a building, tree, or fence) or complete shade for the rest of the day. Hosta, Liriope, Ferns, and Caladiums are a few examples of full-shade plants.
Well-draining soil allows water to saturate the ground then drain away and not pool for any length of time.
To check your soil, dig a hole in the planting area 12-18 inches deep and 3-4 inches wide when the soil is dry. Fill the hole with water and allow it to drain. Wait 10-12 hours and refill the hole and then time how long it takes it to drain.
If the soil is well-draining, the water should drain out at a rate of 2-3 inches per hour. Any time significantly less than 1-inch per hour indicates poor draining soil. Planting in poor draining soil is never a good idea. You can try to amend it with mulch, compost, and organic matter and see if that helps, but it may be best to look for another location for your plant.
Determining Depth of Moisture
When determining the depth of moisture in a plant scratch the top inch of soil with a wood dowel. If the dowel comes out clean, the plant is too dry. You can use your index figure instead of a wood dowel.
This method does not work with succulents. Containers need more frequent watering than in-ground plants, so check them more often. It is best to try to use plants that have similar water requirements in the same container. Some plants will require a lot of water and others will not need as much. The plant tags will indicate the watering needs for each plant.
With all the rain we have had this month, and limited sunlight, our gardens are struggling with getting too much water.
Join us for Backyard on a Budget to learn the best trips and tricks, savvy shortcuts, reliable rules and interesting ideas for your backyard this Saturday, July 31 from 9 a.m. to 12 p.m. at the Carroll County Ag Center.
For more information on plant lighting and water requirements, or assistance with any horticultural questions you may have, contact a Master Gardener Extension Volunteer at the UGA Cooperative Extension Carroll County Office at 900 Newnan Road in Carrollton. Phone 770-836-8546 or via e-mail at firstname.lastname@example.org.